Design of two liquid Ibuprofen-poloxamer-limonene or menthol preparations for dermal administration

The purpose of our study was to prepare liquid forms of 20% ibuprofen in 30% poloxamer 407, while avoiding gel formation and to assess their drug diffusion-penetration (permeation) into the skin. Two series of poloxamer-based formulations were prepared, both containing ibuprofen and one of two terpenes: d-limonene and 1-menthol. A rheological characterization of all preparations made allowed their grouping in two modalities: gels and fluids. Data revealed a statistically superior enhanced permeation terpene-dependent of ibuprofen in fluid preparations, specially the one containing d-limonene. Cumulative permeation in 24 hr was 2500 micro g/cm(2) and 4500 micro g/cm(2) for the 1-menthol and d-limonene, respectively, for fluid preparations as compared with 2000 micro g/cm(2) and 1600 micro g/ cm(2) for d-limonene and 1-menthol on gels and only 1200 micro g/cm(2) of the control solution (p < 0.05). Results postulate that a liquid 30% poloxamer-based preparation of ibuprofen with d-limonene is possible and that it may be useful as a topical preparation of ibuprofen.