Development and characterisation of water soluble chitosan and its effect on skin penetration in caffeine cream

Chitosan and chitosan derivatives have been used in medical, cosmetic and biotechnology preparations. It has been shown to have antibacterial, hydrating, and wound healing properties. It also can act as a penetration enhancer. Chitosan is insoluble in water, hence a main problem for formulation. In this study, insoluble low molecular weight chitosan was converted into water soluble chitosan using cheap hernicellulase enzyme. It was then characterised using FTIR, XRD and Contact angle measurement. Then it was incorporated into the caffeine cream at a percentage of 2%, 3% and 4% w/w respectively. All creams were characterised using Mastersizer and Rheometer to see the particle size, uniformity and viscosity. Skin penetration studies were conducted via Franz cell diffusion equipment. The results obtained showed after enzymatic degradation, chitosan became soluble in water. This will ease formulation of the caffeine cream. FTIR spectrum water soluble chitosan showed that the backbone of chitosan remained intact. XRD showed that the crystal structure of LMWT chitosan changed from crystalline to amorphous after the enzymatic degradation, while the contact angle studies also showed that contact angle of water soluble chitosan and water was <45° which indicated a higher degree of wettability properties. However, penetration studies showed negative results. This may be due to the inconsistent formulation and human error during the experiments.