Eutexia for enhanced dissolution rate and anti-inflammatory activity of nonsteroidal anti-inflammatory agents: Caffeine as a melting point modulator.

Fast dissolution of nonsteroidal anti-inflammatory drugs (NSAIDs) is a prerequisite from patient perspective. However, most NSAIDs are slowly dissolving acidic compounds. Caffeine, a commonly used analgesic adjuvant with NSAIDs showed high potential as eutectic co-former for acidic compounds. The study investigated eutectic forming potential of caffeine with meloxicam, aceclofenac and flurbiprofen. Each drug was co-ground with caffeine in various ratios and the products were characterized by thermal analysis to determine the optimum eutectic composition from phase diagram and Tamman's triangle. The optimum systems were subjected to X-ray powder diffraction (XRPD), Fourier-transform infrared (FTIR) and dissolution studies. Co-ground systems at dose ratio were also assessed for drug dissolution and anti-inflammatory effect using carrageenan induced rat paw edema method. Eutexia was confirmed by thermal analysis with the optimum composition being 1:1, 1:1 and 1:2 (NSAID: caffeine) for aceclofenac, flurbiprofen and meloxicam, respectively. Eutexia did not alter FTIR spectra with minor changes being recorded in XRPD patterns. The eutectic systems underwent fast liberation of drugs with fast dissolution being retained even at dose ratios. Dissolution enhancement was associated with enhanced anti-inflammatory response. The study introduced caffeine as eutectic forming analgesic for fixed dose combination with NSAIDs to enhance drug dissolution and anti-inflammatory effect.