Preparation and Characterization of Crosslinked Gum Acacia Microspheres by Single Step Emulsion In-Situ Polymer Crosslinking Method: A Potential Vehicle for Controlled Drug Delivery
Because of its biodegradability several natural polymers, such as plant polysaccharides, have been proposed as appropriate excipients for the development of controlled drug delivery systems for oral administration. In this work microspheres of crossinked gum acacia were prepared by single step emulsion crosslinking method using glutaraldehyde (GL) as the crosslinking agent and Hydrochloric acid (HCl) as the catalyst.. Aqueous gum acacia solution (10% w/v) was emulsified with castor oil using span 80 as emulsifier (3%) and reacted with GL (25% solution) at different temperature. After a certain time of reaction the mixture was cooled and the oily phase decanted. The microspheres were washed with isopropyl alcohol (IPA) and dried at 40OC to constant weight. The FTIR spectra and the swelling properties of obtained microspheres showed that gum acacia could be crosslinked using glutaraldehyde. Degree of swelling and % weight loss decreased with increase in amount of GL and severity of reaction conditions (temperature and time). Crosslinking with higher amount of glutaraldehyde produced microspheres with lower swelling degree. These results lead to the conclusion that crosslinked GA presents good perspectives for its use in modified release pharmaceutical formulations.
Parul K Patel and Pandya SS