UPLC–MS/MS Method Development for Simultaneous Estimation of Diclofenac and Resveratrol-Loaded Liposomal Gel Formulation in Mice Skin Model: Application to Dermatokinetic Study

Abstract The current research work describes the development of a simple, fast, sensitive and efficient bioanalytical UPLC/MS–MS method for the simultaneous estimation of diclofenac and resveratrol in mice skin samples. Quetiapine was used as an internal standard (IS). Analytical separation was performed on ACQUITY UPLC C18 Column (2.1 × 100 mm; 1.7 μm) using ammonium acetate (5 mM) in water and methanol (B) with isocratic elution at ratio of (50, 50 v/v) and flow rate of 0.4 mL/min. The duration of separation was maintained for 3 min. Electrospray ionization mass spectrometry in a positive and negative ionization mode was used for detection. Selective ion mode monitoring was used for the quantification of m/z 296.025> 249.93 for diclofenac, m/z 229.09 > 143.03 for resveratrol and MRM/ES+ve mode applied in m/z 384.25> 253.189 for IS transitions from parent to daughter ion. The lower detection and quantification limits were accomplished, and precision (repeatability and intermediate precision) with a coefficient of variation below 10% produced satisfactory results. The developed bioanalytical method was found to be useful for its suitability for the dermatokinetic evaluation of treatments through rat skin. Improvement in AUC (1.58-fold for diclofenac and 1.60-fold for resveratrol) and t1/2 in the dermis (2.13 for diclofenac and 2.21-fold for resveratrol) followed by epidermis was observed for diclofenac and resveratrol-loaded liposomal gel formulation over the conventional gel. Overall, the developed method for the dermatokinetic studies of the above-mentioned dual drugs-loaded liposome gel was found to be reproducible and effective for bioanalytical.