title: Amobarbital interactions with 25-hydroxycholecalciferol: effects on the extraction, quantification, and competitive protein binding in vitro.
abstract: Amobarbital has been found to coelute with 25-hydroxycholecalciferol (25OHD3) on a normal phase high performance liquid chromatographic system and cause subsequent interference in the UV detection and plasma transport competitive protein binding assay for this vitamin D metabolite. Concentrations of 25OHD3 were overestimated by 95% in the presence of 0.4 mg amobarbital in the competitive protein binding assay; as little as 0.1 mg amobarbital caused a 22% overestimation in the concentration of 25OHD3 in the assay. Separation of 25OHD3 from amobarbital on a reverse phase high performance liquid chromatographic system allowed for proper quantification without interference. Because of the similarity of chemical structures, other barbital-based compounds may cause similar interactions with 25OHD3 or other vitamin D metabolites as well.
mesh_terms: D000654:Amobarbital / Q000097:blood*; D000818:Animals; D001667:Binding, Competitive; D002112:Calcifediol / Q000097:blood* / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid; D066298:In Vitro Techniques; D011485:Protein Binding / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D000654:Amobarbital; D002112:Calcifediol