Purpose: To formulate hydrogels based on poloxamer 407 and polyacrylic acids (Carbopols® 971P and 974P), and evaluate its suitability for enhanced topical delivery of gentamicin, a potent but highly toxic aminoglycoside antibiotic.

Methods: Topical hydrogels of gentamicin were produced using poloxamer 407 and polyacrlic acids (Carbopols® 971P and 974P), and evaluated in terms of drug content, pH, physical assessment, viscosity and stability. In vitro antimicrobial drug release was conducted using four microorganisms – Escherichia coli, Salmonella typhi, Staphylococcus aureus and Pseudomonas aeruginosa.

Results: Stable gentamicin-loaded hydrogels with good encapsulation efficiency (maximum EE% of 85.76 to 90.66 %) as well as greater zones of inhibition against all organisms (maximum range: 22.34 ± 2.35 to 29.40 ± 3.07 mm) than commercially available gentamicin ointment and pure sample of gentamicin (p < 0.05), were produced. Overall, poloxamer 407 hydrogels of gentamicin gave the most desirable properties in terms of pH, viscosity and rapid concentration and time-dependent antibacterial activity on all tested micro-organisms, superior to polyacrylic acids hydrogels of gentamicin.

Conclusion: This study demonstrates that poloxamer 407 hydrogels of gentamicin may offer a promising approach for topical delivery of gentamicin for the treatment of skin infections caused by gentamicin-susceptible bacteria.