Abstract
Purpose: To compare the antibacterial-enhancing efficacy of aloe vera and honey in salicylic acid
topical formulations against acne.
Method: Six formulations containing 5 % salicylic acid were developed as creams and gels as follows:
Formulations S, V and H were creams containing salicylic acid alone (S), salicylic acid with 28 % aloe
vera (V), and salicylic acid with 10 % honey (H). Formulations J, M, and B were gels containing salicylic
acid alone (J), salicylic acid with aloe vera 20 % (M) and salicylic acid with 12 % honey (B). Each
formula was evaluated for colour, odour, pH, viscosity, spreadability, and stability under different
temperatures (25, 30, and 60 oC) and times (1 hour, 1 day, and 1 week). Furthermore, antibacterial
activity was determined using the agar well diffusion method against Escherichia coli, Staphylococcus
aureus, Enterobacter spp., Pseudomonas spp., Proteus, and Klebsiella spp.
Results: The formulations exhibited distinct colours and odours, with pH values ranging from 4 to 6,
viscosities between 3813 and 9813 cP, and spreadability from 10 to 45.5 (g*cm/s). Antibacterial activity,
measured by inhibition zone diameters, varied from 0.4 to 2.5 cm against different bacterial strains (p <
0.001). Creams (S, V, and H) exhibited high selectivity, showing strong activity against Gram-positive
bacteria such as S. aureus but limited effectiveness against Gram-negative rods like Proteus. In
contrast, gel formulations (J, M, and B) showed a broader and more consistent spectrum of activity. All
formulations showed stability for up to one month, even with temperature fluctuations, while maintaining
a skin-compatible pH.
Conclusion: Formulations containing aloe vera and honey increased the antibacterial activity of
salicylic acid, thereby making them suitable adjuvants in anti-acne formulations.
Keywords: Anti-acne cream, Salicylic acid, Anti-bacterial cream, Cream formulation, Gel formulation
