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