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 73-76 s/m, spreadability (12-)17 g cm/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 100 mg menthol), 76.687% ± 1.21 (75 mg menthol), and 65.543% ± 1.71 (without menthol) of capsaicin were released. Similarly 81.342% ± 1.21 (with 100 mg menthol), 72.321% ± 1.31 (75 mg menthol), and 52.462% ± 1.23 (without menthol) of dexibuprofen were released. The cumulative amount of capsaicin permeated through rabbit skin was 9.83 ± 0.037 μg/cm2 with 100 mg menthol (as permeation enhancer), 7.23 ± 0.037 μg/cm2 with 75 mg menthol, and 2.23 ± 0.061 μg/cm2 without menthol after 6.5 h. The permeation of dexibuprofen was 19.53 ± 0.054 μg/cm2, 13.87 ± 0.032 μg/cm2, and 3.83 ± 0.074 μg/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.
Keywords: analgesic; anti-inflammatory; capsaicin; dexibuprofen; emulgel; transdermal drug delivery.