Formulation and Characterization of Diclofenac Sodium Nanogel for Controlled Drug Release

Diclofenac sodium (DFS) is used for treating both inflammation and pain-associated arthritis. Oral administration of DFS is limited by its short half-life. Its use may result in serious gastrointestinal issues, including inflammation, internal bleeding, and ulceration. Novel drug delivery systems have been investigated to enhance the bioavailability of DFS. This study focuses on formulating and evaluating a diclofenac sodium nanogel (DNG). A nanogel was produced via a modified emulsification-diffusion process, employing polymers such as eudragit S-100, carbopol-940, and solvents like glycerol and ethylacetate. The properties of formulated DNG, including pH, viscosity, drug content, entrapment efficiency (EE), spreadability, swelling index, and drug release percentage, were evaluated. FTIR spectra confirmed that there is no interaction between the drug and excipients. 7 formulations, F1-F7, have been prepared. The DNG results demonstrated excellent EE, drug release, pH- sensitivity, and stability. 98.9% of drug from glycerin-based nanogels (F2) were released within 8 hours. The kinetic pattern for all formulations was zero-order. This study shows that using nanogel formulation for DNG transdermal delivery can sustain the drug's release for up to 8 hours and have good stability during study period (6 months).