Preparation and evaluation of lipid matrix microencapsulation for drug delivery of azilsartan kamedoxomil

The aim of the work is to consolidate azilsartan-kamedoxomil (AZM) into lipid matrix controlled-release microparticles to enhance its permeability because AZM belongs to Biopharmaceutical classification (BCS) IV which characterized by poor permeability and to protect AZM from light and humidity and execute a prolonged release profile. Materials and methods. A reversed-phase HPLC method was created and validated to estimate the drug. AZM microparticles formulations were invented using melt dispersion technique and waxy materials such as carnuba wax, beeswax, stearic acid in the ratio of waxy-substance: drug ranging from 0.25: 1 to 1:1 and stabilizer namely; tween 80 and Poloxamer 407 in ratio of stabilizer: drug ranging from 0.5:1 to 1:1. Azilsartan formulations were assessed for azilsartan-medoxomil content, loading, entrapment efficiency, the zeta potential,the particle size, the morphology by scanning electronic microscopy (SEM), and in-vitro release profile. Results. Zeta potential results for microparticle formulations using beeswax and carnuba range from -21.1 mV to -26.6 mV and -20.6 mV to -26.7 mV, respectively. This difference indicates that the azilsartan microparticles containing stearic acid are better stabilized with zeta potential of 25.3 - 29.7 mV. Furthermore, the release from azilsartan microparticle formulations containing stearic acid exceeded 80 % after 8 h and remained for 24 h while release from beeswax did not exceed 65 % after the same period and less than 60 % in case of carnuba formulations Conclusions. The formulation (AZSP4) exhibited the highest zeta potential and released exceeding 80 % of AZM over the course of 8 hours and remained over a day. AZSP4 microparticles formulation containing, poloxamer 407, in a 0.8:0.8:1 drug: stearic acid: poloxamer ratio proved the ability of stearic acid microencapsulation employing poloxamer as stabilizer in a certain ratio can prolong the release of AZM