Formulation and Physical Characterization of Bio-Degradable Chitosan-Poloxamer Gel Base for Local Drug Delivery

Objective: Thermo-modulated in-situ hydrogel (TSHG) are formulated routinely utilizing poloxamer for extended drug release. However physical properties of such formulations may have some flaws, which can be rectified using a combination of polymers with better physical properties such as chitosan. The purpose of the present study was to fabricate biodegradable chitosan-poloxamer-based in-situ drug delivery systems and assessment of their physical properties. Methods: The present chitosan-poloxamer gel base was formulated using a two-stage method. Initially, chitosan gel was prepared by dissolving 1% w/w chitosan in glacial acetic acid. The poloxamer gel was prepared using “cold method”. The final chitosan-poloxamer gel base was prepared by mixing equal amounts of both solutions and evaluated for physical and mechanical properties. Result and Discussion: The DSC thermogram demonstrated no obvious interactions among ingredients or micellization temperature. The gelation temperature of the gel was between 27 and 330C. The pH was 7 with slight clarity. The viscosity of the gel ranged from 15.14 to 41.19 pa.s. The gel was syringable between 4-300C and biodegradable under physiological conditions. The mean particle size of the gel under SEM was found in the range of 300-554 nm. Conclusion: After the evaluation of the formulation, it can be concluded that all the ingredients in the gel showed good compatibility with each other, which could form a stable and homogeneous gel with favorable mechanical and physical properties. Keywords: chitosan, drug delivery system, hydrogels, poloxamer