A novel megestrol acetate electrochemical sensor based on conducting functionalized acetylene black-CeO2NPs nanohybrids decorated glassy carbon microspheres.

For the first time, megestrol acetate (MGA), a synthetic progestin with therapeutic use in breast cancer, is electrochemically studied to propose a new electroanalytical alternative for its detection in real samples. In the present work, a novel electrochemical sensor based on functionalized acetylene black-CeO2NPs nanohybrids modified glassy carbon microspheres paste electrode (FAB-CeO2NPs/GCMPE) was successfully fabricated and used for sensitive determination of MGA. The modified electrode has been characterized using scanning electron microscope (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The electrocatalytic reduction of MGA using FAB-CeO2NPs/GCMPE was carried out via CV and square wave voltammetry (SWV). By employing FAB-CeO2NPs/GCMPE, the SWV signal of MGA reduction was 8 fold higher than the bare GCMPE. A wide concentration range from 4.20 × 10-8 to 1.13 × 10-6 M with the low LOD of 1.30 nM for MGA was achieved. The practical analytical utilities of the prospective FAB-CeO2NPs/GCMPE sensor were demonstrated successfully by the detection of MGA in Megace tablets, human serum and urine samples obtained from healthy and patient volunteers after oral administration of 160 mg Megace tablets. HPLC method was also developed for comparison with the electroanalytical method.

Development and validation of a high performance liquid chromatography method for determination of 6-benzyl-1-benzyloxymethyl-5-iodouracil (W-1), a novel non-nucleoside reverse transcriptase inhibitor and its application to a pharmacokinetic study in rats.

A sensitive and selective high-performance liquid chromatographic (HPLC) method for determination of 6-benzyl-1-benzyloxymethyl-5-iodouracil (W-1), a novel non-nucleoside reverse transcriptase inhibitor in rat plasma, was developed and validated. Chromatographic separation of W-1 and megestrol acetate (internal standard) was achieved on a reversed-phase C18 column at 25°C. The mobile phase was consisted of acetonitrile-water (60:40, v/v) and pumped at a flow rate of 1.0 mL/min. The ultraviolet (UV) detector was set at the absorption wavelength of 284 nm. The calibration curve for W-1 was linear over the concentration range of 0.01-8 µg/mL and the lower limit of quantification was 10 ng/mL. The intra- and inter-day precision and accuracy were <8.9 and 5.3%, respectively. The extraction recoveries ranged from 97.9 to 101.6%. The validated HPLC method was successfully applied to a pharmacokinetic study of W-1 in rats.

[Study on simultaneous determination method for banded synthesis hormones residues in egg products].

OBJECTIVE: To develop method of 7 banded synthesis sex hormones residues in egg products determined by ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). METHODS: The sample were enzymolied and target compounds were extracted with methanol. ZnCl2 was added to the extract solution to remove lipid and then analytes were purified by LC-C18 and LC-NH2 solid phase extraction cartridge and further determined by UPLC-MS/MS under positive ionization and multiple reaction monitoring (MRM) modes. RESULTS: The limits of detection (LOD) of UPLC-MS/MS method used for testing Chlormadione acetate (CDA), Medroxypogesterone acetate (MPA), Megestrol Acetate (MA), Testosterone propionate (TSP), Norgestrel (NG), Methyltestosterone (MTS) and Nandrolone (NT) in egg products ranged from 0.012 to 0.23 microg/kg, and the limits of quantification (LOQ) were from 0.04 to 0.76 microg/kg. Experiments on spiked samples of egg products showed that at addition level of 2.0 microg/kg, the average recoveries of the sex hormones ranged from 80.2% to 114%, and coefficients of variation from 6.7% to 14.3%; while at addition level of 4.0 microg/kg, the average recoveries ranged from 75% to 119%, and coefficient of variation from 2.9% to 7.3%. CONCLUSION: The method could be able to identify and quantify banded synthesis hormones residues in eggs and egg products. It could be simple and sensitive, suitable for statutory residue testing.

Determination of gestagens in kidney fat by liquid chromatography tandem mass spectrometry.

The use of gestagens in animal fattening is prohibited within the European Union. Recently, the use of spectrometric methods for the detection and confirmation of banned substances was made obligatory. Therefore, conventional high-performance liquid chromatographic (HPLC) methods have been superseded. It has been possible to couple a previously described HPLC method for the determination of acetyl-gestagens in kidney fat to tandem mass spectrometry (LC-MS/MS). The decision limits CCalpha and the detection capability CCbeta are found to be below the minimum required performance limit (MRPL) established for medroxyprogesterone acetate (MPA) at 1 microg kg(-1). The calculated values for CCalpha are as follows: megestrol acetate (MGA)--0.15 microg kg(-1), melengesterol acetate (MLA)--0.15 microg kg(-1), chlormadinone acetate (CMA)--0.37 microg kg(-1) and for medroxyprogesterone acetate (MPA)--0.24 microg kg(-1). The CCbeta values for these compounds have been determined as 0.19, 0.19, 0.47 and 0.32 microg kg(-1), respectively.

Characterization of related impurities in megestrol acetate.

Three new compounds, 17alpha-acetoxy-2,6-dimethylpregna-1,4,6-triene-3,20-dione (1), 17alpha-acetoxy-2alpha,6-dimethylpregna-4,6-diene-3,20-dione (2), 17alpha-acetoxy-6alpha-methoxylmethylpregna-4-ene-3,20-dione (3), together with five known ones, 17alpha-acetoxy-6beta-hydroxyl-6alpha-methylpregna-4-ene-3,20-dione (4), 17alpha-acetoxy-6alpha-hydroxyl-6beta-methylpregna-4-ene-3,20-dione (5), 17alpha-acetoxy-pregna-4-ene-3,6,20-trione (6), 17alpha-acetoxy-pregna-4-ene-3,20-dione (7) and 17alpha-acetoxy-6-methylene-pregna-4-ene-3,20-dione (8), were isolated and identified from the residual mother liquor of megestrol acetate. Their structures were established by spectroscopic methods. These compounds seem to be minor impurities in production of the drug megestrol acetate.

Nutrición y SIDA / Nutrition and AIDS

La infección por el VIH en la infancia es un importante problema sanitario. Se calcula que cada año nacen 400-600 hijos de madres seropositivas.El diagnóstico precoz de la infección por el VIH en el niño, es de gran importancia para instaurar lo antes posible tratamiento antirretroviral, profilaxis de infecciones oportunistas, inmunización activa y pasiva, así como un soporte psicosocial y nutricional adecuado.Estos niños presentan una disregulación en el metabolismo de las citocinas que parecen jugar un importante papel en la malnutrición, la cual es de etiología multifactorial y puede presentarse en cualquier momento evolutivo de la enfermedad.Sería importante determinar los índices nutricionales con mayor poder discriminativo para valorar la malnutrición; pues se ha encontrado una correlación entre el deterioro de la situación clínica, inmunológica y nutricional.Las nuevas estrategias terapéuticas de la desnutrición en niños con infección por VIH, se basan en la administración de acetato de megestrol y hormona de crecimiento cuyo efecto parece ser beneficioso (AU)

Liquid chromatographic determination of progestogens in animal fat.

A liquid chromatographic method was developed for determination of 3 progestogens-melengestrol acetate, megestrol acetate, and chlormadinone acetate-found in edible tissue at concentrations between 10 and 1000 ppb. These progestogens are commonly used as feed additives to control herd estrus and to improve feed efficiency. Rendered fat was extracted with acetonitrile, washed with hexane, and dried. The remaining lipids were saponified with sodium hydroxide and precipitated with magnesium chloride. The progestogens were extracted from the basic solution with hexane, dried, and cleaned up on a cyanopropyl solid-phase extraction column in the normal-phase mode. The eluate was dried and reconstituted with acetonitrile-water (7 + 3, v/v). Chromatography was performed on a 5 microns high-carbon load C18 column with acetonitrile-water (7 + 3, v/v) at 1 mL/min and UV detection at 291 nm. Recoveries from fortified samples ranged from 84 to 116%. The limit of quantitation was 10 ppb for both beef and pork. The detection limit was 3 ppb.