title: Differences in the bioavailability of dihydrotachysterol preparations.
abstract: The bioavailability of four preparations containing dihydrotachysterol (DHT2) was tested in two separate trials with administration of single, oral doses of 1 mg per individual. The relative bioavailability of corresponding preparations (capsules vs capsules and oral solution vs oral solution) was tested in a randomised, cross-over pattern within the same group of volunteers. Two different groups of 24 healthy volunteers took part in each trial. Solution and capsule bioavailability was also compared inter-individually. A new sensitive HPLC-method (quantification limit 0.5 ng.ml-1) was used for the measurement of DHT2 concentration in serum. Three of the preparations tested had a similar bioavailability (mean AUC values of 195.5-223 ng.h.ml-1); the bioavailability of the fourth preparation (A.T.10 oral solution) was considerably lower (mean AUC value 111.5 ng.h.ml-1). The present dosage recommendations of all four preparations are identical. A new dosage recommendation is thus required for the oral solution with low bioavailability (A.T.10).
authors.affiliation: Pharmacological Research Company Biopharm GmbH, Berlin, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Koytchev
authors.forename: R G
authors.initials: RG
authors.lastname: Alken
authors.forename: M
authors.initials: M
authors.lastname: Vagaday
authors.forename: U
authors.initials: U
authors.lastname: Kunter
authors.forename: V
authors.initials: V
authors.lastname: Kirkov
mesh_terms: D000328:Adult; D001682:Biological Availability; D002214:Capsules; D002851:Chromatography, High Pressure Liquid; D018592:Cross-Over Studies; D004097:Dihydrotachysterol / Q000493:pharmacokinetics*; D005260:Female; D006801:Humans; D008297:Male; D012996:Solutions
chemical_list: D002214:Capsules; D012996:Solutions; D004097:Dihydrotachysterol