green formulation of an antibacterial bath soap using elatostema rostratum leaf extract as a sustainable natural agent

Antibacterial soap plays a vital role in maintaining skin hygiene and preventing infections caused by pathogenic microorganisms. this study aimed to develop a transparent solid soap formulated with cocok bubu (elatostema rostratum (blume) hassk) leaf extract, an endemic plant from sukabumi, as a natural antibacterial agent. the extraction was performed by maceration using methanol, and the extract was subsequently concentrated using a rotary evaporator. the soap was formulated with 50% extract concentration and evaluated for its physicochemical quality parameters, including ph, moisture content, free alkali, foam height, and saponification value. additionally, skin irritation and antibacterial activity tests were conducted against staphylococcus aureus. the results showed that the produced soap met the indonesian national standard (sni), with ph 9.49, moisture content 10.2%, free alkali 0.032%, saponification value 210.4 mg koh/g, and foam height 3.2 cm. the product did not cause skin irritation and exhibited strong antibacterial activity with an inhibition zone of 27.3 mm, exceeding the positive control asepsol (23.0 mm). therefore, solid soap formulated with cocok bubu leaf extract has great potential as a safe, effective, and environmentally friendly natural antibacterial product.