Physical Characterisation and Stability Study of Formulated Chromolaena odorata Gel

Background: Formulation of topical products for skin delivery that fulfill good formulation criteria has always been a challenge for pharmaceutical scientists. Despite the challenges, gelbased drug delivery offers some advantages such that it is non-invasive, painless, involves avoidance of the first-pass metabolism, and has satisfactory patient compliance. Objectives: In this study, C. odorata gel and quercetin gel (bioactive flavonoid compound) were successfully formulated and compared with placebo and conventional wound aid gel. The chromatographic profiling was conducted to screen the presence of phytoconstituents. Subsequently, all formulated gels were evaluated for physical characteristics and stability. Methods: Reverse Phase High-Performance Liquid Chromatography (RP-HPLC) of C. odorata methanolic leaves extract showed a distinct compound separation at a retention time of 8.4min to 34.8 min at 254nm. All gels were characterised by evaluating their rheological properties, including storage modulus, loss modulus, and plastic viscosity. Besides, texture analysis was performed to measure the firmness, consistency, cohesiveness, and viscosity index of the gels. Results: According to the results, C. odorata gel demonstrated better spreadability as compared to the other gels, which required less work and was found to be favourable for application on the skin. Moreover, C. odorata gel showed no changes in organoleptic properties and proven to be stable after 30 days of accelerated stability study at 40°C ± 2°C with Relative Humidity (RH) of 75% ± 5%. Conclusion: C. odorata gel was found to be stable, reflecting the combination of materials used in the formulation, which did not degrade throughout the study. This work suggests the potential of this gel as a vehicle to deliver the active ingredients of C. odorata to the skin, which can be further explored as a topical application for antimicrobial wound management or other skin diseases study.