Studies on the carboxymethyl chitosan-containing liposomes for their stability and controlled release of Dapsone

Abstract

Stable liposomes containing carboxymethyl chitosan (CMC) were prepared and characterized. CMC was introduced in the phosphatidyl choline (PC) liposomes by different methods; firstly, CMC in a free state in the aqueous phase; secondly as a coat (coupled); and finally as a conjugate of dapsone. The stability of liposomes was assessed by their disintegration in ethanol and surfactants. Both hydrophilic bromothymol blue and lipophilic dapsone were encapsulated in these liposomes and their in vitro release studies were carried out at 37 degrees C using different media, namely, phosphate buffer (pH 7.4), 0.02 N-HCl and 1% mouse plasma. The conjugate of dapsone with CMC present in PC liposomes gave the best results in its stability as compared to other modified liposomes. The release data of dapsone also confirmed the results of the stability studies on liposomes. CMC-dapsone conjugate released the dapsone much slower in all three media than did PCCMC and PCCMC-coat liposomes.

Liposomes as Potential Drug Carrier Systems for Drug Delivery

“…Some improvements in chemical and physical stability of polymer coated liposomes prepared with polysaccharide derivatives, such as mannan or amylopectin, have been demonstrated [64]. Several other substances also have been used for preparation of polymer coated liposomes such as poloxamer, polysorbate 80, carboxymethyl chitosan, and dextran derivatives [65][66][67][68][69]. While the possibility of coating liposomes with these polymers has been reported, few papers have dealt with the systematic evaluation of the physical stability of polymer coated liposomes.…”

Effect of chitosan coating on the characteristics of DPPC liposomes

“…Several authors have used chitin or chitosan related polymers as a liposome coating in order to increase their stability towards drug release [20,21], to stabilise haemosomes 'Artificial Red Blood Cells' [22,23], and for targeting purposes [24].…”

Gastroretentive Dosage Forms for Prolonging Gastric Residence Time

“…[81] mucoadhesive polymers such as chitosan, carbopol, carboxRecent advances in the field have led to 'superporous hydrogel ymethyl chitin and carboxymethyl chitosan. [85,86] Negatively hybrids', which are prepared by adding a water-soluble or watercharged liposomes can be prepared with L-α-dipalmitoyl dispersible polymer that can be cross-linked after the superporous phosphatidylcholine (DPPC) and diacetylphosphate (DCP) by the hydrogel is formed. Examples of hybrid agents include thin film hydration method.…”