Abstract

DEVELOPMENT AND VALIDATION OF STABILITY INDICATING RP-HPLC AND SPECTROPHOTOMETRY FOR SIMULTANEOUS ESTIMATION OF SILDENAFIL CITRATE AND FLUOXETINE IN BULK & TABLET DOSAGE FORM.

Anjani Chaudhari, Bhargav Patel and Rajashree Mashru*

Abstract

A simple, precise, sensitive and reproducible, rapid stability indicating RP-HPLC method for the simultaneous estimation of Sildenafil citrate and Fluoxetine HCl by forced degradation studies has been developed. The developed method separates degradation products. Sildenafil citrate and Fluoxetine and their combination drug product were exposed to acid, base, oxidation, thermal and photostability conditions. The proposed HPLC method utilizes the Shimadzu HPLC, Chrome Budget C18 Column (particle Size 5μm: 250 mm × 4.6 mm internal daimeter,5μm particle size using mobile phase consisting of Acetonitrile : Potassium Dihydrogen Phosphate buffer with 30 mM Triethylamine pH adjusted to 6 with o-phosphoric acid: Methanol (60:30:10 v/v) in a gradiant at the flow rate of 1 ml/min, with a load of 20μL. The detection was carried out at 230 nm. The retention time of Sildenafil citrate and Fluoxetine was found to be around 7.23 min and 9.33 min, respectively. The number of theoretical plates and tailing factor for Sildenafil citrate and Fluoxetine were NLT 3000 and should NMT 2 respectively. The proposed method was validated according to ICH guidelines and the results were found to be within the acceptable range. Hence, the proposed method can be used for the routine quality control of the drugs and can also be applied to pharmacokinetic studies. UV spectrophotometric methods namely 1) Absorption factor method (AFM) 2) Dual wavelength method 3) "zero-crossing"first derivative spectrophotometry were developed and validated for the quantitative determination of Sildenafil citrate (SC) and Fluoxetine hydrochloride (FT). Different analytical performance parameters such as linearity, precision, accuracy, specificity, limit of detection (LOD) and limit of quantification (LOQ) were determined according to International Conference on Harmonization ICH Q2B guidelines.

Keywords: Sildenafil citrate[SC], Fluoxetine[FT], Reverse phase HPLC, Validation, stability indicating methods.