PH-responsive poly(lactic acid)/sodium carboxymethyl cellulose film for enhanced delivery of curcumin in vitro

Abstract

Curcumin is a nutraceutical having variety of pharmacological activities including chemopreventive and chemotherapeutic properties. However, it is poorly absorbed after oral administration due to the low solubility, rapid metabolism and pre-systemic metabolic degradation. In this study, poly(lactic acid)/sodium carboxymethyl cellulose/curcumin film prepared by solvent casting method is proposed to improve the curcumin (CUR) release in intestinal alkaline condition. Cellulose extracted from oil palm empty fruit brunch (OPEFB) is modified into sodium carboxymethyl cellulose (CMC) using etherification process. Prepared CMC is introduced to the film with the aim of enhancing the solubility of curcumin and imparting pH sensitivity to the film. Fourier transform infrared spectroscopy (FTIR) confirms the successful carbomethylation of cellulose. The solubility of curcumin increases from 24 ± 0.38 mg/L to 147 ± 5.66 mg/L with increasing the CMC content from 0.1% to 2% (w/v) in phosphate buffered saline (PBS) medium. The tensile strength of the film decreases upon the addition of CMC, but elongation at break increases with the addition of 16% CMC to the film. The films show pH triggered swelling pattern with the highest swelling ratio of 707 ± 10.91% at pH 12. The in vitro release profiles of the films are consistent with the results of the swelling studies and it shows pH sensitivity towards the drug release. The cumulative drug release increases from 0.81 ± 0.09 mg/L to 8.41 ± 0.04 mg/L with increasing the CMC content from 0% to 80% of the film in phosphate buffer saline (PBS) medium. It is around 7-fold increase compared to simulated gastric fluid (SGF) medium. However, the encapsulation efficiency slightly decreases with increasing the CMC content. According to the results of this study, PLA/CMC/CUR films can be suggested to improve the curcumin release in the intestinal alkaline condition.