Antibacterial activity of formulated Psidium guajava (guava) hand sanitizer gel on Staphylococcus aureus

The primary purpose of the study was to detect the bactericidal potential of a formulated guava hand sanitizer gel on Staphylococcus aureus.  The efficacy of this formulation was tested against a bacterial strain through the well-diffusion method. Inhibition of Staphylococcus aureus growth was compared across two independent variables: (a) the type of sanitizer (experimental guava hand sanitizer gel vs. three other commercial brands); and (b) the type of alcohol utilized (experimental guava hand sanitizer gel vs. isopropyl vs. ethyl alcohol). The dependent variable which is the reduction of S. aureus growth rate, was measured by the zone of inhibition in each of the bacterial strains. Experimental design was used to measure the bactericidal potential of guava hand sanitizer gel. Through a two-way ANOVA, no significant difference was found between groups of commercial hand sanitizers and the formulated guava hand sanitizer gel (Brand A with a zone of inhibition of of 9.7 mm, Brand B with 9.3 mm, Brand C with 9 mm, and the new formulation with a zone of inhibition of 9 mm). These findings reveal that the reference standard commercial product (Brand A) with a highest zone of inhibition manifests a similar antibacterial property with the formulated guava hand sanitizer gel as revealed by bacterial reduction rate. In conclusion, the formulated hand sanitizer possesses antibacterial potential to inhibit the multiplication of S. aureus. Further studies should be conducted on other therapeutic activity parameters and the elucidation of structure for the active constituent with potential as bactericidal.