Includes bibliographical references

The study confirmed that eggplant (Solanum melongena) peel has antibacterial activity against Staphylococcus aureus and can be formulated into a stable topical ointment, supporting its potential as a sustainable alternative antibacterial agent. Further studies are recommended to quantify active compounds, evaluate broader antimicrobial activity and assess stability, safety, and in vitro efficacy. The eggplant peel extract was obtained through 70% ethanol maceration and concentration after which it underwent both phytochemical screening and organoleptic evaluation. Toxicity and the EDso for the extracts were determined using the brine shrimp lethality assay and probit analysis. Antibacterial activity against Staphylococcus aureus for both the extract and the formulated ointment was tested using the agar well diffusion method with the positive control being mupirocin and the negative control being the untreated ointment base. Quality control tests were performed on the physical properties of the resulting ointment. The Brine Shrimp Lethality Assay (BSLA) was performed to compare the toxicity and effective dose concentration for the tested samples. For each selected sample, the median effective dose (EDso) was calculated using probit analysis. Results obtained from BSLA indicated that the eggplant peel extract contained bioactive phytochemicals that were particularly abundant in phenolic compounds and flavonoids, which showed evidence of antibacterial activity against Staphylococcus aureus based on the presence of clear zones of inhibition. Data collected on the formulated eggplant peel ointment also indicated significant isolates were retained in the eggplant material after topical application, as the antibacterial activity of the eggplant peel ointment was similar to that of mupirocin at higher concentrations and was not statistically different (= 0.05).