Microencapsulation of Andrographis paniculata with water-soluble biopolymers

Abstract

Andrographis paniculata Nees. is widely used as traditional Thai medicine for the treatment of diarrhea in baby pigs. Due to the high bitterness taste, the baby pigs were not able to consume it. Microencapsulation is one of the methods that can help solving this problem. The aim of this research work is to study the microencapsulation of Andrographis paniculata Nees. by a complex coacervation technique. The effects of negative charge polymer, gelatin to negative charge polymer ratio, core to wall ratio, hardening time and amount of hardening agent on the properties of the microcapsules were investigated. The results showed that microcapsules could be prepared when acacia was used as negative charge polymer. The optimum condition, which provided grey and powder-like microcapsules and a high percentage of yield and drug entrapped were 50:50 gelatin to acacia ratio, 1:2 core to wall ratio, 120 minutes of hardening time and 5 ml of formaldehyde solution as a hardening agent. The mean size of microcapsules from all formulations was 50 micrometers. The higher the core to wall ratio, the greater the drug release rate. This was because the higher core to wall ratio yielded a thinner film coating of polymer. The stability study indicated that andrographolide in the microcapsule without light protection degraded faster than those protected from light.