Optimization of Gelling Agent and Sunscreen Activity Test of 4-OH-chalcone Gel by In Vitro Method

ABSTRACT The 4-OH-chalcone was suspected to absorb and reduce ultraviolet radiation intensity that exposed to the skin. The 4-OH-chalcone was formulated as gel dosage form using combination of carbopol in content of 0.50-1.00% w/w; propylene glycol in content of 19-20% w/w; and CMC-Na in content of 0.50-1.00% w/w. This study’s purpose was to optimize the three gel bases, evaluate physical properties, physical stability, and activity of 4-OH-chalcone gel as sunscreen by in vitro method. Simplex Lattice Design (SLD) method was used to optimize gel base with Design Expert software version 10.0. Activity of 4-OH-chalcone gel as sunscreen was determined spectrophotometrically by determining Sun Protecting Factor (SPF) value, percent transmission of erythema (% TE), and percent transmission of pigmentation (% TP). Data were analyzed statistically with SPSS Statistic software. Optimum formula of 4-OH-chalcone gel with 0.50% w/w carbopol content, 0.50% w/w carboxymethylcellulose sodium content, and 20,0% w/w propylene glycol content has pH of 5.59, viscosity of 37.4 dPa.s, spreadability of 28.8 cm2, adhesive time of 1.28 seconds, SPF value of 28.65, %, TE value of 16.44%, %TP value of 0.24%, and relatively stable physical properties.