PHARMACOKINETIC STUDY OF THE RELATIVE BIOAVAILABILITY AND BIOEQUIVALENCE AFTER ORAL INTENSIVE OR REPEATED SHORT-TERM TREATMENT WITH 2 POLYAMINO ACID FORMULATIONS

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-ar ginine) in association with vitamin B-12 (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 male s, 23 females), ranging in age from 23 to 32 years, were included in t he study. The pharmacokinetic behaviour of the various active ingredie nts was examined at a haematic level. Possible undesirable side-effect s, resulting from treatment, were also examined during the study. The mean pharmacokinetic constants considered (K(e1), C(max) and t1/2) gen erated an almost overlapping AUC (area under the curves) for all homol ogous components contained in both pharmaceutical forms. This indicate s almost complete bioequivalence. The mean index for the rate of relat ive bioavailability was, in fact, estimated to be 106.3 +/- 12.4%. Rep eated treatment did not appear to disturb the absorption mechanisms of the active ingredients contained in either of the two formulations ex amined, maintaining the relative bioavailability relationship within a negligible range, with a statistically non-significant difference (St udent's t test for coupled data). A few episodes, characterized by sli ght increases in excitability, were reported for both preparations in two patients (4%).