Novel Aspasomal Gel Formulation with Enhanced Dapsone Solubility for Effective Treatment of Acne

The current study was aimed to enhance the solubility of dapsone by encapsulating it within innovative vesicles known as aspasomes. The thin film hydration technique was employed to prepare vesicles, and various formulations were developed utilizing a central composite design approach. The impact of ascorbyl palmitate and cholesterol on entrapment efficiency and drug diffusion was examined. An optimized formulation was selected to achieve the highest entrapment efficiency and facilitate effective drug diffusion. It was loaded into a 2% w/v of xanthan gum gel base and assessed for drug content, pH, spreadability, viscosity, drug diffusion (in vitro and ex-vivo) and antibacterial activity. Entrapment efficiency and drug diffusion of formulations were within the range of 70 ± 0.3 to 97.58 ± 0.8% and 53 ± 2.31 to 87 ± 3.43%, respectively. Optimized aspasomes were spherical with a polydispersity index, zeta potential, and vesicle size of 0.33, -47.2 mV and 110 ± 14 nm, respectively. The optimized formulation demonstrated a drug diffusion rate of 89.24 ± 3.13% for 5 h, while the entrapment efficiency was 90.23 ± 0.21%. The drug content and pH of aspasomal gel were 97.2 ± 0.2% and 6.2 ± 1.28, respectively. Aspasomal gel was less viscous and more spreadable than the marketed gel. In-vitro and ex-vivo diffusion studies of the aspasomal gel were indicative of 82.47 ±1.98 and 85.9 ± 2.56% diffusion, respectively. For the marketed gel, the diffusion rates were 76.84 ± 0.2% and 71.68 ± 3.14%. The zone of inhibition of aspasome gel (40 ± 1.8 mm) was better than the marketed formulation (28 ± 0.04 mm) against Propionibacterium acnes. The aspasomal formulation is a better choice for enhancing the solubility, permeability and antibacterial activity of dapsone.