RESUMO
A stability-indicating assay procedure for the determination of norethindrone on the surface of Red Delicious apple slices was developed. The apple slice is homogenized in pH 10 borate buffer solution and norethindrone is then partitioned into chloroform using a diffusion chamber that has a membrane that is permeable to hydrophobic compounds separating the buffer and chloroform. An aliquot of the chloroform extract is then evaporated to dryness and reconstituted in tetrahydrofuran. The reconstituted sample is then chromatographed on a C18 reversed-phase column using a mobile phase consisting of water:tetrahydrofuran:methanol (63:26:11, v/v/v). Detection is in the UV range at 254 nm. The chromatographic system is specific for norethindrone in the presence of its autoxidation products. Stability data indicate that norethindrone is stable for up to 6 h on the surface of Red Delicious apples.
Assuntos
Frutas/análise , Noretindrona/análise , Cromatografia Líquida de Alta Pressão , Difusão , Estabilidade de Medicamentos , Concentração de Íons de Hidrogênio , Oxirredução , Soluções , Espectrofotometria UltravioletaRESUMO
A rapid, simple, stability-indicating assay procedure for norgestimate [(+)-13-ethyl-17-hydroxy-18,19-dinor-17 alpha-pregn-4-en-20-yn-3-one oxime acetate], a new progestational agent, and ethinyl estradiol (19-nor-17 alpha-pregna-1,3,5(10)-trien-20-yne-3,17-diol) in single- and composite-tablet analyses was developed using high-performance liquid chromatography. Norgestimate and ethinyl estradiol were extracted from the tablet matrix with methanol containing an internal standard. An aliquot was chromatographed on a 5-microns, reversed-phase column using water:tetrahydrofuran:methanol solution (65:25:10 v/v/v) as the mobile phase. The selectivity of the chromatographic system for intact norgestimate and ethinyl estradiol was demonstrated by resolving both compounds from various potential degradation products of each compound. An essential property of the chromatographic system was its ability to separate norgestimate as its syn and anti isomers. The method is linear, quantitative, and reproducible.
