Simple, Sensitive and Stability Indicating High Performance Liquid Chromatographic Assay of Terbinafine Hydrochloride in Dosage forms

Terbinafine hydrochloride (TFH), is a potent antifungal agent of the allylamine class with broad spectrum activity against yeasts, dimorphic fungi, molds, and dermatophytes. A new, simple, rapid, selective, precise, accurate, and stability indicating high performance liquid chromatographic method has been developed for the determination of terbinafine hydrochloride (TFH) in pharmaceuticals. The assay was performed using an Zorbax Eclips XDB C-18 (3.5 µm, 4.6 × 150 mm i.d.,) column at 30ºC temperature with UV-detection at 222 nm. A mobile phase consisting of buffer (1000 mL water, 2 mL triethylamine, pH 3.4 adjusted with trifluoroacetic acid.), isopropyl alcohol and methanol (40:12:48, v/v/v), was used in the assay at a flow rate of 1 mL min-1. The method was validated and system suitability parameters were investigated. An excellent linearity was obtained over the concentration range 1 - 80 μg mL-1 TFH with limits of detection (LOD) and quantification (LOQ) values of 0.3 and 1.0 mg mL-1, respectively. The proposed method were applied successfully to the determination of TFH in tablets. The results obtained were in good agreement with those obtained by a reference method, with high precision and without any detectable interference from tablets excipients. The validity and reliability of the proposed methods were further assessed by the recovery studies via a standard addition method. In addition, forced degradation of TFH was conducted in accordance with the ICH guidelines. Acidic, basic water hydrolysis, thermal stress, peroxide and photolytic degradation were used to assess the stability indicating power of the method. Slight degradation was observed during oxidative degradation and no degradation was observed under other stress conditions.