Understanding the degradation pathway of a poorly water-soluble drug formulated in PEG-400.

VX-497 is a poorly water-soluble compound. It is formulated in PEG-400 and encapsulated in softgel capsules. Although the drug product is stable at refrigerated conditions, many degradation peaks have been observed at accelerated storage conditions.

NMR structure of the enzyme GatB of the galactitol-specific phosphoenolpyruvate-dependent phosphotransferase system and its interaction with GatA.

The phosphoenolpyruvate-dependent carbohydrate transport system (PTS) couples uptake with phosphorylation of a variety of carbohydrates in prokaryotes. In this multienzyme complex, the enzyme II (EII), a carbohydrate-specific permease, is constituted of two cytoplasmic domains, IIA and IIB, and a transmembrane channel IIC domain. Among the five families of EIIs identified in Escherichia coli, the galactitol-specific transporter (II(gat)) belongs to the glucitol family and is structurally the least well-characterized.

Alterations in heart looping induced by overexpression of the tight junction protein Claudin-1 are dependent on its C-terminal cytoplasmic tail.

In vertebrates, the positioning of the internal organs relative to the midline is asymmetric and evolutionarily conserved. A number of molecules have been shown to play critical roles in left-right patterning. Using representational difference analysis to identify genes that are differentially expressed on the left and right sides of the chick embryo, we cloned chick Claudin-1, an integral component of epithelial tight junctions.

Physicochemical characterization and mechanisms of release of theophylline from melt-extruded dosage forms based on a methacrylic acid copolymer.

The purpose of the current study was to investigate the physicochemical properties of melt-extruded dosage forms based on Acryl-EZE and to determine the influence of gelling agents on the mechanisms and kinetics of drug release from thermally processed matrices. Acryl-EZE is a pre-mixed excipient blend based on a methacrylic acid copolymer that is optimized for film-coating applications. Powder blends containing theophylline, Acryl-EZE, triethyl citrate and an optional gelling agent, Methocel K4M Premium (hydroxypropyl methylcellulose, HPMC, hypromellose 2208) or Carbopol 974P (carbomer), were thermally processed using a Randcastle single-screw extruder.

Compression of controlled-release pellets produced by a hot-melt extrusion and spheronization process.

The purpose of this study was to investigate the physicomechanical and dissolution properties of tablets containing controlled-release pellets prepared by a hot-melt extrusion and spheronization process. A powder blend of anhydrous theophylline, Eudragit Preparation 4135 F, and functional excipients was melt-extruded, pelletized, and then spheronized. The pellets were compressed into tablets using forces of 5, 10, 15, and 20 kN.

NMR structural study of TcUBP1, a single RRM domain protein from Trypanosoma cruzi: contribution of a beta hairpin to RNA binding.

TcUBP1 is a trypanosome cytoplasmic RNA-binding protein containing a single, conserved RNA-recognition motif (RRM) domain involved in selective destabilization of U-rich mRNAs such as the Trypanosoma cruzi small mucin gene family mRNA, TcSMUG. TcUBP1 binds specific transcripts in vivo and co-localizes in the perinuclear part of the cell with components of the mRNA-stability determinant pathway such as poly(A)-binding protein 1 (PABP1) and TcUBP2, a closely related RRM-containing protein. In TcUBP proteins, the RRM domain is flanked by N-terminal Gln-rich and C-terminal Gly-Gln-rich extensions, which are involved in protein-protein interactions.

A novel powder coating process for attaining taste masking and moisture protective films applied to tablets.

A novel powder coating process was developed for the application of taste masking and moisture protective films on tablets while avoiding the use of solvents or water. The coalescence of particles to form a polymeric film was investigated through studies of dry powder layering of micronized acrylic polymer (E PO) to produce free films. Theophylline containing tablets were coated with the same acrylic polymer in a laboratory scale spheronizer using a powder coating technique.

Production of spherical pellets by a hot-melt extrusion and spheronization process.

Controlled-release theophylline containing spherical pellets were successfully produced by a hot-melt extrusion (HME) and spheronization process. A powder blend of anhydrous theophylline, Eudragit Preparation 4135 F, microcrystalline cellulose and polyethylene glycol 8000 powder was sieved, blended and then melt-extruded in a Randcastle Microtruder. The hot-melt extruded pellets were prepared by first cutting a thin, extruded composite rod into symmetrical pellets.