Preparation and characterization of enteric-coated delayed-release microsphere of phytosome loading allicin-rich extract

Abstract

Objective: Allicin, a natural organosulfur compound, is the main garlic ingredient, which has extensive pharmacological activities. Its unstable under acidic conditions due to alliinase's inactivation causes the need for preparations that delayed-release in the stomach to maximize allicin absorption. This study aimed to prepare and characterize the enteric-coated microsphere of phytosome loading allicin-rich extract to protect it from gastric acid. Methods: The allicin-rich extract phytosome (ArE-Ps) was prepared and evaluated for characteristics. Microsphere was made in three formulas with different molar ratios of ArE-Ps and Eudragit L30D-55 (1:1; 1:1.5 and 1:2) by spray dry. The three microspheres compared to particle size, entrapment efficiency, and dissolution test in acid and 7.4 pH medium. Results: Optimized ArE-Ps has a size of 251.6 nm, polydispersity index 0.466, zeta potential 34.11, entrapment efficiency of 62.62 %, and specific gravity of 1,005 g/ml. The surface topography of the three formulas shows an almost spherical shape with concave surfaces. The particle size of the microsphere ranges from 215±6.27 nm to 548.8±10.15 nm. Entrapment efficiency increases with an increasing number of polymers with a maximum value of 65.44 % at F3. The results dissolution test in vitro showed no drug release in acidic medium, and drug release occurred at a 7.4 pH medium. Drug release of three microsphere formulations followed the Korsmeyer-Peppas model with a k value of 12.7088±0.1769; 17.9322±1.5621; and 12.958±1.2677; respectively. Conclusion: Based on these results, the polymer's increase in three microsphere formulations can affect characteristics and retain drug release under acidic conditions.