Formulation Development, Characterization, and Evaluation of a Novel Dexibuprofen-Capsaicin Skin Emulgel with Improved In Vivo Anti-inflammatory and Analgesic Effects.

Abstract

Transdermal application of analgesics allows efficient and painless delivery of medication with minimum side effect. This study was designed with the aim to formulate and characterize dexibuprofen-capsaicin emulgel for transdermal drug delivery with improved anti-inflammatory and analgesic effects. The emulgel was prepared and evaluated for physical examination, stability, spreadability, rheological behavior, viscosity, drug content determination, FTIR analysis, and ex vivo studies. Anti-inflammatory (carrageenan-induced paw edema) and analgesic (hot plate latency test) effects were determined in Sprague-Dawley rats. The dexibuprofen-capsaicin emulgel showed good physical appearance and stability having average pH 5.5 to 6.0, conductivity 73-76s/m, spreadability (12-)17gcm/s, drug content 102.84% ± 0.53 (for capsaicin) and 94.09% ± 0.41 (for dexibuprofen), and FTIR compatibility. It was noted that 86.956% ± 1.46 (with 100mg menthol), 76.687% ± 1.21 (75mg menthol), and 65.543% ± 1.71 (without menthol) of capsaicin were released. Similarly 81.342% ± 1.21 (with 100mg menthol), 72.321% ± 1.31 (75mg menthol), and 52.462% ± 1.23 (without menthol) of dexibuprofen were released. The cumulative amount of capsaicin permeated through rabbit skin was 9.83 ± 0.037μg/cm2 with 100mg menthol (as permeation enhancer), 7.23 ± 0.037μg/cm2 with 75mg menthol, and 2.23 ± 0.061μg/cm2 without menthol after 6.5h. The permeation of dexibuprofen was 19.53 ± 0.054μg/cm2, 13.87 ± 0.032μg/cm2, and 3.83 ± 0.074μg/cm2. Carrageenan-induced paw edema of rat was effectively inhibited by the optimized emulgel. Similarly it was observed that DCE5 shows higher analgesic activity compared with marketed diclofenac sodium emulgel (Dicloran®). The conclusion of this research study evidently indicated a promising synergistic potential of dexibuprofen-capsaicin emulgel as an alternative to the conventional topical dosage form.