Microdetermination of ergocalciferol (vitamin D2) in pharmaceutical preparations by differential spectroscopy using trifluoroacetic acid in the absence of vitamin A.
A differential spectroscopy method for the determination of microgram quantities of ergocalciferol, using trifluoroacetic acid and hydrogen peroxide, was applied to commercially available pharmaceutical preparations. Tablets were powdered and extracted with methanol after being made basic with diethylamine. The methanol was concentrated, chloroform was added, and the mixture was chromatographed on neutral alumina using chloroform as the eluent. Ergocalciferol was determined in an aliquot of the eluate by differential spectroscopy and was compared with a reference ergocalciferol standard treated similarly. The method applied to low potency formulations (2.5-6 mug/tablet) is simple and quantitative, needs less than 5 hr for completion, and has a precision of less than +/- 2%. A simple and accurate chromatographic method for the determination of ergocalciferol in stabilized powders and high potency tablets, which precludes the necessity of solvent-solvent extraction, was also developed. The results are comparable with those obtained by the rat bioassay and the USP XVIII chemical assay.
Studies of the stability and extractability of vitamin D.
Abstract Radioactively labelled vitamin D 3 -4-C 14 was used as a tracer to study the in vitro degradation of vitamin D. Effects were noted of various environmental conditions such as temperature, dispersion into water, exposure to air, oxygen, and ultraviolet light, with chromatography on alumina and Fluoropak 80 being employed to evaluate destruction. Procedures which avoided potentially damaging environments are described for saponifying tissues and extracting them of vitamin D and possible metabolites. They consist basically of refluxing with KOH in methanol, extraction by organic solvents in the presence of adequate concentrations of alcohol, and partition prior to chromatography or radioactivity assay.
An Economic Analysis of Obesity in Europe: Health, Medical Care and Absenteeism Costs
Obesity is not only a health but also an economic phenomenon with potentially important direct and indirect economic costs that are unlikely to be fully internalized by the obese. In the US, obesity prevalence is the highest among OECD countries and the issue has long been the focus of policy debate and academic research. However, European obesity rates are rising and there is still a lack of economic analysis of the obesity phenomenon in Europe. This paper attempts to fill in this gap by using longitudinal micro-evidence from the European Community Household Panel to assess the importance of several costs of obesity in nine EU countries. The analysis provides nationally comparable estimates of the costs of obesity in terms of health, use of health care services and absenteeism.