Comparative RP-HPLC Analytical Method Validation of Thiocolchicoside in Parenteral Dosage Forms: Influence of Protic and Aprotic Solvents

Abstract

The present study aims to develop and validate a robust, precise, and reproducible reverse-phase high-performance liquid chromatography (RP-HPLC) method for the quantitative determination of Thiocolchicoside in various parenteral formulations, with a comparative assessment of protic and aprotic solvents used during method optimization. Thiocolchicoside, a semi-synthetic muscle relaxant, is widely used in injectable dosage forms for the treatment of musculoskeletal disorders. The analytical method was validated in accordance with ICH Q2(R1) guidelines, evaluating critical parameters such as specificity, linearity, accuracy, precision, limit of detection (LOD), limit of quantitation (LOQ), robustness, and system suitability. Two solvent systems—one based on protic solvents (e.g., methanol, ethanol) and the other on aprotic solvents (e.g., acetonitrile, dimethylformamide)—were employed to investigate their influence on chromatographic performance and analyte stability. Comparative analysis revealed that aprotic solvent systems provided superior peak resolution, reduced tailing factor, and enhanced method sensitivity, while protic solvents demonstrated better solubility and sample compatibility for routine analysis. This study highlights the critical role of solvent selection in RP-HPLC method development and offers an optimized, validated analytical approach for the reliable estimation of Thiocolchicoside in injectable dosage forms.