Stability of extemporaneously compounded spironolactone suspensions.

The short-term stability of spironolactone in liquid formulations prepared from spironolactone tablets was studied at three temperatures. Suspensions of spironolactone at concentrations of 2.5, 5.0, and 10.0 mg/mL were prepared by grinding film-coated tablets to a fine powder, adding Purified Water, USP, triturating the mixture to form a fine paste, adding Cherry Syrup, NF, and homogenizing the suspension. Drug concentrations were immediately measured by a stability-indicating high-performance liquid chromatographic (HPLC) method. Samples were stored in amber glass prescription bottles at 5 and 30 degrees C in controlled environmental cabinets and at ambient room temperature (20 to 24 degrees C) under intense fluorescent light. After two and four weeks of storage the bottles were shaken, and samples were removed and assayed by HPLC. There was no appreciable loss of spironolactone from the cherry syrup formulations stored for two weeks under the conditions studied. Degradation was less than 5% for samples stored for four weeks. Color and odor of the samples did not change appreciably, and counts of bacteria and fungi remained within acceptable limits. Extemporaneously prepared suspensions of spironolactone in Cherry Syrup, NF, are stable for four weeks under the conditions studied.