The stability of furosemide, nadolol, and propranolol hydrochloride in extemporaneously compounded single-dose powder packets was studied. The powders prepared from crushing and triturating commercial tablets with acetylcysteine granules, lactose powder, or lactofermin tablets were divided and packed into single doses using a packing system in the hospital pharmacy. The packets were stored under ambient conditions, and samples were removed at 0, 1, 2, 3, and 4 weeks for assay of drug concentrations by stability-indicating high-performance liquid chromatography. The results demonstrated that the concentration of nadolol in the samples with any of the three diluents remained within 90 % of initial concentration throughout the study period under storage conditions. Furosemide and propranolol hydrochloride were stable for up to 4 weeks (more than 90 % of initial concentration remaining) with lactose or lactofermin tablets employed as diluents but, furosemide was stable with acetylcysteine granules for only 7 days, and less than 90 % initial concentration of propranolol hydrochloride remained in the powders following one week of storage. In addition, the packing process significantly reduced the drug concentrations in both furosemide and propranolol hydrochloride powders diluted with acetylcysteine granules. The acidic nature and ingredients in acetylcysteine granules may have accelerated the degradation of both furosemide and propranolol hydrochloride. It is therefore recommended that acetyl cysteine granules should be avoided in the extemporaneous compounding of pediatric powders for both drugs.
