Stability of reserpine injections and tablets submitted by U.S. hospitals.

The stability of reserpine injections and tablets that had been stored in hospital pharmacies across the United States was studied. Through a voluntary FDA drug stability program, all hospital pharmacies in the United States were asked to complete a response card indicating information about the reserpine injections and tablets they had in stock. Based on the responses, FDA selected 93 samples of reserpine injections and 51 samples of reserpine tablets. The samples of injections were subjected to tests for identification, pH, presence of other alkaloids, presence of 3,4-dehydroreserpine, and strength. All samples of reserpine injections met USP requirements. Two samples of reserpine tablets representing one lot each from two manufacturers failed to meet USP requirements for content uniformity. Reserpine injections and tablets appear to be stable under actual marketplace conditions.

Stability of nitroglycerin tablets submitted by U.S. hospitals.

The stability of nitroglycerin tablets that had been stored in hospitals across the United States was studied. Through a voluntary FDA drug stability program, all hospital pharmacies in the United States were asked in October 1981 to complete a response card indicating information about nitroglycerin tablets they had in stock. Based on the responses, FDA selected 167 samples (representing three manufacturers and all available tablet strengths) from pharmacies that represented an adequate cross section of the country. The samples were analyzed for content uniformity, strength, identification, and disintegration; samples that left a residue on the screen of the tablet disintegration basket were tested for dissolution by three methods and compared with samples that did not leave a residue. All samples met USP requirements for content uniformity, strength, and disintegration. Six samples that showed unusual disintegration characteristics dissolved slowly by one or more methods; however, other samples also showed slow dissolution. Nitroglycerin tablets appear to be stable when stored under actual marketplace conditions. The USP disintegration test will not distinguish between rapidly and slowly dissolving tablets.

Stability of sterile dexamethasone acetate suspensions and dexamethasone sodium phosphate injections submitted by U.S. hospitals.

The stability of sterile dexamethasone acetate suspensions and dexamethasone sodium phosphate injections that had been stored in hospital pharmacies across the United States was studied. Through a voluntary FDA drug stability program, all hospital pharmacies in the United States were asked in October 1981 to complete a response card indicating information about the sterile dexamethasone acetate suspensions and dexamethasone sodium phosphate injections they had in stock. Based on the responses, FDA selected 21 samples of sterile dexamethasone acetate suspensions (representing two manufacturers) and 114 samples of dexamethasone sodium phosphate injection (representing 11 manufacturers). These samples were analyzed for identification, pH, and strength. All samples of sterile dexamethasone acetate suspension met USP requirements. Eleven samples of dexamethasone sodium phosphate injection representing 10 lots from three manufacturers failed USP assay requirements for strength. All samples that failed to meet strength requirements showed evidence of degradation by oxidation. Sterile dexamethasone acetate suspensions appear to be stable when stored under actual marketplace conditions, but there is a problem with the shelf-life stability of dexamethasone sodium phosphate injections made by some manufacturers.

Stability of digitoxin tablets submitted by U.S. hospitals.

The stability of digitoxin tablets that had been stored in hospital pharmacies across the United States was studied. Through a voluntary FDA drug stability program, all hospital pharmacies in the United States were asked in October 1981 to complete a response card indicating information about the digitoxin products they had in stock. Based on the responses, FDA selected 25 samples (representing seven manufacturers) from pharmacies that represented an adequate cross section of the country. These samples were analyzed for content uniformity, strength, dissolution, identification, and other digitoxosides. Of the 25 samples, 19 lots were represented, including 11, 6, 1, and 1 lots of 0.1-mg, 0.2-mg, 0.15-mg and 0.05-mg tablets, respectively. Samples from two lots failed to meet USP requirements for strength, content uniformity, and dissolution; samples from four lots failed to meet the requirements for dissolution only. All six defective lots did not show an expiration date, indicating that they were manufactured before 1975. Digitoxin tablet products still within the expiration date showed no evidence of degradation after storage under actual marketplace conditions.