Government College

About: Government College is a based out in . It is known for research contribution in the topics: Population & Ring (chemistry). The organization has 4481 authors who have published 5986 publications receiving 57398 citations.

Fluoride removal study using pyrolyzed delonix regia pod, an unconventional adsorbent

Abstract: Applicability of the new material pyrolyzed Delonix regia pod carbon for the removal of excess fluoride ions from the water that harm the human and the environment was studied. The adsorbent was characterized both physically and chemically. Surface chemistry characterization was done with pH-drift method. Batch adsorption studies were carried out for the effect of pH, dosage, contact time, initial fluoride concentration, temperature and interfering co-ions. The physicochemical properties and textural characters were analyzed. Equilibrium data were studied using Freundlich, Langmuir, Temkin and Dubinin–Radushkevich models, in which Freundlich isotherm was considered to be the best fit for the adsorbent. The sorption nature was studied using thermodynamic parameters which showed spontaneous, irreversible, stable and endothermic. The adsorption kinetics follows pseudo-second order. The mechanism of adsorption was determined from intraparticle diffusion model. Boyd plot showed that the adsorption of fluoride on the carbon was mainly governed by particle diffusion.

Review of insulin and its analogues in diabetes mellitus

Abstract: Diabetes is a metabolic disorder where in human body does not produce or properly uses insulin, a hormone that is required to convert sugar, starches and other food into energy. Diabetes finally leads to more complications and to prevent these complications insulin and its analogues are used. After more than half a century of treating diabetics with animal insulin's, recombinant DNA technologies and advanced protein chemistry made human insulin preparations available in the early 1980s. As the next step, over the last decade, insulin analogues were constructed by changing the structure of the native protein with the goal of improving the therapeutic properties of it, because the pharmacokinetic characteristics of rapid, intermediate and long-acting preparations of human insulin make it almost impossible to achieve sustained normoglycemia. The first clinically available insulin analogue, lispro, confirmed the hopes by showing that improved glycaemic control can be achieved without an increase in hypoglycaemic events. Two new insulin analogues, insulin glargine and insulin aspart, have recently been approved for clinical use in the United States and several other analogues are being intensively tested.

Synthesis and characterization of palladium(II) complexes of thioureas. X-ray structures of [Pd(N,N′-dimethylthiourea)4]Cl2 · 2H2O and [Pd(tetramethylthiourea)4]Cl2

Abstract: Palladium(II) complexes of thiones having the general formula [Pd(L)4]Cl2, where L = thiourea (Tu), methylthiourea (Metu), N,N′-dimethylthiourea (Dmtu), and tetramethylthiourea (Tmtu) were prepared by reacting K2[PdCl4] with the corresponding thiones. The complexes have been characterized by elemental analysis, IR and NMR spectroscopy, and two of these, [Pd(Dmtu)4]Cl2 · 2H2O (1) and [Pd(Tmtu)4]Cl2 (2), by X-ray crystallography. An upfield shift in the >C=S resonance of thiones in 13C NMR and downfield shift in N–H resonance in 1H NMR are consistent in showing sulfur coordination with palladium(II). The crystal structures of the complexes show a square-planar coordination environment around the Pd(II) ions with the average cis and trans S–Pd–S bond angles of 89.64° and 173.48°, respectively.

Development and Characterization of Zaleplon Solid Dispersion Systems: A Technical Note

Abstract: Zaleplon (Fig. 1) is a pyrrazolopyrimidine hypnotic drug indicated for the short term (2 to 4 weeks) management of insomnia (1). It interacts with GABAA receptor and also shows some pharmacological properties of benzodiazepines (2). It also possesses potent anticonvulsant activity against pentylenetetrazole- and electroshock-induced convulsions (3) and is rapidly and completely absorbed after oral administration. However, it undergoes extensive first pass hepatic metabolism after absorption, with only 30% of zaleplon being systemically available (4). Zaleplon attains peak concentration (Cmax) within 1.1 h (tmax) approximately after administration, with terminal elimination half life of 1 hour (5). Cmax and area under the plasma concentration–time curve (AUC) both exhibit linear dose proportionality at doses up to 60 mg well above the 10 mg therapeutic dose (6,7). Fig. 1 Chemical structure of zaleplon Although zaleplon is rapidly absorbed after oral administration, its poor aqueous solubility (8) (practically insoluble) can make its absorption dissolution rate limited and thus delay onset of action. The dissolution of drugs is a prime determinant in the absorption of poorly water-soluble drugs and also serves as a rate-limiting step (9). No information is available on the improvement of these drug-like properties of zaleplon. In this article increasing the solubility of zaleplon has been addressed via solid dispersion technique. The formulation of poorly water-soluble drugs is one of the most challenging tasks to the formulation experts. An enhancement in the solubility and the dissolution rate can improve the oral bioavailability of such drugs, which further improves the therapeutic efficacy and patient compliance. Various techniques have been used to enhance the solubility of poorly water-soluble drugs, including the use of surfactants (10), inclusion complexation (11), use of polymorph (12), and amorphous form of drug micronisation (13) and solid dispersion (14–16). The solubilization of drug from solid dispersion systems is mainly because of the reduction in particle size, increase in the surface area and reduction in the crystallinity that improves dissolution rate. Also, no energy is required to break up the crystal lattice of a drug during dissolution process and drug solubility and wettability may be increased by surrounding hydrophilic carriers (17). The various methods used to prepare solid dispersions are the hot melt method (18,19), solvent evaporation (20), spray drying (21), hot melt extrusion (22), solvent deposition technique (23) and solvent wetting method (24). The aim of the present study was to enhance the dissolution rate of zaleplon using solid dispersion technique with various hydrophilic polymers. The solvent evaporation method was used to prepare solid dispersion particles of zaleplon. Solid dispersion systems and physical mixtures of zaleplon were prepared with poloxamer F68, polyvinylpyrrolidone K30 (PVP K30), and polyethyleneglycol 6000 (PEG 6000) each in 1:1, 1:3 and 1:5 ratios. The selection of different ratios of polymers was purely on random basis. The solid-state properties of these binary systems were studied by thin layer chromatography, Fourier transformation infrared spectroscopy, X-ray powder diffractometry and differential scanning calorimetry. The dissolution behavior of zaleplon and its binary systems were further evaluated.