Zithromax is used to treat many different types of infections caused by bacteria, such as respiratory infections, skin infections, ear infections, and sexually transmitted diseases. In children, it is used to treat middle ear infection, pneumonia, tonsillitis, and strep throat.
GO TO STORE >>
Zithromax is used to treat many different types of infections caused by bacteria, such as respiratory infections, skin infections, ear infections, and sexually transmitted diseases. In children, it is used to treat middle ear infection, pneumonia, tonsillitis, and strep throat.
Active Ingredient: Azithromycin
Zithromax (Azimycin) as known as: Altezym, Amovin, Amsati, Arzomicin, Asizith, Atizor, Azadose, Azalid, Azatril, Azenil, Azi-once, Azibiot, Azicid, Azicin, Azicine, Azicip, Azicu, Azidraw, Azifast, Azigram, Azihexal, Azilide, Azimac, Azimakrol, Azimax, Azimed, Azimex, Azimit, Azimycin, Azin, Azinil, Azinix, Azinom, Aziphar, Azirox, Azithin, Azithral, Azithrex, Azithro, Azithrocin, Azithrocine, Azithromax, Azithromycinum, Azithrox, Azithrus, Azitral, Azitrim, Azitrin, Azitrix, Azitro, Azitrobac, Azitrocin, Azitrohexal, Azitrolit, Azitrom, Azitromicina, Azitropharma, Azitrotek, Azitrovid, Azitrox, Aziwok, Azix, Azomac, Azomax, Azomex, Azomycin, Azro, Azrolid, Azromax, Aztrin, Azycyna, Azyter, Azyth, Bactexina, Bactrazol, Bezanin, Binozyt, Cinalid, Clearsing, Co azithromycin, Disithrom, Doromax, Doyle, Ericiclina, Ezith, Fabramicina, Faxin, Figothrom, Fuqixing, Goldamycin, Goxil, Gramokil, Hemomycin, I-thro, Ilozin, Imbys, Inedol, Iramicina, Koptin, Kromicin, Macromax, Macrozit, Maczith, Magnabiotic, Marvitrox, Medimacrol, Mezatrin, Misultina, Momicine, Naxocina, Neblic, Neofarmiz, Neozith, Nifostin, Nor-zimax, Novatrex, Novozithron, Novozitron, Odaz, Odazyth, Opeazitro, Oranex, Ordipha, Orobiotic, Penalox, Phagocin, Pretir, Rarpezit, Respazit, Ribotrex, Ricilina, Rozith, Saver, Simpli, Sitrox, Sumamed, Talcilina, Tanezox, Texis, Thiza, Toraseptol, Tremac, Trex, Tri azit, Triamid, Tridosil, Tritab, Tromic, Tromix, Trozocina, Ultrabac, Ultreon, Unizitro, Vectocilina, Vinzam, Zaret, Zedd, Zemycin, Zentavion, Zertalin, Zetamax, Zeto, Zi-factor, Zibac, Zibramax, Zicho, Zifin, Zimax, Zinfect, Zirocin, Zistic, Zithrin, Zithrocin, Zithrogen, Zithromac, Zithromycin, Zithrox, Zitrex, Zitrim, Zitrocin, Zitrofar, Zitroken, Zitrolab, Zitrolid, Zitromax, Zitroneo, Zitrotek, Zival, Zmax, Zocin, Zomax, Zycin, Zymycin
The Elephant Formulary
© 2003-06 Susan K. Mikota DVM and Donald C. Plumb, Pharm.D.
Published by Elephant Care International - www.elephantcare.org
Elephant specific information, if available, is in blue.
Chemistry - A propylamine (alkylamine) antihistaminic agent, chlorpheniramine maleate occurs as an odorless, white, crystalline powder with a melting point between 130 - 135° C and a pK a of 9.2. One gram is soluble in about 4 ml of water, or 10 ml of alcohol. The pH of the commercially available injection is between 4 - 5.2.
Storage/Stability/Compatibility - Chlorpheniramine tablets and sustained-release tablets should be store in tight containers. The sustained-release capsules should be stored in well-closed containers. The oral solution and injectable products should be stored in light-resistant containers; avoid freezing. All chlorpheniramine products should be stored at room temperature (15-30°C).
Chlorpheniramine for injection is reportedly compatible with most commonly used IV solutions and the following drugs: amikacin sulfate, diatrizoate meglumine 52%/diatrizoate sodium 8% (Renografin-60 ® ), diatrizoate meglumine 34.3%/diatrizoate sodium 35% (Renovist ® ), diatrizoate sodium 75% (Hypaque ® ), iothalamate meglumine 60% (Conray ® ), and iothalamate sodium 80% (Angio-Conray ® ).
Chlorpheniramine is reportedly incompatible with: calcium chloride, kanamycin sulfate, norepinephrine bitartrate, pentobarbital sodium, and iodipamide meglumine 52% (Cholographin ® ). Compatibility is dependent upon factors such as pH, concentration, temperature, and diluents used and it is suggested to consult specialized references for more specific information.
Pharmacology - Antihistamines (H 1 -receptor antagonists) competitively inhibit histamine at H 1 receptor sites. They do not inactivate or prevent the release of histamine, but can prevent histamine’s action on the cell. Besides their antihistaminic activity, these agents all have varying degrees of anticholinergic and CNS activity (sedation). Some antihistamines have antiemetic activity (e.g. diphenhydramine) or antiseritonin activity (e.g., cyproheptadine, azatadine).
Uses/Indications - Antihistamines are used in veterinary medicine to reduce or help prevent histamine mediated adverse effects.
Pharmacokinetics - Chlorpheniramine pharmacokinetics have not been described in domestic species. In humans, the drug is well absorbed after oral administration, but because of a relatively high degree of metabolism in the GI mucosa and the liver, only about 25-60% of the drug is available to the systemic circulation.
Chlorpheniramine is well distributed after IV injection, the highest distribution of the drug (in rabbits) occurs in the lungs, heart, kidneys, brain, small intestine and spleen. In humans, the apparent steady-state volume of distribution is 2.5 - 3.2 L/kg and it is about 70% bound to plasma proteins. It is unknown if chlorpheniramine is excreted into the milk.
Chlorpheniramine is metabolized in the liver and practically all the drug (as metabolites and unchanged drug) is excreted in the urine. In human patients with normal renal and hepatic function, the terminal serum half-life the drug ranges from 13.2-43 hours.
Contraindications/Precautions - Chlorpheniramine is contraindicated in patients who are hypersensitive to it or other antihistamines in its class. Because of their anticholinergic activity, antihistamines should be used with caution in patients with angle closure glaucoma, prostatic hypertrophy, pyloroduodenal or bladder neck obstruction, and COPD if mucosal secretions are a problem. Additionally, they should be cautiously used in patients with hyperthyroidism, cardiovascular disease or hypertension.
Adverse Effects/Warnings - Most commonly seen adverse effects are CNS depression (lethargy, somnolence) and GI effects (diarrhea, vomiting, anorexia). The sedative effects of antihistamines may diminish with time. Anticholinergic effects (dry mouth, urinary retention) are a possibility. The sedative effects of antihistamines may adversely affect the performance of working dogs.
Overdosage - Overdosage may cause CNS stimulation (excitement to seizures) or depression (lethargy to coma), anticholinergic effects, respiratory depression, and death. Treatment consists of emptying the gut if the ingestion was oral using standard protocols. Induce emesis if the patient is alert and CNS status is stable. Administration of a saline cathartic and/or activated charcoal may be given after emesis or gastric lavage. Treatment of other symptoms should be performed using symptomatic and supportive therapies. Phenytoin (IV) is recommended in the treatment of seizures caused by antihistamine overdose in humans; barbiturates and diazepam are avoided.
Drug Interactions - Increased sedation can occur if chlorpheniramine is combined with other CNS depressant drugs. Antihistamines may partially counteract the anticoagulation effects of heparin or warfarin.
Laboratory Interactions - Antihistamines can decrease the wheal and flare response to antigen skin testing. In humans, it is suggested that antihistamines be discontinued at least 4 days before testing.
Doses - Note: Contents of sustained-release capsules may be placed on food, but should not be allowed to dissolve before ingestion.
a) 4 - 8 mg PO q12h (Kirk 1986)
b) 2 - 4 mg PO bid -tid (Morgan 1988)
As an antihistamine:
a) Pheniramine: 1700-2300 mg/animal in Asian elephants; author’s personal experience (Cheeran, 1995).
a) Cheeran,J.V. Chandrasekharan,K. and Radhakrishnan,K. 1995. Principles andPractice of Fixing Dose of Drugs for Elephants. In: Daniel,J.C. (Editor), A Week with Elephants; Proceedings of the International Seminar on Asian Elephants. Bombay Natural History Society; Oxford University Press, Bombay, India pp. 430-438
1) Clinical efficacy and adverse effects
Client Information/FDA Approval Status - Except in the combination products listed below, no veterinary-approved product is available. Chlorpheniramine is approved for use in humans; the oral dosage forms are either prescription or non-prescription agents, depending on the product’s labeling. The injectable products are prescription only.
Veterinary-Approved Products. None None as a single entity. This compound is also found in the veterinary-approved (dogs, cats, horses) products Diathal ® (Schering) and Azimycin ® (Schering). Diathal ® contains: chlorpheniramine maleate 10 mg/ml, procaine penicillin G 200,000 U/ml, dihydrostreptomycin sulfate 250 mg/ml and diphemanil methylsulfate 25 mg/ml. Azimycin ® contains: chlorpheniramine maleate 10 mg/ml, procaine penicillin G 200,000 U/ml, dihydrostreptomycin sulfate 250 mg/ml, dexamethasone 0.5 mg/ml, and procaine HCl 20 mg/ml.
Chlorpheniramine Maleate Oral Tablets 2 mg (chewable), 4 mg, 8 mg (timed release), 12 mg (timed release) (OTC)
Chlorpheniramine Maleate Oral Syrup 2 mg/5 ml in 118 ml btls (OTC)
Chlorpheniramine Maleate Injection 10 mg/ml in 30 ml vials & 100 mg/ml in 10 ml vials; (Rx)
There are many registered trade names for chlorpheniramine; a commonly known product is Chlor-Trimeton ® (Schering). Many combination products are available that combine chlorpheniramine with decongestants, analgesics, and/or antitussives.
Disclaimer: the information on this page is used entirely at the reader's discretion,
and is made available on the express condition that no liability, expressed or implied,
is accepted by the authors or publisher for the accuracy, content, or use thereof.
Gdzie można kupić Azimycin ?Szukasz gdzie można kupić Azimycin ?
Wyszukaj gdzie najlepiej kupić Azimycin – use the following search enginesPost navigation The price of medicines and NHF refund
Thank you that you are visiting our site. Information about the prices of medicines are poglądowymi information and please verify them on specific vendors. Medicines reimbursed by NFZ change often and it can happen, that is an error on the page for that sorry.Help The Lence
Composit uses/ indication of Azimycin 500mg :
Bacterial infections like middle ear infections, strep throat, pneumonia, typhoid, and sinusitis. sexually transmitted infections, such as nongonococcal urethritis, chlamydia, and cervicitis. pneumonia, cellulitis, babesiosis, Bartonella infection, chancroid cholera, donovanosis, leptospirosis, Lyme disease, malaria, Mycobacterium avium complex disease, Neisseria meningitis, pelvic inflammatory disease, pertussis, scrub typhus, toxoplasmosis, and salmonellosis. traveler's diarrhea, acute otitis media, nonstreptococcal bacterial pharyngitis.
Composit contra indication of Azimycin 500mg :
Hypersensitivity to azithromycin or any other macrolide or ketolide antibiotics
Composit side effects of Azimycin 500mg :
Nausea, vomiting, abdominal pain, diarrhoea, dyspepsia, flatulence, dizziness, headache, vertigo.
Composit caution of Azimycin 500mg :
Pseudomembranous colitis, impaired liver function, impaired renal function, antacids containing aluminium and magnesium, children.
If you are Pharmaceutical manufacturer. contract manufacturer, machine manufacturer. bulk drug manufacturer or provide facility like pharmaceutical product printing. packaging and consulting then dawabazar.in is a perfect place to promote your business with your brand/products/services.
Create profile and manage brand/products/services for free and get listed in various search
If you are Pharmaceutical dealer, supplier, stokist. wholeseller or distributor and deales in allopathy medicines, ayurvedic medicines, homeopathic medicines. scientific instruments ,pharmaceutical machinery. surgical appliances and instruments. medical devices and health devices then this website is for you to enhance your business.
Create profile and manage products for free and get listed in various search
If you are pharmaceutical retailer or chemist then this place for you to increase your sales and get medicine enquiry from common person. You can find pharmaceutical dealers and stockiest list according to your city for any pharmaceutical company and its product.
Create profile for free and get listed in various search
Dawabazar.in is a free content encyclopedia especially for pharmaceutical field. This website provides information about all manufacturing. marketing companies and their products, its compositions along with its dealers. retailers in India. This website also provides many findings on medicines, Pharma companies ,Pharma dealers, Pharma retailers, active pharmaceutical ingredients, therapeutic index and pharmacological index which is useful for doctors. medical students and common person.
24 April 2014 - 22:37:59 ADMIN
Angina, or chest pain, is the most common symptom of coronary artery disease. Caused by ischemia, angina is often due to a clot forming in a partially blocked coronary artery. Angina can be described as discomfort or heaviness in the chest. Too often, this acute and dangerous symptom is passed off as simple indigestion or heartburn.
More than 6 million Americans suffer with angina, or chest pain. Angina is a specific type of chest pain that occurs when a part (or parts) of the heart do not get adequate blood flow (ischemia). Angina is often described as a heavy feeling in the chest, as well as tightness, pressure, deep ache, squeezing or fullness. While angina is mostly felt in the chest area, it may also be felt in other parts of the body, such as the arms, jaw or back. Angina might be accompanied by other symptoms that are suggestive of a heart attack, such as nausea, sweating or palpitations. In a heart attack, angina is usually more severe, usually lasting longer than five minutes, and medication or rest does not relieve the pain. Patients are urged to err on the side of caution. For angina lasting more than five minutes, call an ambulance and get emergency medical help.
Angina you did not find the exact information you're looking for?
Angina you're wondering about a problem to us, just us answer.
This article has no comments yet.Most Read Articles Latest Articles
What Research Is Being Conducted on Acne?
Disease List Information about diseases in health portal.
26.04.2016 Tuesday 21:27
There is an additional general information about this medication active ingredient azithromycin:Pharmacological action
Azithromycin is an macrolide antibiotic of azalides group. This medication inhibits RNA-dependent protein synthesis of sensitive microorganisms.
It active against gram-positive bacteria: Staphylococcus aureus, Streptococcus spp. (including Streptococcus pneumoniae, Streptococcus pyogenes group A); gram-negative bacteria: Haemophilus influenzae, Haemophilus parainfluenzae, Haemophilus ducreyi, Moraxella catarrhalis, Escherichia coli, Bordetella pertussis, Bordetella parapertussis, Borrelia burgdorferi, Neisseria gonorrhoeae, Campylobacter spp. Legionella pneumophila; anaerobic bacteria: Bacteroides fragilis.
This drug rapidly absorbed from the gastrointestinal tract. Ingestion reduces the absorption of azithromycin. Cmax in plasma is reached after 2-3 hours. This medicine rapidly distributed in tissues and biological fluids. 35% of the azithromycin is metabolized in the liver by demethylation. More than 59% is excreted in the bile in unchanged form, about 4.5% in the urine in unchanged form.Why is Azimycin prescribed?
Infectious-inflammatory diseases caused by microorganisms susceptible to azithromycin, including bronchitis, pneumonia, infections of skin and soft tissue, otitis media, sinusitis, pharyngitis, tonsillitis, gonorrheal and non gonorrheal urethritis and / or cervicitis, Lyme disease (borreliosis).Dosage and administration
Dosage is setted individually according to nosology, disease severity and sensitivity of the pathogen. Dosage for adults for oral administration is 0.25-1 g 1 time/day; for children - 5-10 mg/kg 1 time/day. The duration of administration is 2-5 days.Azimycin side effects
Digestive system: nausea, vomiting, flatulence, diarrhea, abdominal pain, transient elevation of liver enzymes, rarely - cholestatic jaundice.
Allergic reactions: rarely - a skin rash, angioedema, erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis.
Dermatological reactions: rarely - photosensitization.
CNS: dizziness, headache, rarely - drowsiness, weakness.
Hematopoietic system: rarely - leukopenia, neutropenia, thrombocytopenia.
Cardiovascular system: rarely - chest pain.
Urogenital system: vaginitis, rarely - candidiasis, nephritis, increased residual nitrogen urea.
Other: rarely - hyperglycemia, arthralgia.
Hypersensitivity to azithromycin and other macrolide antibiotics.Using during pregnancy and breastfeeding
Azithromycin crosses the placental barrier. Use in pregnancy only in cases where the intended benefits to the mother outweighs the potential risk to the fetus.
If necessary to use azithromycin in the lactation period should solve the issue of termination of breastfeeding.
This drug not recommended for use in patients with compromised liver function.
Azithromycin uses with careful with impaired renal function.
This medication should be taken at least 1 hour before or 2 hours after eating or taking of antacids.
PLEASE, BE CAREFUL!
Be sure to consult your doctor before taking any medication!
Zithromax is used for treating mild to moderate infections caused by certain bacteria. It may also be used alone or with other medicines to treat or prevent certain infections in persons with advanced HIV infection. Zithromax is a macrolide antibiotic. It slows the growth of, or sometimes kills, sensitive bacteria by reducing the production of important proteins needed by the bacteria to survive.
Use Zithromax as directed by your doctor.
Ask your health care provider any questions you may have about how to use Zithromax.
Store Zithromax below 86 degrees F (30 degrees C). Store away from heat, moisture, and light. Do not store in the bathroom. Keep Zithromax out of the reach of children and away from pets.
Active Ingredient: Azithromycin.
Do NOT use Zithromax if:
Contact your doctor or health care provider right away if any of these apply to you.
Some medical conditions may interact with Zithromax. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:
Some medicines may interact with Zithromax. Tell your health care provider if you are taking any other medicines, especially any of the following:
This may not be a complete list of all interactions that may occur. Ask your health care provider if Zithromax may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.Important safety information:
All medicines may cause side effects, but many people have no, or minor, side effects.
Check with your doctor if any of these most common side effects persist or become bothersome:
Diarrhea; headache; loose stools; nausea; stomach pain; upset stomach; vomiting.
Seek medical attention right away if any of these severe side effects occur:
Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue; unusual hoarseness); bloody stools; changes in hearing or hearing loss; chest pain; eye or vision problems; irregular heartbeat; muscle weakness; pounding in the chest; red, swollen, blistered, or peeling skin; ringing in the ears; seizure; severe diarrhea; stomach cramps/pain; trouble speaking or swallowing; yellowing of the skin or eyes.
This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider.
Customers who bought this product also bought:
Ampicillin Ampicillin is used to treat many different types of infections caused by bacteria, such as ear infections, bladder infections, pneumonia, gonorrhea, and E. coli or salmonella infection. as low as $0.26 Bactrim Bactrim is used to treat ear infections, urinary tract infections, bronchitis, traveler's diarrhea, and Pneumocystis carinii pneumonia. as low as $0.39 Ciplox Ciplox is an antibiotic in a group of drugs called fluoroquinolones. It is used to fight bacteria in the body. as low as $1.36 Keflex Keflex is used to treat infections caused by bacteria, including upper respiratory infections, ear infections, skin infections, and urinary tract infections. as low as $0.98 Tinidazole Tinidazole is used for treating certain parasitic and bacterial infections. as low as $0.92 Cefadroxil Cefadroxil is used to treat many different types of infections caused by bacteria. as low as $1.13
Among these sixteen crystal forms, two isomorphic families are identified. Family I includes forms F, G, H, J, M, N, O, and P. Family II includes forms C, D, E and R. Form Q is distinct from families I and II. The forms within a family are isomorphs that crystallize in the same space group with slight variation of cell parameters and comprise chemically related structures but different elemental composition. In this case, the variation in chemical composition among the isomorphs arises from incorporation of different water/solvent molecules. Consequently, the isomorphs display similar but non-identical X-ray diffraction patterns and solid-state NMR spectra (ssNMR). Other techniques such as near infrared spectroscopy (NIR), differential scanning calorimetry (DSC), gas chromatography (GC), thermalgravimetric analysis (TGA), or thermalgravimetric analysis/infrared spectroscopy analysis (TG-IR), Karl Fischer water analysis (KF) and molecular modeling/visualization provide data for affirmative identification of isomorphs. Dehydration/desolvation temperatures were determined by DSC with a heating rate of 5°C/min
Form C. This crystal form was identified from a single crystal structure (Table 2) - a monohydrate of azithromycin. It has the space group of P21 21 21 and similar cell parameters as that of forms D and E; therefore, it belongs to Family II isomorphs. Its calculated powder pattern is similar to that of forms D and E.
Form D. Form D was crystallized from cyclohexane. The single crystal structure of form D shows a stoichiometry of a monohydrate/monocyclohexane solvate of azithromycin (Table 3). Cyclohexane molecules were found to be disordered in the crystal lattice. From single crystal data, the calculated water and cyclohexane content of form D is 2.1 and 9.9%, respectively. Both the powder pattern and the calculated powder pattern of form D are similar to those of forms C and E. The powder samples of form D showed a desolvation/dehydration endotherm with an onset temperature of about 87°C and a broad endotherm between 200-280°C (decomposition) in DSC analysis at 5°C/min from 30-300°C.
Form D is prepared by slurrying azithromycin in cyclohexane for 2-4 days. The solid form D azithromycin is collected by filtration and dried.
Form E. Form E was obtained as a single crystal collected in a THF/water medium. It is a monohydrate and mono-THF solvate by single crystal analysis (Table 4). By its single crystal structure, the calculated PXRD pattern is similar to that of form C and form D making it a family II isomorph.
Form E is prepared by dissolving azithromycin in THF (tetrahydrofuran). Diffusing water vapor to saturated azithromycin THF solution over time yields crystals of Form E.
Form F. The single crystal of form F crystallized in a monoclinic space group, P21. with the asymmetric unit containing two azithromycin, two waters, and one ethanol, as a monohydrate/hemi-ethanolate (Table 5). It is isomorphic to forms all family I azithromycin crystalline forms. The calculated PXRD pattern of this form is similar to those of other family I isomorphs. The theoretical water and ethanol contents are 2.3 and 2.9%, respectively. The powder samples show a dehydration/desolvation endotherm at an onset temperature between 110-125°C. Form F is prepared by dissolving azithromycin in ethanol (1-3 volumes by weight) at a temperature of about 50-70°C. Upon complete dissolution, the solution is cooled to subambient temperature to cause precipitation. The volume of ethanol can be reduced by vacuum distillation with stirring for 1-2 hours to increase the yield. Alternatively, water (optionally chilled to 0-20°C) about 0.1-2 volume can be added with collection of solids within 30 minute after water addition. Cooling the ethanol solution of azithromycin prior to the addition of water to below below 20°C, preferably below 15°C, more preferably below 10, and most preferably 5°C results in substantially pure azithromycin form F. The solid form F azithromycin is collected by filtration and dried.
Form G: The single crystal structure of form G consists of two azithromycin molecules and three water molecules per asymmetric unit (Table 6). This corresponds to a sesquihydrate with a theoretical water content of 3.5%. The water content of powder samples of form G ranges from about 2.5 to about 6%. The total residual organic solvent is less than 1% of the corresponding solvent used for crystallization, which is well below stoichiometric quantities of solvate. This form dehydrates with an onset temperature of about 110 -120°C.
Form G may be prepared by adding azithromycin to a premixed organic solvent/water mixture (1/1 by volume), where the organic solvent can be methanol, acetone, acetonitrile, ethanol or isopropanol. The mixture is stirred and heated to an elevated temperature, e.g. 45-55°C for 4-6 hours to cause dissolution. Precipitation occurs during cooling to ambient temperature. The solid form G azithromycin is collected by filtration and dried.
Form H: This crystal form is a monohydrate/hemi-propylene glycol solvate of azithromycin free base (Table 7). It was isolated from a formulation solution containing propylene glycol. The crystal structure of form H is isomorphic to crystal forms of Family I.
Azithromycin form H is prepared by dissolving azithromycin dihydrate in 6 volumes of propylene glycol. To the resulting propylene glycol solution of azithromycin, 2 volumes of water is added and precipitation occurrs. The slurry is stirred for 24 hours and the solids are filtered and air-dried at ambient temperature to afford crystalline Form H.
Form J: Form J is a monohydrate/hemi n-propanol solvate (Table 8). The calculated solvent content is about 3.8% n-propanol and about 2.3% water. The experimental data shows from about 2.5 to about 4.0% n-propanol and from about 2.5 to about 3% water content for powder samples. Its PXRD pattern is very similar to those of its isomorphs F, G, H, M and N. Like F and G, the powder samples have a dehydration/desolvation endotherm at 115 - 125°C.
Form J is prepared by dissolving azithromycin in 4 volumes of n-propanol at a temperature of about 25-55°C. Water, about 6-7 volumes, is added at room temperature and the slurry is continuously stirred for 0.5-2 hours. The solid form J azithromycin is collected by filtration and dried.
Form K. The PXRD pattern of form K was found in a mixture of azithromycin form A and microcrystalline wax after annealing at 95°C for 3 hours. It is a lower hydrate of form A and is a metastable high temperature form.
Form L. This form has only been observed upon heating the dihydrate; form A. In variable temperature powder X-ray diffraction (VT-PXRD) experiments, a new powder X-ray diffraction pattern appears when form A is heated to about 90°C. The new form, designated form L, is a lower hydrate of form A because form A loses about 2.5 weight % at 90 °C by TGA, thus corresponding to a conversion to a monohydrate. When cooled to ambient temperature, form L rapidly reverts to form A.
Form M: Isolated from an isopropanol/water slurry, form M incorporates both water and isopropanol. Its PXRD pattern and ss-NMR spectrum are very similar to those of Family I isomorphs, indicating that it belongs to Family I. By analogy to the known crystal structures of Family 1 isomorphs, the single crystal structure of form M would be a monohydrate/hemi-isopropranolate. The dehydration/desolvation temperature of form M is about 115-125°C.
Form M may be prepared by dissolving azithromycin in 2-3 volumes of isopropanol (IPA) at 40-50°C. The solution is cooled to below 15°C, preferably below 10°C, more preferably about 5°C and 2-4 volumes of cold water about 5°C are added to effect precipitation. Seeds of form M crystals may be added at the onset of crystallization. The slurry is stirred less than about 5 hours, preferably less than about 3 hours, more preferably less than about 1 hour and most preferably about 30 minutes or less and the solids are collected by filtration. The solids may be reslurried in isopropanol. This procedure provides form M substantially in the absence of azithromycin dihydrate.
Form N: Isolated from water/ethanol/isopropanol slurry of form A, form N crystals may contain variable amounts of the crystallization solvents and water. Its water content varies from about 3.4 to about 5.3 weight percent. Analysis by GC Headspace reveals a variable solvent content of ethanol and isopropanol. The total solvent content of form N samples is usually lower than about 5% depending on the conditions of preparation and drying. The PXRD pattern of form N is similar to that of forms F, G, H, J and M of the Family I isomorphs. The dehydration/desolvation endotherm(s) of the samples of form N may be broader and may vary between 110-130°C.
Form N azithromycin may be prepared by recrystallizing azithromycin from a mixture of azithromycin crystal latice-incorporating organic solvents and water, such as ethanol, isopropanol, n-propanol, acetone, acetonitirile etc. The solvent mixture is heated to 45-60°C and azithromycin is added to the heated solvent mixture, up to a total of about 4 volumes. Upon dissolution, 1-3 volumes of water are added with continuous agitation at 45-60°C. Form N azithromycin precipitates as a white solid. The slurry is allowed to cool to ambient temperature with stirring. Solid form N azithromycin is isolated by filtration and dried.
Form O: This crystal form is a hemihydrate hemi-n-butanol solvate of azithromycin free base by single crystal structural data (Table 8A). It was isolated from n-butanol solution of azithromycin with diffusion of antisolvent. The crystal structure of form O is isomorphic to crystal forms of Family I.
Azithromycin is completely dissolved in n-butanol. Addition of an antisolvent, such as hexane, water, IPE or other non-solvent, by diffusion results in precipitation of Form O.
Form P: This is a proposed crystal form, being a hemihydrate hemi-n-pentanol solvate of azithromycin free base. It can be isolated from an n-pentanol solution of azithromycin with diffusion of an antisolvent. The crystal structure of form P is isomorphic to crystal forms of Family I.
Form P of azithromycin may be prepared as following: Azithromycin is completely dissolved in n-pentanol; addition of an antisolvent, such as hexane, water, isopropyl ether (IPE) or other non-solvent, by diffusion results in precipitation of Form P.
Form Q: The crystal form of Q exhibits a unique powder X-ray diffraction pattern. It contains about 4% water and about 4.5% THF, being a hydrate hemi THF solvate. The main dehydration/desolvation temperature is from about 80 to about 110°C.
Azithromycin dihydrate is dissolved in 6 volumes of THF and 2 volumes of water are added. The solution is allowed to evaporate to dryness at ambient conditions to afford crystalline Form Q.
Form R. This crystalline form is prepared by adding amorphous azithromycin to 2.5 volumes of tert-butyl methyl ether (MTBE). The resulting thick white suspension is stirred 3 days at ambient conditions. Solids are collected by vacuum filtration and air dried. The resulting bulk azithromycin form R has a theoretical water content of 2.1 weight % and a theoretical methyl tert-butyl ether content of 10.3 weight %.
Due to the similarity in their structures, isomorphs have propensity to form a mixture of the forms within a family, sometimes termed as 'mixed crystals' or 'crystalline solid solution'. Form N is such a solid crystalline solution and was found to be a mixture of Family I isomorphs by solvent composition and solid-state NMR data.
Both Family I and Family II isomorphs are hydrates and/or solvates of azithromycin. The solvent molecules in the cavities have tendency to exchange between solvent and water under specific conditions. Therefore, the solvent/water content of the isomorphs may vary to a certain extent.
The crystal forms of isomorphic Family I are more stable than form A when subjected to heating. Forms F, G, H, J, M and N showed higher onset dehydration temperatures at 110-125 °C than that of form A with an onset dehydration temperature at about 90 to about 110°C and simultaneous solid-state conversion to form L at about 90°C.
Amorphous azithromycin: All crystal forms of azithromycin contain water or solvent(s) or both water and solvent(s). When water and solvent(s) are removed from the crystalline solids, azithromycin becomes amorphous. Amorphous solids have advantages of high initial dissolution rates.
The starting material for the synthesis of the various crystal forms in the examples below was azithromycin dihydrate unless otherwise noted. Other forms of azithromycin such as amorphous azithromycin or other non-dihydrate crystalline forms of azithromycin may be used.ExamplesExample 1: Preparation of Form D
Form D was prepared by slurrying azithromycin dihydrate in cyclohexane for 2-4 days at an elevated temperature, e.g. 25-50°C. The crystalline solids of form D were collected by filtration and dried.Example 2: Preparation of Form F
2A: Azithromycin dihydrate was slowly added to one volume of warm ethanol, about 70°C, and stirred to complete dissolution at 65 to 70°C. Seeds of Form F 1- 2% wt may be introduced to facilitate the crystallization. The solution was allowed to cool gradually to 2 - 5°C and one volume of chilled water was added The crystalline solids were collected shortly (preferably less than 30 minutes) after addition of water by vacuum filtration.
2B: Azithromycin dihydrate is slowly added to one volume of warm ethanol, about 70°C, and stirred to complete dissolution at 65 to 70°C. Seeds of Form F 1- 2% wt may be introduced to facilitate the crystallization. The solution is allowed to cool gradually to 2 - 5°C and ethanol volume may be reduced by vacuum distillation. After stirring up to 2 hours the crystalline solids are collected by vacuum filtration. The isolation of the crystals yields substantially pure form F azithromycin, form F azithromycin substantially free of form G azithromycin and form F azithromycin substantially free of azithromycin dihydrate.Example 3: Preparation of Form G
A reaction vessel was charged with form A azithromycin. In a separate vessel, 1.5 volumes methanol and 1.5 volumes water were mixed. The solvent mixture was added to the reaction vessel containing the form A azithromycin. The slurry was stirred with heating to 50°C for approximately 5 hours. Heating was discontinued and the slurry was allowed to cool with stirring to ambient temperature. The form G azithromycin was collected by filtration and allowed to air dry for approximately 30 minutes. The collected form G azithromycin was further dried in a vacuum oven at 45°C. This procedure yields substantially pure form G azithromycin, and form G azithromycin substantially free of azithromycin dihydrate.Example 4: Preparation of Form J
Form J was prepared by dissolving azithromycin in 4 volumes of n-propanol at a temperature of about 25°C. Water (6.7 volumes) was added and the slurry is continuously stirred for 1 hour, followed by cooling to about 0°C. The solid form J azithromycin was collected by filtration and dried.Example 5: Preparation of Form M Substantially in the Absence of Azithromycin Dihydrate
5A: Azithromycin dihydrate is completely dissolved in 2 volumes of warm isopropanol 40 - 50°C. Seeds of Form M may be optionally introduced to facilitate the crystallization. The solution is then cooled to 0-5°C and 4 volumes of chilled water as antisolvent are added and the solids are collected by vacuum filtration. The solids are reslurried in 1 volume of isopropanol for 3-5 hours at 40-45 °C and then cooled to 0-5°C. The crystalline solids are collected shortly (about 15 minutes) after addition of water by vacuum filtration. The solids are reslurried in 0.5 to 1 volume of isopropanol at 25-40°C and cooled to about 5°C followed by filtration to collect solids of form M.
5B: Azithromycin dihydrate (1940 grams) was completely dissolved in 2 volumes of warm isopropanol (45°C). The resulting clear solution was filtered through an inline 0.2 µm filter into a clean flask. The temperature was maintained at 45°C and the solution was seeded with form M crystals. 7.8 L of chilled water was added over 8 minutes. The solution was cooled to 5°C and a thick slurry was noted. The solids were isolated by vacuum filtration and transferred to a clean flask. The crystalline azithromycin was slurried in 1 volume of isopropanol alcohol with warming to 35°C. The slurry was then cooled to 5°C for 30 minutes and the solid crystalline material was filtered off.
These procedures yield substantially pure form M azithromycin, form M azithromycin substantially free of form G azithromycin and form M azithromycin substantially free of azithromycin dihydrateExample 6: Preparation of Form N
Two volumes of ethanol and 2 volumes of isopropanol were added to a reaction vessel and heated to 50°C. Azithromycin form A was added with stirring to the heated ethanol/isopropanol mixture to yield a clear solution. The reaction vessel was charged with 2 volumes distilled water (ambient temperature). Stirring was continued at 50°C and solid form N azithromycin precipitated after approximately 1 hr. Heating was discontinued 5 hours after the addition of the water. The slurry was allowed to cool to ambient temperature. Precipitated form N azithromycin was collected by filtration and dried for 4 hours in vacuum oven at 45°C.Example 7: Preparation of amorphous azithromycin
Crystalline form A azithromycin was heated to 110-120°C in an oven for overnight under vacuum. The amorphous solids were collected and stored with desiccant as needed.Example 8: Preparation of Form H
Azithromycin dihydrate or other crystal forms was dissolved in 6 volumes of propylene glycol. To the resulting propylene glycol solution of azithromycin, 2 volumes of water were added and precipitation occurred. The slurry was stirred for 24 hours and the solids were filtered and air-dried at ambient temperature to afford crystalline Form H.Example 9: Preparation of Form Q
The crystalline powder was prepared by dissolving 500 mg azithromycin Form A in 2 ml THF. To the clear, colorless solution at room temperature was added 1 ml water. When the solution became cloudy an additional 1ml THF was added to dissolve the azithromycin completely, and the solution was stirred at ambient temperature. Solvent was allowed to evaporate over 7 days, after which the dry solids were collected and characterized.Example 10: Powder X-ray diffraction analysis
Powder patterns were collected using a Bruker D5000 diffractometer (Madison, Wisconsin) equipped with copper radiation, fixed slits (1.0, 1.0, 0.6mm), and a Kevex solid state detector. Data was collected from 3.0 to 40.0 degrees in 2 theta using a step size of 0.04 degrees and a step time of 1.0 seconds. The results are summarized in Table 9.
The experimental PXRD diffraction pattern of azithromycin form A is given in figure 2.
The experimental PXRD diffraction pattern of azithromycin form D is given in figure 6.
The experimental PXRD diffraction pattern of azithromycin form F is given in figure 10.
The experimental PXRD diffraction pattern of azithromycin form G is given in figure 13.
The experimental PXRD diffraction pattern of azithromycin form J is given in figure 16.
The experimental PXRD diffraction pattern of azithromycin form M is given in figure 18.
The experimental PXRD diffraction pattern of azithromycin form N is given in figure 19.
The experimental PXRD diffraction pattern of amorphous azithromycin is given in figure 20.
The experimental PXRD diffraction pattern of azithromycin form Q is given in figure 30.
The experimental PXRD diffraction pattern of azithromycin form R is given in figure 31.
The experimental variability from sample to sample is about ± 0.2° in 2 theta, and the same variations were observed between the calculated powder from single crystal structure and experimental data. Detailed analysis showed that the isomorphs in Family I can be discerned by PXRD with sets of characteristic peaks given in Table 9.
Table 9, Azithromycin Powder X-ray Diffraction Peaks in 2-theta ±0.2°
The peaks in italic and underlined are the sets of peaks that are characteristic within Family I isomorphs.
Family I isomorphs have the following common characteristics: the diffraction peaks at 6.2, 11.2, 21.0±0.1 and 22.5 ±0.1 degree in 2-theta. Each isomorph displays representative sets of diffraction peaks given in the following, and each set has characteristic spacing between the peaks.
The diffraction peak positions reported are accurate to within ± 0.2 degree of 2-theta.
A representative PXRD pattern of form A is shown in figure 2. Form A displays peaks at 9.3, 13.0 and 18.7 degrees of 2-theta.
A representative PXRD pattern of form D is shown in figure 6. Form D displays peaks at 3.9, 10.1, 10.6 and 21.4 degrees of 2-theta.
A representative PXRD pattern of Form F is shown in figure 10. Form F displays the characteristic peaks of Family I and three sets of peaks, being set 1 at 2-theta of 11.2 and 11.5; set 2 at 2-theta of 13.9, 14.3, 14.7 and 14.8; set 3 at 2-theta of 16.2, 16.6, 17.1, 17.2 and 17.7.
A representative PXRD pattern of Form G is shown in figure 13. Form G displays the characteristic peaks of Family I and three sets of peaks, being set 1 at 2-theta of 11.2 and 11.6 2; set at 2-theta of 14.0, 14.4, 14.6 and 14.9; set 3 at 2-theta of 16.3, 16.6, 17.2, 17.4 and 17.8.
A representative PXRD pattern of Form J is shown in figure 16. Form J displays the characteristic peaks of Family I and three sets of peaks, being set 1 at 2-theta of 11.2 and 11.4; set 2 at 2-theta of 13.9, 14.2 and 14.6; set 3 at 2-theta of 16.0, 16.6, 17.0, 17.2 and 17.5.
A representative PXRD pattern of Form M is shown in figure 18. Form M displays the characteristic peaks of Family I and three sets of peaks, being set 1 at 2-theta of 11.2; set 2 at 2-theta of 14.0 and 14.6; set 3 at 2-theta of 15.9, 16.6, 17.1 and 17.5.
A representative PXRD pattern of Form N is shown in figure 10. Form N displays the characteristic peaks of Family I. The sets of peaks of form N are similar to those of forms F, G, J and M, being set 1 at 2-theta of 11.2 to 11.6; set 2 at 2-theta of 13.9 to 15.0; and set 3 at 2-theta of 15.9 to 17.9, with the peaks may vary slightly in position, intensity and width due to mixing of variable proportion of isomorphs in Family I.
A representative PXRD pattern of form Q is shown in figure 30. Form Q displays peaks at 2-theta of 6.8, 8.4 and 20.2 degree.
A representative PXRD pattern of form R is shown in figure 31.Example 11: Single crystal X-ray analysis
Data were collected at room temperature using Bruker X-ray diffractometers equipped with copper radiation and graphite monochromators. Structures were solved using direct methods. The SHELXTL computer library provided by Bruker AXS, Inc facilitated all necessary crystallographic computations and molecular displays (SHELXTL TM Reference Manual, Version 5.1, Bruker AXS, Madison, Wisconsin, USA (1997)).Example 12: Calculation of PXRD pattern from single crystal data
To compare the results between a single crystal and a powder sample, a calculated powder pattern can be obtained from single crystal results. The XFOG and XPOW computer programs provided as part of the SHELXTL computer library were used to perform this calculation. Comparing the calculated powder pattern with the experimental powder pattern confirms whether a powder sample corresponds to an assigned single crystal structure (Table 9A). This procedure was performed on the crystal forms of azithromycin A, D, F, G, and J.
The calculated PXRD diffraction pattern of azithromycin form A is given in figure 1.
The calculated PXRD diffraction pattern of azithromycin form D is given in figure 5.
The calculated PXRD diffraction pattern of azithromycin form F is given in figure 9.
The calculated PXRD diffraction pattern of azithromycin form G is given in figure 12.
The calculated PXRD diffraction pattern of azithromycin form J is given in figure 15.
The results are displayed in the overlaid powder X-ray diffraction patterns for forms A, D, F, G, and J in figures 3, 7, 11, 14 and 17, respectively. The lower pattern corresponds to the calculated powder pattern (from single crystal results) and the upper pattern corresponds to a representative experimental powder pattern. A match between the two patterns indicated the agreement between powder sample and the corresponding single crystal structure.
Table 9A: Cacluated and Experimental PXRD Peaks of Isomorphs of Family IExample 13: Solid State NMR Analysis Solid State NMR analysis:
All 13 C solid state NMR spectra were collected on an 11.75 T spectrometer (Bruker Biospin, Inc. Billerica, MA), corresponding to 125 MHz 13 C frequency. The spectra were collected using a cross-polarization magic angle spinning (CPMAS) probe operating at ambient temperature and pressure. Depending on the quantity of sample analyzed, 7 mm BL or 4 mm BL Bruker probes were employed, accomodating 300 mg and 75 mg of sample with maximum speeds of 7 kHz and 15 kHz, respectively. Data were processed with an exponential line broadening function of 5.0 Hz. Proton decoupling of 65 kHz and 100 kHz were used with the 7mm and 4 mm probes, respectively. A sufficient number of acquisitions were averaged out to obtain adequate signal-to-noise ratios for all peaks. Typically, 600 scans were acquired with recycle delay of 3.0 s, corresponding approximately to a 30 minute total acquisition time. Magic angle was adjusted using KBr powder according to standard NMR vendor practices. The spectra were referenced relative to either the methyl resonace of hexamethylbenzen (HMB) at 17.3 ppm or the upfield resonance of adamantane (ADM) at 29.5 ppm. HMB referenced spectra show chemical shifts of all peaks shifted down field by 0.08 ppm with respect to same spectra referenced to ADM. The spectral window minimally included the spectra region from 190 to 0 ppm. The results are summarized in Table 10. Ss-NMR spectra for forms M, H and R were referenced to ADM. Ss-NMR spectra for forms A, D, G, F, J and N were referenced to HMB. Forms H and R were spun at a rate of 15 kHz.
The chemical shifts labeled in bold and underlined are the peaks or sets of peaks representative of each form. The chemical shifts labeled in italic are the solvent peaks that may be broad and variable (± 0.4ppm). The chemical shifts labeled with single asterisk may show splitting of < 0.3 ppm. The chemical shifts labeled with double asterisks may show variation of±0.3 ppm
The chemical shifts labeled in bold and underlined are the peaks or sets of peaks representative of each form. The chemical shifts labeled in italic are the solvent peaks that may be broad and variable (± 0.4ppm). The chemical shifts labeled with single asterisk may show splitting of < 0.3 ppm. The chemical shifts labeled with double asterisks may show variation of ± 0.3 ppm
The chemical shifts reported are accurate to within ± 0.2 ppm unless otherwise indicated.
A representative 13 C ssNMR spectrum of form A is shown in figure 21. Form A displays a peak at 178.1 ppm, and peaks at 104.1, 98.4, 84.6, 26.9, 13.2, 11.3 and 7.2 ppm.
A representative 13 C ssNMR spectrum of form D is shown in figure 22. Form D displays the highest chemical shift peak of 178.1 ppm and peaks at chemical shifts of 103.9, 95.1, 84.2, 10.6, 9.0 and 8.6 ppm.
A representative 13 C ssNMR spectrum of form F is shown in figure 23. Form F has two chemical shift peaks at approximately 179.1 ± 2 ppm, being 179.5 ppm and 178.6 ppm, and a set of 5 peaks at 10.1, 9.8, 9.3, 7.9, and 6.6 ppm, and ethanol peaks at 58.0±0.5 ppm and 17.2±0.5 ppm. The solvent peaks can be broad and relatively weak in intensity.
A representative 13 C ssNMR spectrum of form G is shown in figure 24. Form G has the highest chemical shift peak of 179.5 ppm, being a single peak with possible splitting of < 0.3 ppm and a set of 5 peaks at 10.4, 9.9, 9.3, 7.6, 6.5 ppm.
A representative 13 C ssNMR spectrum of form J is shown in figure 25. Form J has two chemical shift peaks at approximately 179.1 ± 2 ppm, those being 179.6 ppm and 178.4 ppm, a set of 4 peaks at 10.0, 9.3, 8.1 and 6.8 ppm and n-propanol peaks at 11.5±0.5 ppm and 25.2±0.5 ppm. The solvent peak can be broad and relatively weak in intensity.
A representative 13 C ssNMR spectrum of form M is shown in figure 26. Form M has one chemical shift peak at 179±1 ppm, being 179.6 ppm, peaks at 41.9, and 16.3 ppm, a set of 5 peaks at 10.3, 9.6, 9.3, 7.7 and 7.1 ppm and an isopropanol peak at 26.0± 0.5 ppm. The solvent peak can be broad and relatively weak in intensity.
A representative 13 C ssNMR spectrum of form N is shown in figure 27. Form N displays chemical shifts as a combination of isomorphs in Family J. The peaks may vary in chemical shift and in relative intensities and width due to the mixing of variable proportion of isomorphs contained in the form N crystalline solid solution.
A representative 13 C ssNMR spectrum of amorphous form is shown in figure 28. The amorphous azithromycin displays broad chemical shifts. The characteristic chemical shifts have the peak positions at 179 and 11 ± 0.5ppm.
A summary of the observed ssNMR peaks for forms A, D, F, G, H, J, M, N and R azithromycin is given in Table 10.Example 14: NMR Analysis of a Dosage Form
To demonstrate the ability of 13 C ssNMR to identify the form of azithromycin contained in a pharmaceutical dosage form, coated azithromycin tablets containing form G azithromycin were prepared and analyzed by 13 C ssNMR. Tablets were wet granulated and tabletted on an F-Press (Manesty, Liverpool, UK) using 0.262" x 0.531" tooling. Tablets were formulated and tabletted to contain 250 mg of form G azithromycin with a total tablet weight of 450 mg using the formula given below. The tablets were uniformly coated with pink Opadry II® (mixture of lactose monohydrate, hydroxypropylmethylcellulose, titanium dioxide, Drug & Cosmetic red # 30, and triacetin) (Colorcon, West Point, PA).
A coated tablet was gently crushed and the powdered sample was packed with a packing tool in solid state rotor containing no 13 C background. Analysis of the sample was performed under conditions outlined in Example 13.
A representative 13 C ssNMR spectrum of the tablet containing form G azithromycin is given in Figure 29.Example 15: Antimicrobial activity:
The activity of the crystal forms of the present invention against bacterial and protozoa pathogens is demonstrated by the compound's ability to inhibit growth of defined strains of human (Assay I) or animal (Assays II and III) pathogens.
Assay I, described below, employs conventional methodology and interpretation criteria and is designed to provide direction for chemical modifications that may lead to compounds that circumvent defined mechanisms of macrolide resistance. In Assay I, a panel of bacterial strains is assembled to include a variety of target pathogenic species, including representatives of macrolide resistance mechanisms that have been characterized. Use of this panel enables the chemical structure/activity relationship to be determined with respect to potency, spectrum of activity, and structural elements or modifications that may be necessary to obviate resistance mechanisms. Bacterial pathogens that comprise the screening panel are shown in the table below. In many cases, both the macrolide-susceptible parent strain and the macrolide-resistant strain derived from it are available to provide a more accurate assessment of the compound's ability to circumvent the resistance mechanism. Strains that contain the gene with the designation of ermA /ermB /ermC are resistant to macrolides, lincosamides, and streptogramin B antibiotics due to modifications (methylation) of 23S rRNA molecules by an Erm methylase, thereby generally prevent the binding of all three structural classes. Two types of macrolide efflux have been described; msrA encodes a component of an efflux system in staphylococci that prevents the entry of macrolides and streptogramins while mefA /E encodes a transmembrane protein that appears to efflux only macrolides. Inactivation of macrolide antibiotics can occur and can be mediated by either a phosphorylation of the 2'-hydroxyl (mph) or by cleavage of the macrocyclic lactone (esterase). The strains may be characterized using conventional polymerase chain reaction (PCR) technology and/or by sequencing the resistance determinant. The use of PCR technology in this application is described in J. Sutcliffe et al. "Detection Of Erythromycin-Resistant Determinants By PCR", Antimicrobial Agents and Chemotherapy, 40(11), 2562-2566 (1996). The assay is performed in microtiter trays and interpreted according to Performance Standards for Antimicrobial Disk Susceptibility Tests - Sixth Edition; Approved Standard, published by The National Committee for Clinical Laboratory Standards (NCCLS) guidelines; the minimum inhibitory concentration (MIC) is used to compare strains. The crystalline compound is initially dissolved in dimethylsulfoxide (DMSO) as 40 mg/ml stock solution.
Macrolide Resistance Mechanism(s)
Assay II is utilized to test for activity against Pasteurella multocida and Assay III is utilized to test for activity against Pasteurella haemolytica.
This assay is based on the liquid dilution method in microliter format. A single colony of P. multocida (strain 59A067) is inoculated into 5 ml of brain heart infusion (BHI) broth. The test compound is prepared by solubilizing 1 mg of the compound in 125 µl of dimethylsulfoxide (DMSO). Dilutions of the test compound are prepared using uninoculated BHI broth. The concentrations of the test compound used range from 200 µg/ml to 0.098 µg/ml by two-fold serial dilutions. The P. multocida inoculated BHI is diluted with uninoculated BHI broth to make a 10 4 cell suspension per 200 µl. The BHI cell suspensions are mixed with respective serial dilutions of the test compound, and incubated at 37°C for 18 hours. The minimum inhibitory concentration (MIC) is equal to the concentration of the compound exhibiting 100% inhibition of growth of P. multocida as determined by comparison with an uninoculated control.
This assay is based on the agar dilution method using a Steers Replicator. Two to five colonies isolated from an agar plate are inoculated into BHI broth and incubated overnight at 37°C with shaking (200 rpm). The next morning, 300 µl of the fully grown P. haemolytica preculture is inoculated into 3 ml of fresh BHI broth and is incubated at 37°C with shaking (200 rpm). The appropriate amounts of the test compounds are dissolved in ethanol and a series of two-fold serial dilutions are prepared. Two ml of the respective serial dilution is mixed with 18 ml of molten BHI agar and solidified. When the inoculated P. haemolytica culture reaches 0.5 McFarland standard density, about 5 µl of the P. haemolytica culture is inoculated onto BHI agar plates containing the various concentrations of the test compound using a Steers Replicator and incubated for 18 hours at 37°C. Initial concentrations of the test compound range from 100-200 µg/ml. The MIC is equal to the concentration of the test compound exhibiting 100% inhibition of growth of P. haemolytica as determined by comparison with an uninoculated control.
The invivo activity of the crystal forms of the present invention can be determined by conventional animal protection studies well known to those skilled in the art, usually carried out in mice.
Mice are allotted to cages (10 per cage) upon their arrival, and allowed to acclimate for a minimum of 48 hours before being used. Animals are inoculated with 0.5 ml of a 3 x 10 3 CFU/ml bacterial suspension (P. multocida strain 59A006) intraperitoneally. Each experiment has at least 3 non-medicated control groups including one infected with 0.1X challenge dose and two infected with 1X challenge dose; a 10X challenge data group may also be used. Generally, all mice in a given study can be challenged within 30-90 minutes, especially if a repeating syringe (such as a Cornwall@ syringe) is used to administer the challenge. Thirty minutes after challenging has begun, the first compound treatment is given. It may be necessary for a second person to begin compound dosing if all of the animals have not been challenged at the end of 30 minutes. The routes of administration are subcutaneous or oral doses. Subcutaneous doses are administered into the loose skin in the back of the neck whereas oral doses are given by means of a feeding needle. In both cases, a volume of 0.2 ml is used per mouse. Compounds are administered 30 minutes, 4 hours, and 24 hours after challenge. A control compound of known efficacy administered by the same route is included in each test. Animals are observed daily, and the number of survivors in each group is recorded. The P. multocida model monitoring continues for 96 hours (four days) post challenge.
The PD50 is a calculated dose at which the compound tested protects 50% of a group of mice from mortality due to the bacterial infection that would be lethal in the absence of drug treatment.
The crystal forms of the present invention (hereinafter "the active compound(s)"), may be administered through oral, parenteral, topical, or rectal routes in the treatment or prevention of bacterial or protozoa infections. In general, the active compound is most desirably administered in dosages ranging from about 0.2 mg per kg body weight per day (mg/kg/day) to about 200 mg/kg/day in single or divided doses (i.e. from 1 to 4 doses per day), although variations will necessarily occur depending upon the species, weight and condition of the subject being treated and the particular route of administration chosen. However, a dosage level that is in the range of about 2 mg/kg/day to about 50 mg/kg/day is most desirably employed. Variations may nevertheless occur depending upon the species of mammal, fish or bird being treated and its individual response to said medicament, as well as on the type of pharmaceutical formulation chosen and the time period and interval at which such administration is carried out. In some instances, dosage levels below the lower limit of the aforesaid range may be more than adequate, while in other cases still larger doses may be employed without causing any harmful side effects, provided that such larger doses are first divided into several small doses for administration throughout the day.
The active compound may be administered alone or in combination with pharmaceutically acceptable carriers or diluents by the routes previously indicated, and such administration may be carried out in single or multiple doses. More particularly, the active compound may be administered in a wide variety of different dosage forms, i.e. they may be combined with various pharmaceutically acceptable inert carriers in the form of tablets, capsules, lozenges, troches, hard candies, powders, sprays, creams, salves, suppositories, jellies, gels, pastes, lotions, ointments, sachets, powders for oral suspension, aqueous suspensions, injectable solutions, elixirs, syrups, and the like. Such carriers include solid diluents or fillers, sterile aqueous media and various non-toxic organic solvents, etc. Moreover, oral pharmaceutical compositions can be suitably sweetened and/or flavored. In general, the active compound is present in such dosage forms at concentration levels ranging from about 1.0% to about 70% by weight.
For oral administration, tablets containing various excipients such as microcrystalline cellulose, sodium citrate, calcium carbonate, dicalcium phosphate and glycine may be employed along with various disintegrants such as starch (and preferably corn, potato or tapioca starch), alginic acid and certain complex silicates, together with granulation binders like polyvinylpyrrolidone, sucrose, gelatin and acacia. Additionally, lubricating agents such as magnesium stearate, sodium lauryl sulfate and talc are often very useful for tabletting purposes. Solid compositions of a similar type may also be employed as fillers in gelatin capsules; preferred materials in this connection also include lactose or milk sugar as well as high molecular weight polyethylene glycols. When aqueous suspensions and/or elixirs are desired for oral administration, the active compound may be combined with various sweetening or flavoring agents, coloring matter or dyes, and, if so desired, emulsifying and/or suspending agents as well, together with such diluents as water, ethanol, propylene glycol, glycerin and various like combinations thereof.
For parenteral administration, solutions of the active compound in either sesame or peanut oil or in aqueous propylene glycol may be employed. The aqueous solutions should be suitably buffered (preferably pH greater than 8) if necessary and the liquid diluent first rendered isotonic. These aqueous solutions are suitable for intravenous injection purposes. The oily solutions are suitable for intraarticular, intramuscular and subcutaneous injection purposes. The preparation of all these solutions under sterile conditions is readily accomplished by standard pharmaceutical techniques will known to those skilled in the art.
Additionally, it is also possible to administer the active compound topically and this may be done by way of creams, jellies, gels, pastes, patches, ointments and the like, in accordance with standard pharmaceutical practice.
For administration to animals other than humans, such as cattle or domestic animals, the active compounds may be administered in the feed of the animals or orally as a drench composition.
The active compound may also be administered in the form of liposome delivery systems, such as small unilamellar vesicles, large unilamellar vesicles and multilamellar vesicles. Liposomes can be formed from a variety of phospholipids, such as cholesterol, stearylamine or phosphatidylcholines.