Comparative in vitro dermatokinetics of ibuprofen (IBP)

IBP, a widely used non-steroidal antiinflammatory analgesic exhibits low solubility in acidic media (gastric environment) and inadequate pharmacokinetics when administered orally. Thus, IBP warrants investigation for better, more effective and faster localized therapeutic effect of the drug as an alternative to oral treatment. The potential of IBP of in vitro percutaneous uptake and dermal absorption was evaluated for possible topical therapy. IBP reservoir systems [IBP + various ointment bases] at various drug loading levels [doses: 200, 400 and 600 mg] were evaluated for drug release rate as well as mechanism of drug release. Additionally, recommendations were generated for rational development of optimally effective dermal products of IBP. IBP reservoir systems were evaluated for in vitro dermal uptake by employing modified franz diffusion cell. A semipermeable membrane was sandwiched between the donor compartment containing the IBP-reservoir system and the receptor compartment containing Sorenson's buffer at pH 7.4. The release rate of IBP was followed for 12 h. Release of IBP from various systems exhibited linear relationship with square-root of time dependence indicating adherence to diffusional pathway. The rate of release of IBP increased with increase in drug load [dose]. Cumulative Qmax/Dose as a function of Dose was employed to generate recommendations for development of dermal product(s) for IBP. An oil-in-water system [Acid Mantle Creme (A/M Creme)] exhibited superior drug release characteristics over others in this investigation. This study demonstrated that IBP release characteristics can be effectively manipulated by incorporating changes in the system composition as well as drug loading.