Determination of Norgestimate in Serum by Automated High-Performance Liquid Chromatography and Subsequent Radioimmunoassay

Stability-indicating high-performance thin-layer chromatographic determination of levonorgestrel and ethinyloestradiol in bulk drug and in low-dosage oral contraceptives

A stability-indicating high-performance thin-layer chromatography (HPTLC) method was developed and validated for simultaneous determination of steroidal hormones levonorgestrel and ethinyloestradiol both in bulk drug and in low-dosage oral contraceptives. Optimization of conditions for the spectrodensitometric procedure was reached by eluting HPTLC silica gel plates in a 10 cm x 10 cm horizontal chamber. The solvent system consisted of hexane-chloroform-methanol (1.0:3.0:0.25, v/v/v). This system was found to give compact, dense and typical peaks for both levonorgestrel (R(f)=0.65+/-0.03) and ethinyloestradiol (R(f)=0.43+/-0.02). Densitometric analysis of the drugs was carried out in the reflectance mode at 225 nm by using a computer controlled densitometric scanner. The calibration curves of levonorgestrel and ethinyloestradiol were linear in the range of 200-800 and 40-160 ng per spot, respectively. The method was validated for precision, robustness and recovery. As the proposed method can effectively separate the drugs from their degradation products, it can be employed as a stability-indicating method.

Determination of steroid hormones in oral contraceptives by high-performance liquid chromatography

The aim of this research was to standardize a high-performance liquid chromatographic method for quantitative determination of steroid hormones, like ethinylestradiol (ETE), levonorgestrel (LEVO), and gestodene (GEST), in commercially available oral contraceptives (OCs). The combination ETE-LEVO was analyzed using a LiChrospher 100 RP-8 column (5 microns, 125 x 4 mm) in LiChroCART, with a mobile phase constituted of acetonitrile: water (60:40 v/v). Using the same column, ETE-GEST was analyzed with a mobile phase constituted of acetonitrile:water (50:50 v/v) at pH 7.5 adjusted with 0.02 M ammonium hydroxide. For both methods, a flow rate of 0.8 mL/min was utilized and detection was carried out at 215 nm. All analyses were performed at room temperature (24 +/- 2 degrees C). Calibration curves for ETE-LEVO were obtained using solutions with concentration ranges from 2.40 to 60.0 micrograms/mL (ETE), and from 12.0 to 300.0 micrograms/mL (LEVO). Calibration curves for ETE-GEST were obtained using solutions with concentration ranges from 2.40 to 60.0 micrograms/mL (ETE), and from 9.0 to 160.0 micrograms/mL (GEST). Correlation coefficients obtained were from 0.9999 to 0.9990. Coefficients of variation for samples containing ETE-LEVO were 0.47% and 0.38%, respectively. For samples with ETE-GEST they were 0.39% and 0.44%, respectively. The average recovery for samples with ETE-LEVO was 103.46% and 100.78%, respectively. For samples containing ETE-GEST it was 100.89% and 101.03%, respectively.

Determination of norgestimate and its metabolites in human serum using high-performance liquid chromatography with tandem mass spectrometric detection

A rapid and reliable analytical method is described for the simultaneous determination of a synthetic progestin norgestimate (NGM), and its metabolites, 17-deacetylnorgestimate (17-DA-NGM), 3-ketonorgestimate (3-keto-NGM) and norgestrel (NGL) in human serum using reversed phase high-performance liquid chromatography (HPLC) with tandem mass spectrometric (MS-MS) detection. The assay was linear over the concentration ranges of 0.1-5.0 ng/ml for 17-DA-NGM and NGL and 0.5-5.0 ng/ml for NGM and 3-keto-NGM. The inter-assay reproducibility was consistently less than 10%. The overall recovery of the analytes ranged from 72 to 92%. Serum profiles following oral administration of norgestimate to female volunteers are presented.