Synthesis of polythiophene n-type and p-type doping and compensation

The synthesis of pdythiophene leading to the formation of n-type potythiophene, p-type polythiophene and neutral polythiophene has been investigated through electropolymerization with different dopant ions. The influence of doping level over conductivity of the polymer matrix has also been studied which reveals that a preselected room temperature conductivity can easily be imparted to the parent polymer chain. It has also been found that the compensation of one type of conductivity over other occurs during the process of dedoping and redopin

Mathematical Modelling of Indian Regional Navigation Satellite System Receiver

At present the armoured fighting vehicles are equipped with either global positioning system (GPS) receivers or integrated inertial navigation system (INS)/GPS navigation systems. During hostile situations, the denial/degradation of the GPS satellite signals may happen. This results in the requirement of an indigenous satellite based navigation system. Indian Space Research Organisation has developed an indigenous Indian regional navigation satellite system (IRNSS), with a seven satellite constellation to provide independent position, navigation and timing services over India and its neighbouring regions. In this paper, the development of IRNSS receiver using MATLAB as per IRNSS signal in space interface control document for standard positioning service is discussed. A method for faster IRNSS signal acquisition in frequency domain and delay locked loop code tracking for the acquired satellite signals are used. Models for navigation message decoding and pseudo range/user position calculations are developed using the algorithms provided in IRNSS ICD

Formulation and evaluation of osmotic drug delivery system of ibuprofen

The authors are thankful to Mr.S.Sriram Ashok B.E, Correspondent, Sankaralingam Bhuvaneswari College of Pharmacy, Anaikuttam, Sivakasi, for providing necessary facilities to carry out the work.Aim: The present work was aimed to formulate and evaluate osmotic pump delivery system of Ibuprofen to provide a uniform concentration of drug at the absorption site and thereby maintain the plasma concentration within therapeutic range, which minimizes side effects and reduces the frequency of administration. Material and Methods: In the present work, 5 formulations (F1 to F5)of Ibuprofen osmotic drug delivery systems(ODDS) were prepared using two osmogens (NaCl and KCL) in two concentrations and a control F6 (without osmogens) by wet granulation technique. The excipients used in this study did not alter physicochemical properties of the drug, as tested by FTIR. Prior to compression, the prepared granules were evaluated for flow and compression characteristics. After compression, the tablets were evaluated for hardness, thickness, weight variation, friability, percentage of weight gain, drug content, in vitro release and stability studies. Results: The results revealed that the pre-compression and post-compression parameters are within the limits. Among all the formulations, F3 showed a controlled drug release of 63.54% at the end of 10th hour. The results of optimized formulation (F3) subjected to stability studies for 60 days at 27º±2ºC/60 ± 5% RH and 50º±2ºC/75 ± 5% RH showed that there was no significant change in the drug content and percentage drug release and the product was stable even after 2 months. Conclusions: From the study, it was concluded that Ibuprofen osmotic pump tablet prepared with potassium chloride (10%) as osmogent and cellulose acetate as coating polymer may be considered as a suitable alternative to currently available formulations of Ibuprofen.Objetivos: El objetivo del presente trabajo ha sido formular y evaluar el sistema de suministro de ibuprofeno mediante bomba osmótica para proporcionar una concentración uniforme de fármaco en el sitio de absorción y por lo tanto mantener la concentración plasmática dentro del intervalo terapéutico, lo que minimiza los efectos secundarios y reduce la frecuencia de administración. Material y Métodos: En el presente trabajo, 5 formulaciones (F1 a F5) de sistemas de administración de ibuprofeno osmótico (odds) se prepararon utilizando dos osmoagentes (NaCl y KCl) en dos concentraciones y un control (F6) (sin osmoagentes) por la técnica de granulación en húmedo. Los excipientes utilizados en este estudio no alteran las propiedades fisicoquímicas del fármaco, según lo testado por FTIR. Antes de la compresión, los gránulos preparados se evaluaron para la fluidez y la compresión. Después de la compresión, los comprimidos se evaluaron para la dureza, espesor, variación de peso, la friabilidad, el porcentaje de ganancia de peso, contenido de fármaco, la liberación in vitro y estudios de estabilidad. Resultados: Los resultados revelaron que los parámetros pre y post-compresión están dentro de los límites. Entre todas las formulaciones, F3 mostró una liberación controlada de fármacos de 63,54% al final de la décima hora. Los resultados de formulación optimizada (F3) sometido a estudios de estabilidad durante 60 días a 27º ± 2 °C/60 ± 5% HR y 50±2 °C/75 ± 5% HR mostraron que no hubo ningún cambio significativo en el contenido de fármaco y el porcentaje de liberación del fármaco y el producto fue estable incluso después de 2 meses. Conclusiones: En el estudio, se llegó a la conclusión de que la tableta de bomba osmótica ibuprofeno preparado con cloruro de potasio (10%) como osmoagente y acetato de celulosa como el polímero de revestimiento puede ser considerado como una alternativa adecuada actualmente disponibles para la formulaciones de ibuprofeno.Fund granted by College management and the research work was approved for the award of Degree of Master of pharmacy by The Tamilnadu Dr.MGR Medical University, Chennai, Indi

Studies on the blends of n-butylme thacrylate ethyl acrylate copolymers chlorinated rubber as top coat

The copolymers of n-butylmethacrylate-ethylacrylate were blended with chlorinated rubber in solution. The lacquers were formulated based on each blends and their utility as top coats on leather substrates were assessed. It was concluded that the blends resulted out of the above two polymer systems serve as the source for the formulation of top coats on leather substrate

Montmorillonite-catalysed regiospecific rearrangement of benzyl phenyl ether

301-30

Clay catalysed facile rearrangement of diazoaminobenzene to p-aminoazobenzene

187-18

2-(4-Chloro­phen­yl)-1,5-diphenyl-3-tosyl­imidazolidin-4-one

In the title compound, C28H23ClN2O3S, the central imidazolidine ring adopts a twisted conformation and the S atom has distorted tetra­hedral geometry. The crystal packing is stabilized by C—H⋯O, C—H⋯π and π–π inter­actions [centroid–centroid distance = 3.8302 (10) Å]

3-Ethyl-5-(4-meth­oxy­phen­oxy)-2-(pyridin-4-yl)-3H-imidazo[4,5-b]pyridine

In the title compound, C20H18N4O2, the imidazopyridine fused ring system is almost perpendicular to the benzene ring [dihedral angle = 87.6 (5)°]. The pyridine ring makes a dihedral angle of 35.5 (5)° with the mean plane of the imidazopyridine fragment. The crystal structure is stabilized by an aromatic π–π stacking inter­action between the phenyl rings of neighbouring mol­ecules [centroid–centroid distance = 3.772 (2) Å, inter­planar distance = 3.546 (2) Å and slippage = 1.286 (2) Å]

Ibuprofen-loaded calcium phosphate granules : combination of innovative characterization methods to relate mechanical strength to drug location

This paper studies the impact of the location of a drug substance on the physicochemical and mechanical properties of two types of calcium phosphate granules loaded with seven different contents of ibuprofen, ranging from 1.75% to 46%. These implantable agglomerates were produced by either low or high shear granulation. Unloaded Mi-Pro pellets presented higher sphericity and mechanical properties, but were slightly less porous than Kenwood granules (57.7% vs 61.2%). Nevertheless, the whole expected quantity of ibuprofen could be integrated into both types of granules. A combination of surface analysis, using near-infrared (NIR) spectroscopy coupling chemical imaging, and pellet porosity, by mercury intrusion measurements, allowed ibuprofen to be located. It was shown that, from 0% to 22% drug content, ibuprofen deposited simultaneously on the granule surface, as evidenced by the increase in surface NIR signal, and inside the pores, as highlighted by the decrease in pore volume. From 22%, porosity was almost filled, and additional drug substance coated the granule surfaces, leading to a large increase in the surface NIR signal. This coating was more regular for Mi-Pro pellets owing to their higher sphericity and greater surface deposition of drug substance. Unit crush tests using a microindenter revealed that ibuprofen loading enhanced the mechanical strength of granules, especially above 22% drug content, which was favorable to further application of the granules as a bone defect filler