Potential of antimicrobial topical gel with synthesized biogenic silver nanoparticle using Rhodomyrtus tomentosa leaf extract and silk sericin

Objective Silver nanoparticles synthesized using Rhodomyrtus tomentosa leaf extract and silk sericin were used to functionalize carbopol 940 gel for topical applications. Results UV–vis spectra presented surface plasmon resonance at 426 nm, transmission electron microscopy revealed that nanoparticles were spherical with an average size of 25–50 nm. X-ray diffraction presented crystalline silver nanoparticles with zeta potential of ≈ − 30 mV. FTIR spectra showed a reduction of silver nitrate indicated by the shift in –OH at 2958 cm –1 . The silver nanoparticle demonstrated broad-spectrum antimicrobial activity against Gram-positive, Gram-negative and fungi with MIC ranging between 0.26 and 2.10 μg mL −1 , respectively. MIC of hydrogel ranged between 1.05–2.10 μg mL −1 with cell viability of 89%. Spreadability and extrudability of gel were 9.3 ± 0.85 s and 19.85 ± 0.03%, respectively with first order of fickian diffusion. Conclusions The silver nanoparticle gel exhibited an effective antimicrobial property, hence can be exploited for topical applications.