K.V. Lalitha*1, R. Kiranjyothi2
1Department of Pharmaceutical Analysis, Raghavendra Institute of Pharmaceutical Education and Research, Ananthapuramu – 515001, Andhra Pradesh, India.
2Department of Pharmaceutical Analysis, JNTUA – Oil Technological Research Institute, Ananthapuramu – 515001, Andhra Pradesh, India.
A B S T R A C T
A novel stability indicating RP-HPLC method was developed for the estimation of Phentermine hydrochloride in tablet dosage form. The separation was achieved on C18 (250 mm x 4.6 mm x 5 µm) column using a mobile phase composition of 0.2% Triethyl amine in water (pH- 3.5 with OPA) and methanol (70:30 % V/V). Eluents were detected at 210 nm at 1 ml/min. Stress studies were performed with milder conditions followed by stronger conditions so as to get sufficient degradation around 20%. A total of three degradation products were detected and separated from analyte. The linearity of the proposed method was investigated in the range of 25 – 175 µg/ml for Phentermine. The limit of detection and limit of quantification was found to be 1.89µg/ml and 5.67µg/ml respectively. Precision % RSD was found to be less than 2% and the mean recovery was between 99-101%. The method was validated according to ICH guidelines
Keywords: Phentermine hydrochloride, RP-HPLC method, Stress degradation, ICH guidelines