title: Membrane permeability related physicochemical properties of a novel gamma-secretase inhibitor.
abstract: Pharmaceutical profiling studies were conducted on a novel prototype gamma-secretase inhibitor, to determine the potential of its oral absorption. Such compounds can be of use in the treatment of Alzheimer's disease (AD). The studies included determination of solubility, dissociation constant (pK(a)), octanol/water partition coefficient (log P) and the capacity factor (k'(IAM)) on immobilized artificial membrane (IAM) chromatographic columns. The compound is very slightly solubility in water (120 +/- 50 microg/mL) but the solubility increased considerably in basic medium (270 +/- 60 microg/mL). The compound exhibited pK(a) of (10.36 +/- 0.11); and log P of (3.36 +/- 0.16) determined by shake-flask method and (3.31 +/- 0.01) determined by high performance liquid chromatography (HPLC). The experimentally determined log P values correlated well with the calculated one of 3.44. The observed log k'(IAM) value of (2.79 +/- 0.04) indicates that the compound can reasonably be expected to have high membrane permeability, and therefore, good absorption profile if taken orally. This conclusion is also supported by other parameters determined.
authors.affiliation: Department of Pharmaceutical Sciences, Philadelphia College of Pharmacy, University of the Sciences in Philadelphia, Philadelphia, PA 19104, USA.
authors.forename: Ahmed M
authors.initials: AM
authors.lastname: El-Gendy
authors.forename: Adeboye
authors.initials: A
authors.lastname: Adejare
mesh_terms: D000042:Absorption; D000218:Adamantane / Q000031:analogs & derivatives* / Q000737:chemistry* / Q000493:pharmacokinetics* / Q000494:pharmacology; D000284:Administration, Oral; D053829:Amyloid Precursor Protein Secretases; D002463:Cell Membrane Permeability / Q000502:physiology*; D010450:Endopeptidases / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008956:Models, Chemical; D011480:Protease Inhibitors / Q000737:chemistry* / Q000493:pharmacokinetics*; D012995:Solubility; D013449:Sulfonamides / Q000737:chemistry* / Q000493:pharmacokinetics* / Q000494:pharmacology; D000096926:Benzenesulfonamides
chemical_list: D000218:Adamantane; D053829:Amyloid Precursor Protein Secretases; D010450:Endopeptidases; D011480:Protease Inhibitors; D013449:Sulfonamides; C494386:4-fluoro-N-(adamantan-2-yl)benzenesulfonamide; D000096926:Benzenesulfonamides