API-ammonium ionic liquid – Polymer compounds as a potential tool for delivery systems

Abstract

The objective of the present study was to synthesized a novel drug delivery system based on ammonium ionic liquid containing active pharmaceutical ingredients (API) grafted–Poly(L-lactide) (API-IL-PLA). Sparingly water soluble mefenamic acid (MEF) was used as a model drug for the studying of drug loading efficiency and drug release performance. The synthesis of two mefenamic acid (MEF)-ionic liquid compounds composed of MEF in an anionic form and ammonium cation (choline, MEF1), or {di(2-hydroxyethyl)dimethyl ammonium} (MEF2) were presented. The synthesized compounds of MEF1 and MEF2 were used as initiator for ring opening polymerization (ROP) of lactide (LA) with stannous octoate (SnOct2) as a catalyst. The effect of temperature, SnOct2:LA, and MEF:LA ratios on the polymerization process were examined. The PMEF1 and PMEF2 were used for formulation of nanoparticles (NPs) by emulsion-solvent evaporation technique. NPs have spherical shapes and controlled sizes of 330nm to 569nm with high encapsulation efficiency up to 94%. Solid NPs were evaluated for in vitro release in phosphate–buffered saline (pH=7.4) by using dialysis bags at temperature 37°C. Both NPs have shown controlled and sustained release up to 72h and 264h, respectively. The obtained data from drug release profile were characterized by different drug release models and they were fitted with pseudo second order kinetics model with high correlation coefficient (R2=0.999).