title: Pharmacokinetic study of the relative bioavailability and bioequivalence after oral intensive or repeated short term treatment with two polyamino acid formulations.
abstract: The authors studied the relative bioequivalence and bioavailability of two oral polyamino-acid formulations (packet and flacon), based on 4 amino acids (L-glutamine, L-phosphoserine, L-phosphothreonine and L-arginine) in association with vitamin B12 (Bio-logos, Sigma Tau Pharma S.A). Open-trial testing was carried out after intensive treatment and on the attainment of sustained levels. 50 healthy volunteers (27 males, 23 females), ranging in age from 23 to 32 years, were included in the study. The pharmacokinetic behaviour of the various active ingredients was examined at a haematic level. Possible undesirable side-effects, resulting from treatment, were also examined during the study. The mean pharmacokinetic constants considered (Ke1, Cmax and t1/2) generated an almost overlapping AUC (area under the curves) for all homologous components contained in both pharmaceutical forms. This indicates almost complete bioequivalence. The mean index for the rate of relative bioavailability was, in fact, estimated to be 106.3 +/- 12.4%. Repeated treatment did not appear to disturb the absorption mechanisms of the active ingredients contained in either of the two formulations examined, maintaining the relative bioavailability relationship within a negligible range, with a statistically non-significant difference (Student's t test for coupled data). A few episodes, characterized by slight increases in excitability, were reported for both preparations in two patients (4%).
authors.affiliation: Institute of Pharmacology, Faculty of Medicine and Surgery, University of Catania, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Matera
authors.forename: R
authors.initials: R
authors.lastname: Castana
authors.forename: L
authors.initials: L
authors.lastname: Insirello
authors.forename: G
authors.initials: G
authors.lastname: Leonardi
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000596:Amino Acids / Q000009:adverse effects / Q000493:pharmacokinetics*; D001120:Arginine / Q000493:pharmacokinetics; D001682:Biological Availability; D004334:Drug Administration Schedule; D005260:Female; D005569:Formularies as Topic; D005973:Glutamine / Q000493:pharmacokinetics; D006801:Humans; D008297:Male; D010768:Phosphoserine / Q000493:pharmacokinetics; D010769:Phosphothreonine / Q000493:pharmacokinetics; D013810:Therapeutic Equivalency; D014805:Vitamin B 12 / Q000009:adverse effects / Q000493:pharmacokinetics
chemical_list: D000596:Amino Acids; D005973:Glutamine; D010769:Phosphothreonine; D010768:Phosphoserine; D001120:Arginine; D014805:Vitamin B 12