Metode RPTLC dan Optimasi Fase Gerak Dalam Penetapan Harga Rm Sebagai Salah Satu Parameter Lipofilisitas Dalam Rancangan Obat

Abstract

RPTLC and optimizing mobile phase methods in Rm value determination as one of lipophylicity parameters in drug design Background: The early process to successfully achieve its target is drug penetration or absorption. Of the three physicochemical parameters i.e, lipophyllicity, electronic and steric parameters, the lipophyllicity parameter is the most reponsible in drug absorption process. The research was aimed to determine retention modified (Rm) value of barbituric acid compound derivatives using RPTLC metod and mobile phase optimizing. Methods: This study was conducted on barbituric acid compound derivatives by using reverse phase thin layer chromatography (RPTLC). Silica Gel GF 254 that had been submerget in the mixture of liquid paraffin and petroleum eter (95:5) was used as a stationary phase. The mixture of polar to non polar solvent was used as mobile phase. Results: Research showed that in this method the most optimum of mobile phase was indicated by methanol and acetic acid mixture in the ratio of (1:9). The resulted Rm values of 5,5-diethylbarbituric acid, 5,5-diallylbarbituric acid, 5-allyl-5-isopropylbarbituric acid, 5-allyl-5-isobuthylbarbituric acid, 5-etil-5-(1-methylbutyl) barbituric acid, 5-(1-cyclohexene-1-yl)-1,5-dimethylbarbituric acid and 5-ethyl-5-phenylbarbituric acid were as follow 0.116; 0.144; 0.162; 0.221; 0.262; 0.187 and 0.199. Conclusions: The most optimum mobile phase in this method was the mixed solvents that had lower polarity, i.e, the mix of methanol and acetic acid in the ratio of (1:9). The H1 , H2 and H3 substituens in barbituric acid nuclei showed, the longer carbon chain, the higher the Rm values, howover the existing of double bond in such substituents will decrease the Rm value.