STABILITY OF SPIRONOLACTONE IN AN EXTEMPORANEOUSLY PREPARED SUSPENSION AT 2 TEMPERATURES

OBJECTIVE: To determine the stability of spironolactone in an extempor aneously prepared suspension at 22 and 4-degrees-C over a three-month storage period. DESIGN: Spironolactone suspension (1 mg/mL) was prepar ed in syrup NF, carboxymethylcellulose, and purified water USP. The su spension was stored in ten amber glass prescription bottles; five were stored at 22-degrees-C and five at 4-degrees-C. Samples were drawn fr om each bottle and analyzed in duplicate (n = 10) on days 0, 7, 14, 28 , 42, 56, 70, and 91. Spironolactone concentrations were measured by a reproducible arid stability-indicating HPLC method. Inspection of vis ual and pH changes also was performed on each study day. RESULTS: The mean concentration of spironolactone was always higher than 98 percent of its initial concentration. The pH and appearance of the suspension did not change substantially. CONCLUSIONS: Spironolactone was stable in a suspension containing syrup, carboxymethylcellulose, and purified water for three months during storage in amber glass bottles at both 22 and 4-degrees-C.