Development and validation of simple HPTLC – UV assay method for determination of quetiapine fumarate concentrations in simulated plasma fluid

Background: Quetiapine fumarate (QTF) is a high-affinity monoaminergic antagonist selective for serotonin Type 2 (5HT2) and dopamine Type 2 (D2) receptors. In this paper, we formulated and validated a simple, reproducible, and convenient procedure for determining QTF concentration in Simulated Plasma Fluid using HPTLC-UV. Methodology: Simulated plasma samples do not require deproteinization. A simulated plasma fluid sample was prepared using a one-step filtration method with a 0.45 µm nylon syringe filter. HPTLC chromatographic separation of test plasma samples was achieved by TLC silica gel aluminium plates 60 F254, which served as the stationary phase. Results and Discussion: The mobile phase consisted of a mixture of methanol and acetonitrile (3:7 v/v), followed by densitometric detection at 296 nm. Well, separated peaks have been noted with retardation factors (Rf) of 0.62. Calibration plots were found to be highly linear (Correlation coefficient r²> 0.99) in the concentration interval of 20–120 ng/mL. Inter and intraday assay precision and accuracy were below 2%. The proposed method avoided the use of a buffer and employed low volumes of simulated plasma samples with plain mobile phase composition. Conclusion: The developed HPTLC–UV assay method was found to be simple, accurate, and reproducible for determining Quetiapine Fumarate in simulated plasma fluid. Validation results confirmed the method's specificity, linearity, precision, and robustness as per ICH guidelines. This method can be effectively applied in routine bioanalytical studies and drug monitoring.