Design Expert-Supported Development and Validation of High-Performance Thin-Layer Chromatographic Stability-Indicating (HPTLC) Method: an Application in Quantitative Analysis of Ropinirole in the Bulk Drug and in Marketed Dosage Forms

A simple, precise and stability-indicating thin-layer chromatographic method for estimation of ropinirole HCl was developed and validated as per ICH guidelines. The mobile phase consisted of acetone–cyclohexane–6 M ammonia solution (8:5.5:0.5, v/v/v). Scanning the drug was done at 250 nm. Compact spots for ropinirole HCl were found at an Rf value of 0.51 ± 0.002. The linear regression analysis data for the calibration plots showed good linear relationship with R2 0.9976 ± 0.0011 in the working concentration range of 100–3,000 ng spot−1. The method was validated for precision, accuracy, ruggedness, robustness, specificity, recovery, limit of detection (LOD), and limit of quantitation (LOQ). The LOD and LOQ were 12.89 and 42.53 ng spot−1, respectively. The drug was subjected to degradation; the peaks of degradation products were well resolved from the standard with significantly different Rf values. Hence, this method can be used for quality control assay of ropinirole.