DEVELOPMENT AND EVALUATION OF DROTOVERINE TASTE MASKED TABLETS WITH IMPROVED DISSOLUTION EFFICIENCY USING SOLID DISPERSION TECHNIQUE
The purpose of this research is to mask the bitter taste of the drug, Drotoverine using solid dispersion technique. The taste-masked drug is formulated in to a conventional tablet by direct compression method for ease of administration. Taste masking was done by solid dispersion using polymer such as urea and mannitol by melting/fusion method Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were performed to identify the physicochemical interaction between drug and carrier, hence its effect on dissolution. Conventional taste masked tablets were evaluated for weight variation, disintegration time, hardness and friability. In vitro drug release studies were performed for conventional tablets of drotoverine. Bitterness score was evaluated on volunteers. FTIR spectroscopy and SEM showed no interaction between drug and carriers. Conventional tablets prepared using solid dispersion, showed faster disintegration and complete bitter taste masking of drotoverine. In addition the prepared tablets exhibited better dissolution profile. Taste evaluation of taste masked tablets in human volunteers rated tasteless with a score of 0. Thus, results conclusively demonstrated successful masking of taste and oral disintegration of the formulated tablets in the oral cavity with improved dissolution.
Formulation and In-vitro Evaluation of Immediate release tablets of Drotaverine HCl
The aim of the present study is to develop and evaluate the immediate release tablet of Drotaverine HCL. Wet granulation method was used because of very high flow of powder blend that might create the problem of uneven dye filling. The Superdisintegrant AC-Di-Sol and Crospovidone were used for immediate release of drug from tablet. The coating was done to minimize the oxidation of Drotaverine HCL. From the results, it can be concluded that increase in concentration of superdisintegrant will lead to decrease the disintegration time up to 8 min after coating without any change observed in the dissolution profile of drug.
Neutron Residual Stress Measurements on Rail Sections for Different Production Conditions
Rail sectioning with subsequent neutron diffraction experiments has been used to assess residual stresses in the rails. In this study we present the results of neutron stress measurements performed at the NIST Center for Neutron Research (NCNR) on rail sections from rails that were produced under various conditions. Specifically, these are air-cooled, air-cooled and roller-straightened, head-hardened and head-hardened and roller-straightened. More significantly, a head-hardened and roller-straightened rail was also studied after service to elucidate evolution of the service-induced residual stresses. In the latter case both a transverse-cut slice and the central region of a 0.53 m long piece were studied. Measurements on this piece are the first in which triaxial stresses have been determined for an intact rail. Neutron strain measurements with 3×3×3 mm3 spatial resolution were successfully employed for transversally cut slices to verify the difference in the stress state depending on the production process. Although examination of slices allows determination of only two-dimensional stresses in the plane of the slice, additional measurements on obliquely-cut slices, which were also carried out, and utilization of FEM gives the possibility of reconstructing the full triaxial stress distribution. Together, these approaches provide a better understanding of rail fabrication and the possibility of improving the durability and safety of rails in the future.Copyright © 2004 by ASME