JOURNAL OF COSMETIC SCIENCE 420 prepared by using sorbitan sesquioleate (HLB = 3.70) and polysorbate 60 (HLB = 14.90). Evaluation of turbidity using a UV-vis spectrophotometer and a turbidity meter (Lutron) showed a similar tendency. The required HLB values for maximum turbidities of CUFO, CUPO, HF, and CJSO O/W emulsions were measured as 14.90, 14.90, 7.06, and 5.94, respectively. The CUFO and CU PO emulsions had the highest turbidity at the highest HLB value of 14.90. Therefore, CUFO and CUPO needed additional experiments with polysorbate 20 (HLB = 16.70), considering the required HLB value higher than 14.90. From the additional experiments, the CUFO emulsion exhibited the highest turbidity and minimum droplet size at HLB values of 14.75–14.90. The CUPO Figure 12. Mean droplet size variations of emulsions of liquid paraffi n in the HLB range 3.70–14.90 (n = 3 ±SD). Figure 11. Turbidities of CUFO, CUPO, HF, and CJSO emulsions in HLB range 3.70–14.90 which was measured by a turbidity meter after 1 week storage at room temperature (n = 3 ±SD).

DETERMINATION OF REQUIRED HLB VALUE 421 emulsion had the highest turbidity and minimum droplet size at HLB values of 15.35–15.40. To confi rm whet her the additional experiments using polysorbate 20 shows the same tendency as the previous experiments, the experiments were conducted using HF and CJSO emulsions. The HF and CJSO emulsions had the maximum turbidity and the minimum droplet size at an HLB value of 6.30. By measuring th e turbidity [UV-vis spectrophotometer and turbidity meter (Lutron)] and droplet size (particle size analyzer) of each prepared O /W emulsion, fi nally the re- quired HLB values for the CUFO, CUPO, HF, and CJSO were found to lie within 14.75– 14.90, 15.35–15.40, 6.30–7.04, and 5.94–6.30, respectively. Figure 14. Mean droplet size variation of emulsions of HF in the HLB range 3.70–14.90 (n = 3 ±SD). Figure 13. Mean droplet size variations of emulsions of CUFO, CUPO, and CJSO in the HLB range 3.70– 14.90 (n = 3 ±SD).