<![CDATA[Hair loss is characterized by a reduction in hair strands on the scalp. Biotin is a vitamin that can be used to stimulate hair growth. Microemulsions can increase the permeability of both hydrophobic and hydrophilic compounds as a delivery agent for nourishing and growing hair. The research was carried out experimentally to see. The research was carried out experimentally to see the physical quality tests and effectiveness of the optimum formula for biotin microemulsion as a hair tonic. The effectiveness test was carried out by applying the preparation to the rabbit's skin. The results of the physical quality test showed that the preparation had an organoleptic yellow color, was odorless and had a thick and homogeneous consistency. The pH test results had a value of 6.09, the viscosity test was 47.67 cPs and the particle size was 248.77 nm. Hair growth testing shows that the optimum formula for biotin microemulsion hair tonic can help hair grow up to 17.55 mm long for 21 days. The growth results were not significantly different from the positive control used. Stability testing showed no significant differences before and after storage, which means the preparation was stable during storage. Keywords: Biotin, Hair Tonic, Microemulsion, Hair Growth Abstrak Kerontokan rambut ditandai dengan berkurangnya helaian rambut di kulit kepala. Biotin adalah vitamin yang dapat digunakan untuk menstimulasi pertumbuhan rambut. Mikroemulsi dapat meningkatkan permeabilitas senyawa baik hidrofobik maupun hidrofilik sebagai penghantar zat aktif untuk menutrisi dan menumbuhkan rambut. Penelitian dilakukan secara eksperimental untuk melihat uji mutu fisik dan efektivitas formula optimum mikroemulsi biotin sebagai hair tonic. Uji efektivitas dilakukan dengan mengaplikasikan sediaan pada kulit kelinci. Hasil uji mutu fisik menunjukkan sediaan memiliki organoleptis berwarna kuning, tidak berbau dan konsistensi yang pekat serta homogen. Evaluasi lain menunjukkan hasil pengujian pH memiliki nilai 6,09, uji viskositas 47,67 cPs dan besar ukuran partikel 248,77 nm. Pengujian pertumbuhan rambut menunjukkan formula optimum hair tonic mikroemulsi biotin dapat membantu pertumbuhan rambut sepanjang 17,55 mm selama 21 hari. Nilai pertumbuhan tersebut tidak berbeda signifikan dengan kontrol positif yang digunakan. Data pengujian stabilitas menunjukkan tidak ada perbedaan yang signifikan sebelum dan sesudah penyimpanan yang berarti sediaan tersebut stabil selama penyimpanan. Kata Kunci: Biotin, Hair tonic, Mikroemulsi, Pertumbuhan Rambut]]>
