Evaluating the potential of a solid dispersion of curcumin in the management of osteoarthritis

Abstract

Osteoarthritis (OA) is a progressive degenerative joint disorder characterized by cartilage breakdown, swelling, pain, and functional impairment. Pharmacotherapy provides symptomatic relief limited by adverse effects during long-term use. Curcumin exhibits anti-inflammatory and antioxidant properties relevant to OA management but has poor oral bioavailability. This study was aimed at formulating and characterizing solid dispersions of curcumin using sodium starch glycolate (SSG) as the hydrophilic carrier, while assessing its therapeutic efficacy on osteoarthritis. The solvent evaporation method was used to prepare solid dispersions of curcumin (SDC) at different ratios of 1:1 (Batch A), 1:2 (Batch B) and 2:1 (Batch C) of curcumin to SSG respectively. The SDCs were evaluated for percentage loading, aqueous solubility, flow characteristics, differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). Stability was also evaluated. The in-vivo anti-inflammatory effect was investigated using albino rats while limping behaviour, knee swelling and percentage arthritic inhibition were assessed. The batch B SDC exhibited the best in vitro release and had a 2.4-fold increase in solubility relative to batch A. DSC thermograms showed reduction in curcumin crystallinity for all batches. FTIR did not show any chemical interaction between curcumin and SSG. Batch B exhibited fair flow with compressibility index of 17 % and Hausner’s quotient of 1.2. Batch B showed the least degradation during stability testing after 4 weeks. Batch B achieved the highest reduction in limping and swelling, closely approximating diclofenac group which served as the positive control. Percentage arthritic inhibition increased over 28 days, with batch B showing superior efficacy compared to other formulations.