I I n n t t e e r r n n a a t t i i o o n n a a l l J J o o u u r r n n a a l l o o f f P P h h a a r r m ma a S S c c i i e e n n c c e e s s Vol. 6, No. 3 (2016): 1524-1533 Research Article Open Access ISSN: 2320-6810 Study of olive oil-loaded chitosan/carrageenan coacervate and its antibacterial property Chayanika Deka 1 , Manali Dutta 2 , Deepanwita Deka 3 , Dhruva Kumar Jha 3 and Dilip Kumar Kakati 1 * 1 Department of Chemistry, Gauhati University, Guwahati-781014, Assam, India. 2 Department of Chemical Sciences, Tezpur University, Napaam-784028, Assam, India. 3 Microbial Ecology Laboratory, Department of Botany, Gauhati University, Guwahati-781014, Assam, India. * Corresponding author: Dilip Kumar Kakati, e-mail: dilip_kakati2003@yahoo.co.in ABSTRACT The present study aims at synthesizing olive oil loaded chitosan/carrageenan polyelectrolyte complex by complex coacervation method. The formation of complex was found to be dependent on pH, ratio between chitosan and carrageenan and the amount of crosslinker, glutaraldehyde. The swelling and release studies were carried out in buffer solutions of pH 4, 7, 9 and phosphate buffered saline system (pH=7.4). The prepared coacervates were characterized by FTIR, TGA and SEM. The olive oil-loaded coacervate was also tested for antimicrobial activity against Proteus mirabilis, Enterobacter aerogenes, Bacillus subtilis and Staphylococcus aureus. The loaded coacervate was found to be active against B. subtilis and P. mirabilis. The zone of inhibition was 6.5±0.5 mm against B. subtilis and 11±0 mm against P. mirabilis. However, no antibacterial activity was observed against the other two strains of bacteria. Keywords: carrageenan; chitosan; controlled release; olive oil; polymeric drug delivery system. 1. INTRODUCTION Polymers are being increasingly used in carrier systems for drugs and other bioactive molecules [1-6]. The use of polymers serves several objectives. The basic purpose is to modify the release behavior of the drugs. Polymers can provide a matrix for the enclosure of the drug or form a membrane around the drug and thereby sustains its controlled release over a prolonged period, avoiding repetitive dosing of the drug. Moreover, by controlled release, it minimizes the side effects of the drug and thereby protects the stomach lining from aggressive drugs. Further, the polymers can also contribute to enhancing the stability of the drug by protecting it from action of other molecules and macromolecules like proteins. Because such interactions can alter the chemical structure of the active ingredient; leading to loss of pharmaceutical action. Among the polymers used as carriers, natural polymers are preferred over synthetic ones, due to their biodegradable, biocompatible and non-toxic nature. Further, as the release of the drugs usually occurs either by diffusion through the polymer or by degradation of the polymer or by disorganization of the supramolecular structure of the carrier, synthetic polymers are not favored as they may produce harmful degradation products. Polysaccharides, polypeptides and phospholipids are mostly used as the carrier for drugs and bioactive materials. Complex coacervation is a simple and easy technique for the development of a polymeric carrier for drugs and other bioactive materials. In this technique a polymeric complex is produced by interaction between a cationic polymer and an anionic polymer. Among the polysaccharides two such important cationic and anionic polymers are chitosan and carrageenan respectively. Chitosan is a linear polysaccharide composed of randomly distributed β-(1-4)-linked D- glucosamine (deacetylated unit) and N-acetyl-D- glucosamine (acetylated unit) which is shown in Fig. 1. Received: 08 April 2016 Accepted: 24 April 2016 Online: 02 May 2016 http://ijps.aizeonpublishers.net/content/2016/3/ijps1524-1533.pdf 1524