Study of Complex Coacervation of Chitosan with Sodium Carboxymethyl Cellulose: Microencapsulation of Neem Seed Oil and Isoniazid

Abstract

Microparticles containing natural liquid pesticide neem (Azadirachta Indica A.Juss.) seed oil (NSO) and a solid antitubercular drug, isoniazid were prepared using complex coacervation technique and employing chitosan and sodium carboxymethyl cellulose polyelectrolyte complex. Turbidity measurement was carried out to evaluate the pH and ratio of the two polymers that produced highest yield. Effective coacervation was realized over the pH range of 2.5-3.5 using the chitosan and sodium carboxymethyl cellulose ratio of 1:2.33.The encapsulation efficiency of NSO and Isoniazid were dependent on the amount of crosslinker, oil/drug loading and polymer concentration. Scanning electron micrographs showed the formation of free flowing spherical microparticles in case of isoniazid loading and a bit agglomerated in case of neem seed oil loading. The size of microparticles tends to increase with the increase of the concentration of the polymer. Thermogravimetric analysis showed the improvement of thermal stability with crosslinking. Fourier Transform Infrared Spectroscopy study showed that there was no significant interaction between NSO/drug and chitosan and sodium carboxymethyl cellulose complex.