USP Disintegration Apparatus as a Potential Tool for Evaluating Drug Release from Controlled-Release Dosage Forms

Official compendia lack in vitro dissolution guidelines for simulated fed conditions. The goal of this project was to compare disintegration times and drug release characteristics for Polygel CR tablets using USP dissolution Apparatus 1 and the USP disintegration apparatus. Calcium tablets plus vitamin D with different deaggregation properties were also used to study the food-weight effect on tablet disintegration. A USP disk, either flat or on its side, was placed on a tablet contained inside the USP disintegration apparatus to simulate the dosage form being in total contact with food after a heavy meal or in partial contact with food after a light meal, respectively. Drug release profiles for Polygel CR tablets in a simulated fasted state were not remarkably different whether the USP disintegration apparatus or USP dissolution Apparatus 1 was used (66.3 +/- 2.1% versus 55.3 +/- 1.3% in 6 h). Drug release, however, was observed to be higher in the simulated fed state when the USP disintegration apparatus with a disk was used (88.9 +/- 5.9% versus 47.5 +/- 0.8% in 6 h, p < 0.05). The data generated using calcium tablets plus vitamin D also suggest that food weight does not significantly accelerate the disintegration of tablets designed with rapid disintegration properties. However, the presence of a meal in the stomach may speed up the disintegration of slower disintegrating tablets

Evolution of genes and genomes on the Drosophila phylogeny

Comparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here for the first time (sechellia, simulans, yakuba, erecta, ananassae, persimilis, willistoni, mojavensis, virilis and grimshawi), illustrate how rates and patterns of sequence divergence across taxa can illuminate evolutionary processes on a genomic scale. These genome sequences augment the formidable genetic tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution. Despite remarkable similarities among these Drosophila species, we identified many putatively non-neutral changes in protein-coding genes, non-coding RNA genes, and cis-regulatory regions. These may prove to underlie differences in the ecology and behaviour of these diverse species