UV spectrophotometry and nonaqueous determination of terbinafine hydrochloride in dosage forms.

An ultraviolet spectrophotometric and a nonaqueous volumetric method for determining terbinafine hydrochloride (TH) in pharmaceutical formulations are presented. The UV spectrophotometric procedure was developed for assay of TH in raw materials, tablets, and creams. The method was tested for linearity (0.8-2.8 micrograms/mL, r = 0.9997), recovery (102.00% for creams and 99.90% for tablets) and precision (101.3%, CV = 0.96%, n = 9, for creams; 100.25%, CV = 1.08%, n = 9, for tablets). The volumetric method involves titration of TH with 0.05M perchloric acid with crystal violet as indicator. This method was used for quantitative determination of TH in raw materials and tablets. Mean recovery and precision were, respectively, 100.41 and 101.18% (CV = 1.64%, n = 9) for TH tablets. There were no significant differences between the proposed methods and a previously described high-performance liquid chromatographic method. The UV spectrophotometric and titrimetric methods are potentially useful for a routine laboratory because of their simplicity, rapidity, and accuracy.