Lymphocyte P-glycoprotein variability in healthy individuals.

The aim of the present work was to describe the distribution of lymphocyte P-glycoprotein activity on a population of healthy individuals, taking also into account sex and age. P-glycoprotein activity in lymphocytes was measured by the Rhodamine 123 efflux assay using flow cytometry, in the presence and absence of verapamil, a P-glycoprotein inhibitor. We obtained a range of P-glycoprotein activity from 1.

Importance of entero-salivary recirculation in paracetamol pharmacokinetics.

The contribution of an entero-salivary recirculation (salivary secretion-swallowed-reabsorption of drug from the gastrointestinal tract) to the values of the pharmacokinetic parameters of paracetamol was studied in a two-way crossover design. Five healthy volunteers took a tablet of Paracetamol (500 mg) in two occasions separated by a washout period. The difference between the two treatments consisted of saliva that was allowed or not to be swallowed during the 4 h of study.

Comparison of two compartmental models for describing ranitidine's plasmatic profiles.

The plasmatic profiles of 12 healthy volunteers after oral administration of ranitidine (150 mg) were studied considering two compartmental models. We observed the presence of two peaks. The proposed mechanism responsible for the existence of secondary peaks includes enterohepatic recirculation and the existence of multiple sites of absorption along the gastrointestinal tract.

Robust methods in bioequivalence assay; preliminary results.

The aim of this study is to compare four statistical methods for outlier identification in Bioequivalence tests. The methods are based in four confidence intervals, 'parametric','non- parametric','robust with the asymptotic distribution of the M-estimator' and 'robust with the bootstrap distribution'. The drug we used was Diltiazen, in a two sequence randomized crossover study design.