Central composite design expert-supported development and validation of HPTLC method: Relevance in quantitative evaluation of protopine in Fumaria indica

The current study was executed for method development, validation and to estimate the concentration of protopine in methanolic extract of Fumaria indica by high-performance thin-layer chromatography (HPTLC). Isolation of bioactive compounds was carried out using the mobile phase, toluene:ethyl acetate:diethyl amine (8:2.5:0.5 v/v/v), and detected at wavelength 290 nm. This method was validated for precision, specificity, linearity, limit of detection (LOD), limit of quantification (LOQ), etc. The calibration range was found to be 500–5000 ng/spot for the bioactive compound. Protopine was separated with an R(f) value of 0.22 ± 0.03. The method was validated for linearity (r2 ≥ 0.996 ± 0.082), accuracy 98.75–102.12%), and RSD of precision (0.49–2.07) with a calibration curve range of 500.00–5000.00 ng/spot. The LOD and LOQ were found to be 83.92 ng/spot and 254.30 ng/spot., respectively. The Central Composite design expert was applied for the validation of robustness. Three independent variables such as the volume of toluene in solvent system, chamber saturation time and wavelength were investigated. The results indicated that a slight change in these variables had no significant effect on the peak response. This developed HPTLC method is simple, precise, robust, specific, rapid, and cost effective. It could be used for quality control study and quantification of protopine in the plant extract and different herbal formulations containing the plant species.