Silver Sulfadiazine Nanocrystal-Based Hydrogels: The Impact of Lipid Components on In-vitro and Ex-vivo Release, Bacterial Biofilm Permeability, and In-vitro Antibacterial Activity

This study developed a new formulation for silver sulfadiazine (SSD) nanocrystal-based hydrogels for in vitro antimicrobial activity.

SSD nanocrystals were prepared by using a wet-mill apparatus; effects of polymers, surfactants and lipid-based carriers were investigated. The gel-forming chemicals were subsequently dispersed in the SSD nanocrystal nanosuspensions, resulting in homogeneous hydrogels. The antibacterial activities of new formulations were tested in-vitro.

The final SSD nanocrystal formulation (less than 300 nm, PDI: 0.300) containing glyceryl monostearate (GMS) or lecithin (Lec), combining with hydrophilic polymers (hydroxypropyl methyl cellulose and polyvinyl alcohol). The artificial neural network was utilized to confirm the effects of lipid ingredients in wet-milling process. Hydroxyethyl cellulose was chosen to formulate the hydrogel which formed the white, smooth, homogeneous, and stable hydrogel after 4 weeks at the room condition. The hydrogel also presented higher and more sustained drug release using Franz’s diffusion cells as compared with reference marketed drug and control hydrogels. The efficacy of antibacterial activity shown on the biofilm demonstrated effect of particle size, lipid carriers, and probably interaction between SSD with biofilm membrane.

These findings implied a potential application of SSD nanocrystal-lipid carrier-based hydrogels in clinical practice.