Development and evaluation of Ibuprofen transdermal gel formulations

Purpose: To develop an ibuprofen transdermal gel with a capability for both topical and systemic drug delivery. Methods: Ibuprofen gel formulations, incorporating various permeation enhancers, were prepared using chitosan as a gelling agent. The formulations were examined for their in vitro characteristics including viscosity, pH and drug release as well as in vivo pharmacological activities. Carrageenan-induced rat paw oedema model was used for the evaluation of their analgesic and anti-inflammatory activities. A commercial ibuprofen gel product (Ibutop® ) was used as a reference. Results: The formulations containing 5 % of either menthol or glycerol as permeation enhancers gave drug release patterns comparable to that of the reference product. Propanol increased the apparent viscosity of the test gels to the same extent as that of the reference. Drug release from the formulations fitted best to the Higuchi model. A significant in vivo analgesic effect was produced by the test formulations containing 5 % menthol and 20 % propylene glycol and the effect was superior to that obtained with the reference product. However, no significant anti-inflammatory activity was exerted by any of the test gel formulations (p > 0.05). Conclusion: Ibuprofen gel preparations containing 5 % menthol and 20 % propylene glycol, respectively, exhibited pronounced analgesic activity and could be further developed for topical and systemic delivery of ibuprofen.