Formulation and in vitro, in vivo characterizations of colchicine loaded nanoemulsion for gout management

Colchicine is an alkaloid and potent anti-inflammatory agent used as a drug of choice for gout. Oral administration of colchicine may result in gastrointestinal (GI) disturbances. Intravenous administration of colchicine is even more dangerous and can result in necrosis and cytopenia. These limitations require the development of a topical colchicine nano-emulsion for rapid and effective treatment of pain and inflammation in gout. A high-speed homogenization technique was used for the development of nano-emulsions loaded with colchicine. Trial and error method was used for formulation composition and optimization. The optimized nanoemulsion (F5) exhibited a uniform droplet size with stable surface characteristics. Differential scanning calorimetry (DSC) confirmed successful drug incorporation without significant alterations in its thermal properties. Fourier transform infrared spectroscopy (FTIR) study showed no interaction between drug and other ingredients in formulation. The nanoemulsion demonstrated sustained drug release following the Higuchi kinetic model, indicating a diffusion-controlled mechanism. Pharmacodynamics assessments revealed enhanced analgesic effects, with a prolonged pain relief response in the hot plate test. Additionally, the paw edema model showed a significant reduction in inflammation, comparable to the standard treatment. These findings concluded that the nanoemulsion-based system offers a promising approach for colchicine delivery in gout management.