Stability of digoxin tablets collected from U.S. hospitals.

The stability of digoxin tablets that had been stored in hospitals across the United States was studied. All hospital pharmacies in the U.S. were contacted in February 1980 to inform them about the program, the reimbursement procedures, the sampling requirement, and the process by which laboratory results would be distributed. A response card was included for those who wanted to participate. Ninety-two samples, representing three manufacturers and an adequate cross-section of the country, as well as typical dosage forms and packaging variations, were selected for laboratory analyses of content uniformity, strength, dissolution, identification, and related fluorescing substances. Eighty-five samples met the current compendial standards and seven samples failed the dissolution specifications. All seven were manufactured before July 1975 when the UPS dissolution requirements were changed. The digoxin products studied were not adversely affected by the variable stresses of the marketplace.