The combination of fluticasone propionate (FLP) and salmeterol (SAL) is often used in clinical practice for the treatment of pulmonary disorders. The purpose of this study was to explore the pharmacokinetics (PK) of inhaled FLP and SAL, after concomitant administration, in healthy male and female subjects using two dry powder inhalers. Plasma concentration (C)-time (t) data were obtained from a single dose, two-sequence, two-period, crossover (2 x 2) bioequivalence (BE) study. Activated charcoal was co-administered in order to prohibit absorption from the gastrointestinal tract. A number of 60 subjects were recruited, while 57 of them completed the study and were included in the PK analysis. Initially, PK parameters of FLP and SAL were estimated using the classic non-compartmental methods. Subsequently, BE assessment was applied to the estimated PK parameters of the two dry powder inhalers. Special focus was placed on the population PK analysis of the C-t data, which were pooled together. `Treatment' (i.e., test or reference) and `period' of the BE study were considered as covariates. A variety of structural and residual error models were tested to find the one which best described the plasma C-t data of FLP and SAL. Demographic data were also evaluated for their impact on the PK parameters. Several goodness-of-fit criteria were utilized. The non-compartmental PK estimates of this study were in agreement with previously reported values. The population PK analysis showed that FLP data were described by a two compartment model with first-order absorption and elimination kinetics. Body weight was found to affect significantly absorption rate constant, inter-compartmental clearance, and volume of distribution of the peripheral compartment. As body weight increases, the values of these PK parameters also rise. For SAL, the best results were obtained when a two-compartment disposition model was used assuming very rapid absorption kinetics (like intravenous bolus) and first-order elimination kinetics. Gender was found to be a significant covariate on clearance, with men exhibiting higher clearance than women. (C) 2015 Elsevier B.V. All rights reserved.

In the case of pediatric medicinal products the selection of an appropriate and palatable liquid dosage form can make the difference between treatment success and failure. Since the recent adoption of Pediatric Regulations in the U.S. and E.U., there is a greater demand for age-appropriate medicines for children. Extended research on the use of milk on drug administration in pediatric population has shown the multiple benefits of its use. Milk exhibits great solubilizing, gastroprotective and taste masking properties, which are very important characteristics in the case of insoluble, irritating and bitter-tasting active compounds. Milk-based formulations rely on a novel, simple and user-friendly approach for the delivery of ionized and unionized lipophilic drugs. In parallel they can provide critical nutritive elements and a wide range of biologically active peptides, very important elements especially for pediatric patients. (C) 2015 Elsevier B.V. All rights reserved.

This work discusses the scientific aspects of the definition of dose as the `highest single oral IR dose' recommended for administration in the SmPC (summary of product characteristics) in the current European Medicines Agency (EMA) 2010 Guideline, for the purpose of biopharmaceutics classification system (BCS)-based biowaiver decision making. Analysis of theoretical and experimental data dealing with drug dissolution and biopharmaceutic drug classification reveals that the drug dose is an important parameter for both drug dissolution and biopharmaceutic classification. The relevant implications for the dose considerations in bioequivalence studies are also discussed briefly. It is suggested that the concept of ``the highest single dose oral IR dose recommended for administration in the SmPC{''} of the EMA 2010 Guideline be abolished. It is advisable, each dose strength be considered separately Le., whether or not it meets the solubility-dissolution regulatory criteria. (C) 2014 Elsevier B.V. All rights reserved.