The present study aimed to formulate and characterize tobramycin-loaded invasomal gel for effective topical drug delivery. Invasomes were prepared using phospholipids, ethanol, and terpene components to enhance skin permeation and drug retention. The prepared formulations (F1–F6) were evaluated for vesicle size and entrapment efficiency. The vesicle size was found in the range of 198.30–248.40 nm, indicating suitability for enhanced skin penetration. Among all formulations, F2 showed the smallest vesicle size and highest entrapment efficiency (83.55%), and was selected as the optimized formulation. The optimized invasomes were incorporated into gel formulations (IG-1 to IG-3) and evaluated for physicochemical parameters such as pH, viscosity, drug content, extrudability, and spreadability. All formulations exhibited acceptable properties suitable for topical application. Among them, IG-2 showed optimal characteristics with high drug content and appropriate consistency. In-vitro drug release studies demonstrated that the invasomal gel provided sustained drug release up to 12 hours (90.25%), whereas the pure drug showed rapid release within 4 hours. Release kinetics indicated that the formulation followed Higuchi and Korsmeyer–Peppas models, suggesting a diffusion-controlled release mechanism. In conclusion, the developed invasomal gel system enhances drug entrapment, provides controlled release, and improves topical delivery of tobramycin. The optimized formulation shows potential for effective treatment of topical infections with improved therapeutic efficacy and patient compliance.
Naveen Kumar Pandey*, B. K. Dubey, Mukesh Kumar Patel, Deepak Basedia, Sunil Shah (Wed,) studied this question.