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Biomedical subjects

M Hidiroglou

Publications and source records attributed to M Hidiroglou.

143 records · Page 8Linked to original sources
PubMedDate not supplied

Comparison of vitamin C bioavailability after multiple or single oral dosing of different formulations in sheep.

The purpose of this study was to compare the bioavailability of either multiple or single oral supplementation of different formulations of vitamin C and intra-duodenal supplementation of one form of vitamin C in sheep. Formulations used in the study were (1) ascorbic acid fine powder (AA); (2) ascorbic acid coated with ethyl cellulose (EC); (3) Rovimix STAY-C (SC); (4) sodium ascorbate (SA); (5) Rovimix C (RC). The bioavailability of vitamin C formulations was assessed by the changes in plasma ascorbic acid concentrations, area under the curve (AUC) and area under the curve above its basal concentration (AUCabove) values. There was no effect of single oral supplementation on bioavailability of vitamin C. Multiple dosing over a period of 28 days of oral supplementation of all five formulations resulted in higher AUCabove values. Furthermore, multiple oral supplementation of RC increased plasma concentrations of ascorbic acids and AUC values. Single intra-duodenal supplementation of ascorbic acid resulted in significantly higher AUC when compared with oral supplementation of the same vitamin C.

Administration, Oral↗
PubMedDate not supplied

Liquid chromatographic cleanup and determination of low levels of vitamin D3 in sheep plasma.

A liquid chromatographic (LC) method is described for the determination of vitamin D3 in sheep plasma. Samples are extracted by one of 2 different methods, depending on the concentration of vitamin D3. The samples are purified by using either a Sep-Pak silica cartridge or a small alumina column, followed by additional cleanup on a Metalsorb LC column. Final analysis was carried out on a 5 micron C18 column using a radial compression separation system with an acetonitrile-methanol solvent system. Vitamin D3 was completely resolved from any interfering compounds in the plasma; total run time was less than 15 min, using a variable wavelength detector set at 264 nm. The method was successfully applied to samples at levels of 1-10 ng added vitamin D3 mL sheep plasma, with recoveries in the range 90-97%.

Animals↗