Development and Evaluation of pH-Sensitive Polyethylene Glycol Hydrogels Containing Aloe Barbadensis for Sustained Drug Release in Ulcerative Colitis Treatment"

Abstract

The present study explores the development and evaluation of pH-sensitive polyethylene glycol (PEG) hydrogels loaded with Aloe Barbadensis for controlled drug release, particularly for localized treatments like ulcerative colitis. Aloe Barbadensis, a popular medicinal plant, is utilized as the therapeutic agent due to its known healing properties. Various PEG-based hydrogels were synthesized through different combinations of gelatin (Monosan), monomers, and cross-linkers to assess their impact on hydrogel properties. The gel content percentage and gel formation time were key parameters measured during the hydrogel preparation. Results showed that PEG-1 to PEG-3 formulations, which had increasing concentrations of gelatin, exhibited lower gel content percentages, with values between 70% and 80%. In contrast, formulations PEG-4 to PEG-6, with higher monomer content, demonstrated significantly higher gel yields, ranging from 80% to 90%. The time required for complete gel formation was shortest in formulations with higher monomer and cross-linker concentrations, reaching completion within 2–3 hours. In vitro drug release studies, conducted under pH 1.2 and pH 7.4 conditions, revealed that Aloe Barbadensis release was highly pH-dependent. At pH 1.2, the release was minimal, showing around 20% drug release, while at pH 7.4, the cumulative release reached approximately 89% within 48 hours. This data confirms that Aloe Barbadensis-loaded PEG hydrogels exhibit a pH-responsive drug delivery system, with controlled and sustained release, making them a promising option for localized topical applications in conditions like ulcerative colitis.