Microencapsulation of amoxycillin trihydrate by complex coacervation and spray-drying techniques

Abstract

In this study, amoxyillin microcapsules were prepared by 2 methods, complex coacervation and spray-drying techniques. The complex coacervation used two types of polymer to form wall i.e., gelatin-acacia and gelatin-SCMC. In the spray-drying technique polyvinyl acetate (Kollicoat SR30D) was used as a polymer to form wall. In addition, the factors of core to wall ratio, pH, concentration of wall and stirring rate on the preparation of amoxycillin microcapsules by complex coacervation were investigated from the percent yield, drug content, core entrapment, size, size distribution, shape, surface area and drug release profile characteristics. In spray-drying technique the factors of core to wall ratio, inlet air temperature, feed rate and solid content were also investigated in the same way. It was found that gelatin-acacia complex coacervation with 1:2 core to wall ratio of 2% concentration of wall prepared at pH 3.5 with 700 rpm of stirring rate provided high percent yield of 88%, higher drug content, higher core entrapment and lower release profile than gelatin-SCMC as a wall. The release of amoxycillin from gelatin-acacia walled microcapsules was 57.82% in 2 hours at pH 1.2 and 100% in 12 hours at pH 6.8. Whereas in spray-drying technique, microcapsules prepared with 1:2 core to wall ratio, inlet air temperature of 120ํC, feed rate of 24 mL/min and solid ontent of 10% provided percent yield of 60% with free-flowing properties but the release of amoxycillin in pH 6.8 was the lowest. It demonstrated that 93.09% of amoxyillin was released within 12 hours.