In Vitro Liberation of Indomethacin from Chitosan Gels Containing Microemulsion in Different Dissolution Mediums

Abstract

The objective of this research is to outline the liberation of indomethacin from different chitosan gels containing O/W microemulsion. The influence of surfactant, sodium lauryl sulfate, in two concentrations (0.5% and 0.75%, w/w) was determined in dissolution medium on the release of indomethacin, which was used as poor water-soluble model drug. Chitosan gels were prepared in four different concentrations of chitosan-1%, 1.5%, 2%, and 3% (w/w). Microemulsion enhanced the liberation of the indomethacin from chitosan gels into all dissolution mediums. Adding the surfactant into phosphate-buffered saline decreased the amount of liberated indomethacin from microemulsion, gel mixture, but increased the drug liberation from pure chitosan gels. It was detected that with the increased concentration of chitosan in the samples, the amount of indomethacin liberated (p < 0.05) also increased. A conclusion was drawn that the liberation of indomethacin from chitosan gels was influenced by increased pH of the samples. The high viscosity induced a higher release of indomethacin from 3% (w/w) chitosan hydrogel at pH 5.8 as compared with 3% (w/w) chitosan hydrogel at pH 3.8. The highest percentage of released indomethacin was determined when a mixture of microemulsion gel with higher chitosan content was used.

Preparation and Characterization of Lidocaine-Loaded, Microemulsion-Based Topical Gels

“…Based on the best goodness of fit (see Table 5), it was found that MG 3 , MG 4 , and the marketed product were followed Higuchi kinetic model (MG 3 : R 2 = 0.9942, MG 4 : R 2 = 0.9862, marketed gel: R 2 = 0.9832). Higuchi model-based permeation, previously reported for indomethacin (chitosan-based), terbinafine (chitosan-based), itraconazole (Lutrol ® F127based) and ibuprofen (Carbopol ® 940-based) MBGs and for topical ketoprofen and pentoxifylline MEs (24,(60)(61)(62)(63)(64), suggests that the release process could be mainly controlled by the Fickian diffusion of dissolved lidocaine through the gel network of Carbomer ® 940. However, the analysis of the release plot for MG5 revealed that lidocaine followed the first-order model for controlled permeation, suggesting that the release rate is concentration-dependent (23,65).…”

“…A quantity of 200 mg of the gel was applied to the membrane, and the donor chamber was covered with Parafilm ® . At predetermined time intervals (5,7,10,15,20,30,45,60,75,90,105, and 120 min), an aliquot of 2 mL sample was taken from the release medium, and the same volume of the fresh buffer was added to the receptor chamber to maintain the sink condition. During the test, the diffusion cells were checked for the presence of a bubble on both sides of the membrane.…”

Encapsulation and controlled release of vitamin C in modified cellulose nanocrystal/chitosan nanocapsules

“…Various types of mathematical models have been used to determine the kinetics of drug release from the delivery systems, such as zero order, first order, and Higuchi model ( Starychova et al., 2014 ; Zandi, 2017 ). These dissolution models are necessary to study the release mechanism of drugs, as it mathematically describes the release profiles, such as the release of VC.…”

Bacterial Cellulose—A Remarkable Polymer as a Source for Biomaterials Tailoring

“…Chitosan exhibits many excellent properties, such as biocompatibility, non-toxicity, biodegradability, particular solubility, along with antimicrobial [ 135 , 136 ], antioxidant [ 137 ], antiviral, and antifungal effects [ 138 ]. Chitosan is well known as an excipient for drop-type ophthalmic products [ 139 ], and also for complex entities like liposomes [ 140 ], microemulsions [ 141 ], hydrogels [ 142 ], and implants [ 143 ]. Due to its excellent characteristics, chitosan can be used as a scaffold alone or in association with other polymers to develop new materials with promising biomedical uses.…”