Optimization of stability indicating LC method for the sensitive in vitro determination from solid lipid nanoparticles and ex vivo analysis from rat skin of etofenamate

Abstract

Introduction: Etofenamate (2-(2-hydroxyethoxy) ethyl 2-[[3-(trifluoromethyl)phenyl]amino] benzoate) (ETO) is a yellowish viscous liquid which is a nonsteroidal anti-inflammatory drug (NSAID) that has been applied topically for joint and muscular pain and soft tissue disorders. Solid lipid nanoparticles (SLNs) are colloidal drug delivery systems prepared by non-irritant and nontoxic lipids that attract great interest because of their unique features. Semisolid SLNs are novel approach for dermal application of SLNs. Aims: The aim of this study was to show the development, validation, and application of a simple, selective and reliable RP-LC method that was extensively validated for its specificity and stability-indicating properties from its forced hydrolytic, oxidative, photolytic and thermal degradation products. Materials and Methods: In addition, the proposed method presented to application of ETO from rat skin extract in according to the United States Pharmacopeia and International Council on Harmonization Guidelines. For this reason, XSelect HSS T3 XP (150 x 4.6 mm ID x 2.5µm) (Waters Corp. Milford, MA, USA) analytical column was chosen for the best resolution. Mobile phase consisted of 0.1% H3PO4 in bidistilled water (pH adjusted to 7.0 with 5M NaOH) and acetonitrile in the ratio of (40:60, v/v) with the flow rate of 1 mL.min-1. The volume of the sample solutions was injected at 10µL and the detector was set up at 285 nm. The analysis was carried out at a temperature of 45oC. Coclusion: The developed stability indicating method presented low limit of detection, low limit of quantitation and good resolution between any of interferences from both commercial formulation and developed SLN formulation from rat skin, with symmetric, pure and perfect peak homogeneity. High percentage of recovery results shows that the proposed method is free from the interferences of the commonly used excipients and additives in the formulations of the commercial product or semisolid SLN formulations and also biological derivatives. © 2017 Bentham Science Publishers.