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.
