Analytical Method Development and Validation for the Simultaneous Estimation of Risperidone and Trihexyphenidyl Hydrochloride by Using RP-HPLC method

Relangi Karun Kumar^1*, Gope Edward Raju², Kandregula Uma Maheswari³, Doonaboyina Raghava⁴, Kavala Nageswara Rao⁵
Department of Pharmaceutical Analysis, K.G.R.L College of Pharmacy, Bhimavaram-534201, A.P, India

Abstract
A new method was established for simultaneous estimation of Risperidone and Trihexyphenidyl hydrochloride by RP-HPLC method. The chromatographic conditions were successfully developed for the separation of Risperidone and Trihexyphenidyl hydrochloride by using ThermosilC18 column (4.0×125mm) 5µ, flow rate was 1ml/min, mobile phase ratio was (70:30 v/v) methanol: Sodium acetate buffer pH 3 (pH was adjusted with orthophosphoricacid), detection wavelength was 252nm. HPLC instrument is Shimadzu, model No. SPD-20MA LC+20AD, Software- LC-20 Solution. The retention times were found to be 2.566mins and 3.417mins. The % purity of Risperidone and Trihexyphenidyl hydrochloride was found to be 101.04% and 99.24% respectively. The system suitability parameters for Risperidone and Trihexyphenidyl hydrochloride such as theoretical plates and tailing factor were found to be 4668, 1.3 and 6089 and 1.2, the resolution was found to be 6.0. The analytical method was validated according to ICH guidelines (ICH, Q2 (R1)). The linearity study Risperidone and Trihexyphenidyl hydrochloride was found in concentration range of 5µg-25µg and 50µg-250µg and correlation coefficient (r²) was found to be 0.999 and 0.999, % recovery was found to be 99.56% and 99.48%, %RSD for repeatability was 0.86 and 0.82, % RSD for intermediate precision was 0.44 and 0.19 respectively. The precision study was precise, robust, and repeatable. LOD value was 3.17 and 5.68, and LOQ value was 0.0172 and 0.2125 respectively. Hence the suggested RP-HPLC
Keywords: ThermosilC18 column, Risperidone and Trihexyphenidyl hydrochloride, RP-HPLC