Regional-Dependent Intestinal Permeability and BCS Classification: Elucidation of pH-Related Complexity in Rats Using Pseudoephedrine
Journal Title: The AAPS Journal - Year 2013, Vol 15, Issue 2
Abstract
Based on its lower Log P value relative to metoprolol, a marker for the low/high-permeability (Peff) class boundary, pseudoephedrine was provisionally classified as BCS low-permeability compound. On the other hand, following oral administration, pseudoephedrine fraction dose absorbed (Fabs) and systemic bioavailability approaches 100%. This represents a challenge to the generally recognized Peff–Fabs correlation. The purpose of this study was to elucidate the underlying mechanisms behind the confusion in pseudoephedrine’s BCS classification. Pseudoephedrine’s BCS solubility class was determined, and its physicochemical properties and intestinal permeability were thoroughly investigated, both in vitro and in vivo in rats, considering the complexity of the whole of the small intestine. Pseudoephedrine was found to be unequivocally a high-solubility compound. All of the permeability studies revealed similar phenomenon; at any given intestinal segment/pH, the permeability of metoprolol was higher than that of pseudoephedrine, however, as the intestinal region becomes progressively distal, and the pH gradually increases, pseudoephedrine’s permeability rises above that of metoprolol in the former segment. This unique permeability pattern likely explains pseudoephedrine’s complete absorption. In conclusion, pseudoephedrine is a BCS Class I compound; no discrepancy between Peff and Fabs is involved in its absorption. Rather, it reflects the complexity behind Peff when considering the whole of the intestine. We propose to allow high-permeability classification to drugs with Peff that matches/exceeds the low/high class benchmark anywhere throughout the intestinal tract and not restricted necessarily to the jejunum.
Authors and Affiliations
Moran Fairstein, Rotem Swissa, Arik Dahan
Keywords
Related Articles
- EP ID EP681108
- DOI 10.1208/s12248-013-9462-x
- Views 79
- Downloads 0
Encapsulation of water-insoluble drug by a cross-linking technique: Effect of process and formulation variables on encapsulation efficiency, particle size, and in vitro dissolution rate
Ibuprofen-gelatin micropellets were prepared by the cross-linking technique using formaldehyde. Spherical micropellets having an entrapment efficiency of 65% to 85% were obtained. The effect of core to coat ratio, speed...
Characterization of Nanoporous Surfaces as Templates for Drug Delivery Devices
Bare silicon wafers, gold-coated silicon wafers, and nanoporous gold-coated silicon wafers were obtained from Nanomedsystems, Charlottesville, VA, USA (formerly Setagon, Inc.). A bare metal stent (Palmaz-Schatz®...
Discovery pharmaceutics—Challenges and opportunities
Most pharmaceutical companies are now evaluating compounds for druglike properties early in the discovery process. The data generated at these early stages allow upfront identification of potential development challenges...
Topical Ocular Delivery of NSAIDs
In ocular tissue, arachidonic acid is metabolized by cyclooxygenase to prostaglandins which are the most important lipid derived mediators of inflammation. Presently nonsteroidal anti-inflammatory drugs (NSAIDs) which ar...
Emerging Applications of Metabolomics in Studying Chemopreventive Phytochemicals
Phytochemicals from diet and herbal medicines are under intensive investigation for their potential use as chemopreventive agents to block and suppress carcinogenesis. Chemical diversity of phytochemicals, together with...