Reaction of substituted-aniline (8) with ethyl (l-methyl-5-nitroimidazole-2- carbonyl) acetate (9) gave 4-hydroxy-2-(l-methyl-5-nitro-2-imidazolyl)- substituted-quinolines (lo), which were converted to compound 11 with phosphorus oxychloride. Substituted-2-(l-methyl-5-nitro-2-imidazo1yl)-4.- methyl-(or phenyl-) quinolines (14) were prepared through the reaction of 2- acetyl-5-nitro-1-methy...

The nuclease stability and melting temperatures (Tm) were compared for fully modified oligoribonucleotide sequences containing 2'-fluoro, 2'-O-methyl, 2'-O-propyl and 2'-O-pentyl nucleotides. Duplexes formed between 2' modified oligoribonucleotides and RNA have typical A-form geometry as observed by circular dichroism spectroscopy. Modifications, with the exception of 2'-O-pentyl, were observed...

Isothiazolopyridines, pyridothiazines and pyridothiazepines are important compounds that possess valuable biological activities. This paper reports on the synthesis of these compounds using both conventional chemical methods and modern microwave techniques. 3-Bromo-6-hydroxy-4-methyl-2-thioxo-2,3-dihydropyridine-3-carboxamide, 5-arylazo-6-hydroxy-4-methyl-2-thioxo-1,2-dihydropyridine-3-carboxam...

Reaction between aromatic aldehydes and 3–methyl-1-phenyl-2-pyrazoline-5-one catalyzed by nano-SiO2/HClO4 in water under reflux provided a simple and efficient route for the synthesis of 4-((5-hydroxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)(aryl)methyl)-3-methyl-1-phenyl-1H-pyrazol-5-ol derivatives in high yields.

Reaction between aromatic aldehydes and 3–methyl-1-phenyl-2-pyrazoline-5-one catalyzed by nano-SiO2/HClO4 in water under reflux provided a simple and efficient route for the synthesis of 4-((5-hydroxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)(aryl)methyl)-3-methyl-1-phenyl-1H-pyrazol-5-ol derivatives in high yields.

Objective: The objective was formulation and characterization of low-density gastro-retentive microspheres of Acyclovir (ACV) using hydroxyl propyl methyl cellulose to enhanced retention time and bioavailability. Materials and Methods: HPMCK4M was used as polymer for forming microspheres and Poly Vinyl Alcohol as stabilizing agent. The microspheres were characterized with respect to their morph...

In the crystal structure of a semi-synthetic opioid drug buprenorphine, C29H41NO4 {systematic name: (2S)-2-[(5R,6R,7R,14S)-9α-cyclo-propyl-methyl-3-hy-droxy-6-meth-oxy-4,5-ep-oxy-6,14-ethano-morphinan-7-yl]-3,3-di-methyl-butan-2-ol}, the cyclo-propyl-methyl group is disordered over two sites with an occupancy factor of 0.611 (3) for the major component. One of the hy-droxy groups is involved in...

Transdermal drug delivery is an alternative route for systemic drug delivery which minimizes the absorption and increases the bioavailability. Orally Clopidogrel bisulfate has a short elimination half-life (7-8 hrs.), low oral bioavailability (50%) undergoes extensive first pass metabolism (85%) and frequent high doses (75 mg) are required to maintain the therapeutic level as a result, dose dev...

The present study was an attempt to formulate and evaluate enteric coated tablets for esomeprazole magnesium trihydrate. Different core tablets were prepared and formulation (F-1) was selected for further enteric coating, based on the disintegration time. Seal coating was applied to achieve 3% weight gain using opadry®. Enteric coating was carried out using different polymers like Eudragit L-30...

We present a multi-scale simulation method for modeling crystal growth in the presence of polymer excipients. The method includes a coarse-grained (CG) model for small molecules of known crystal structure whose force field is obtained using structural properties from atomistic simulations. This CG model is capable of stabilizing the molecular crystal structure and capturing the crystal growth f...