Transdermal microgels of gentamicin.

Phospholipid-modified solid lipid microparticles (SLMs) of Phospholipon® 90G and 90H encapsulating the hydrophilic drug, gentamicin were produced and loaded into three polymeric hydrogels of Poloxamer 407 and polyacrylic acids (Carbopols® 971P and 974P). The SLMs were characterized by morphology and particle size, drug encapsulation efficiency, thermal properties, pH, and storage stability, whereas the microgels were evaluated for viscosity, spreadability, pH, drug content, and in vitro antimicrobial drug release against five microorganisms (Klebsiella spp., Escherichia coli, Bacillus subtilis, Staphylococcus aureus, and Pseudomonas aeruginosa). Our results generally showed Poloxamer 407 microgels of P90H and P90G as having the most desirable properties in terms of fast antibacterial activity on all tested microorganisms, in vitro diffusion-dependent permeation through rat abdominal skin, spreadability, pH, and viscosity, superior to polyacrylic acids microgels.