Predicting the oral absorption of a poorly soluble, poorly permeable weak base using biorelevant dissolution and transfer model tests coupled with a physiologically based pharmacokinetic model.

For predicting food effects and simulating plasma profiles of poorly soluble drugs, physiologically based pharmacokinetic models have become a widely accepted tool in academia and the pharmaceutical industry. Up till now, however, simulations appearing in the open literature have mainly focused on BCS class II compounds, and many of these simulations tend to have more of a "retrospective" than a prognostic, predictive character. In this work, investigations on the absorption of a weakly basic BCS class IV drug, "Compound A", were performed.

Precipitation in the small intestine may play a more important role in the in vivo performance of poorly soluble weak bases in the fasted state: case example nelfinavir.

The aim of this study was to evaluate the utility of biorelevant dissolution tests coupled with in silico simulation technology to forecast in vivo bioperformance of poorly water-soluble bases, using nelfinavir mesylate as a model compound. An in silico physiologically based pharmacokinetic (PBPK) model for poorly water-soluble, weakly basic drugs was used to generate plasma profiles of nelfinavir by coupling dissolution results and estimates of precipitation with standard gastrointestinal (GI) parameters and the disposition pharmacokinetics of nelfinavir. In vitro dissolution of nelfinavir mesylate film-coated tablets was measured in biorelevant and compendial media.

Biowaiver monographs for immediate release solid oral dosage forms: lamivudine.

Literature data relevant to the decision to allow a waiver of in vivo bioequivalence (BE) testing for the approval of immediate release (IR) solid oral dosage forms containing lamivudine as the only active pharmaceutical ingredient were reviewed. The solubility and permeability data of lamivudine as well as its therapeutic index, its pharmacokinetic properties, data indicating excipient interactions, and reported BE/bioavailability (BA) studies were taken into consideration. Lamivudine is highly soluble, but its permeability characteristics are not well-defined.

Biorelevant in vitro dissolution testing of products containing micronized or nanosized fenofibrate with a view to predicting plasma profiles.

The ability of in vitro biorelevant dissolution tests to predict the in vivo performance of nanosized fenofibrate (Lipidil 145 ONE®) and microsized fenofibrate (Lipidil - Ter®) was evaluated in this study. In vitro dissolution was carried out using USP apparatus 2 (paddle method) with updated biorelevant media to simulate the pre- and postprandial states. Membrane filters with different pore sizes were evaluated for their ability to hold back undissolved, nanosized drug particles.

The biowaiver procedure: its application to antituberculosis products in the WHO prequalification programme.

In 2005, the World Health Organization (WHO) proposed that provided an active pharmaceutical ingredient could meet certain criteria, bioequivalence could be evaluated with a set of laboratory tests, obviating the need for expensive and time-consuming pharmacokinetic studies in humans. The aim of this work was to determine whether this so-called "biowaiver" procedure can be applied to antituberculosis products. Antituberculosis products from the WHO Prequalification Programme, including three ethambutol, two isoniazid and one pyrazinamide product, were investigated.