BETAMETHASONE SODIUM PHOSPHATE
Note: For more information refer to the post: Glucocorticoids, General information
A synthetic glucocorticoid, betamethasone is available as the base and as the dipropionate, acetate and sodium phosphate salts. The base is used for oral dosage forms. The sodium phosphate and acetate salts are used in injectable preparations. The dipropionate salt is used in topical formulations and in combination with the sodium phosphate salt in a veterinary-approved injectable preparation. Betamethasone may also be known as flubenisolone.
Betamethasone occurs as an odorless, white to practically white, crystalline powder. It is insoluble in water and practically insoluble in alcohol. The dipropionate salt occurs as a white or creamy-white, odorless powder. It is practically insoluble in water and sparingly soluble in alcohol. The sodium phosphate salt occurs as an odorless, white to practically white, hygroscopic powder. It is freely soluble in water and slightly soluble in alcohol.
Storage – Stability – Compatibility
Betamethasone tablets should be stored in well-closed containers at 2-30°C. The oral solution should be stored in well-closed containers, protected from light and kept at temperatures less than 40°C. The sodium phosphate injection should be protected from light and stored at room temperature (15-30°C); protect from freezing. The combination veterinary injectable product (Betasone®) should be stored between 2 – 30°C and protected from light or freezing.
When betamethasone sodium phosphate was mixed with heparin sodium, hydrocortisone sodium succinate, potassium chloride, vitamin B-complex with C, dextrose 5% in water (D5W), D5 in Ringer’s, D5 in lactated Ringer’s, Ringer’s lactate injection or normal saline, no physical incompatibility was noted immediately or after 4 hours.
For the product Betasone® (Schering), the manufacturer states that the drug is “contraindicated in animals with acute or chronic bacterial infections unless therapeutic doses of an effective antimicrobial agent are used.” See the monograph: Glucocorticoids, General Information for additional information.
In addition to the contraindications, precautions and adverse effects outlined in the opening section of glucocorticoids, betamethasone has been demonstrated to cause decreased sperm output and semen volume and increased percentages of abnormal sperm in dogs.
Doses for dogs:
For the control of pruritis:
a) Betasone® aqueous suspension: 0.25 – 0.5 ml per 20 pounds body weight IM. Dose dependent on severity of condition. May repeat when necessary. Relief averages 3 weeks in duration. Do not exceed more than 4 injections. (Package Insert; Betasone®-Schering)
Dosage Forms/Preparations/Approval Status/Withdrawal Times
Betamethasone diproprionate equivalent to 5 mg/ml of betamethasone and betamethasone sodium phosphate equivalent to 2 mg/ml betamethasone in 5 ml vials; Betasone® (Schering); (Rx) Approved for use in dogs.
Betamethasone valerate is also found in Gentocin® Otic, Gentocin® Topical Spray and Topagen® Ointment, all from Schering Animal Health.
Betamethasone sodium phosphate Injection 4 mg/ml (equivalent to 3 mg/ml betamethasone) in 5 ml vials; Celestone Phosphate® (Schering) (Rx); Cel-U-Jec® (Hauck); generic; (Rx)
Betamethasone sodium phosphate Injection 3 mg/ml and betamethasone acetate 3 mg/ml in 5 ml vials; Celestone Soluspan® (Schering); Generic (Rx)
Betamethasone oral solution 0.6 mg/5 ml andBetamethasone tablets 0.6 mg; Celestone® (Schering); (Rx)
Also many topical formulations available.