Development of a Palm Kernel-Based Emulgel Loaded with Mitracarpus scarber Leaf Extracts for Effective Anti-Inflammatory Activity

Mitracarpus scaber is a tropical herb used in ethnomedicine for the treatment of inflammation and a variety of other diseases. The aim of this study was to develop a palm kernel-based emulgel containing Mitracarpus scarber and examine the product's physicochemical characteristics and anti-inflammatory efficacy on Wister rats. Different batches of emulgel comprising Mitracarpus scarber leaf extracts (MSE), different proportions of oils (palm kernel oil and/or liquid paraffin), and surfactants (tween-80 and/or Cremophor EL-30) were prepared. The freshly prepared and 5-month-old formulations, stored at room temperature (28 ± 2 °C), were evaluated for rheology, syneresis, and extract/excipient compatibility using Fourier transform infrared (FT-IR) spectroscopy. The spreadability, extrudability, and anti-inflammatory activity of the optimal formulation were compared with those of a commercial anti-inflammatory emulgel. Even after five months of storage, the created emulgels remained olive green and creamy, with a homogeneous texture, consistency, and glossy appearance. The optimized batch containing palm kernel oil, tween-80, and xanthan gum had the most stable characteristics, with no significant change in pH (P = 1.000) or FT-IR spectrum after 5 months of storage. It exhibited spreadability and extrudability of 12.75 cm2 and 600 g/cm2, respectively, compared to 16.82 cm2 and 400 g/cm2 for the commercial formulation. Four hours post-treatment, the anti-inflammatory effect of the optimized batch was significantly (P < 0.05) higher than that of the aqueous MSE dispersion. The obtained results demonstrate the prospects of palm kernel-based emulgel loaded with Mitracarpus scarber leaf extracts as an innovative therapeutic approach to inflammation treatment. Keywords: Inflammation, Emulgel, Mitracarpus scarber, Palm kernel oil, Formulation