title: Stability of pilocarpine hydrochloride and pilocarpine nitrate ophthalmic solutions submitted by U.S. hospitals.
abstract: The stability of pilocarpine hydrochloride and pilocarpine nitrate ophthalmic solutions stored in hospital pharmacies across the United States was studied. Through a voluntary drug stability program, FDA selected 252 samples (representing 11 manufacturers) from pharmacies representing an adequate cross section of the country. The samples were analyzed for strength, identification, pH, and isopilocarpine and pilocarpic acid impurities. All samples of pilocarpine nitrate met USP requirements. Eight samples of pilocarpine hydrochloride had tablets that exceeded the USP upper limit for strength. All of these samples were in 1- and 2-mL bottles. The amount of isopilocarpine found ranged from 1 to 6.4%, and the amount of pilocarpic acid from 1.5 to 10.1%. Although pilocarpine salts in ophthalmic solution decompose into isopilocarpine and pilocarpic acid under various conditions of storage, an amount of pilocarpine is maintained that is within the compendial limits. However, there is a problem of evaporation from some of the 1- and 2-mL containers in which this product is supplied.
mesh_terms: D004340:Drug Contamination / Q000032:analysis; D004355:Drug Stability; D006863:Hydrogen-Ion Concentration; D009883:Ophthalmic Solutions; D010607:Pharmacy Service, Hospital; D010862:Pilocarpine / Q000032:analysis* / Q000592:standards; D014481:United States; D014486:United States Food and Drug Administration
chemical_list: D009883:Ophthalmic Solutions; D010862:Pilocarpine