Colorimetric method for determination of corticosteroids by UV Visible Spectroscopy and its application to Ayurvedic formulations

Usage of herbomineral preparations increased drastically these days. Some of the Ayurvedic formulations are been adulterated with steroids. Usage of such formulations can be injurious to health. Hence an attempt has been made to identify and determine steroids in both Ayurvedic and pharmaceutical formulations. In the present study a simple, sensitive and economical visible spectroscopic method has been used which involves the oxidation of corticosteroids by iron(III) and subsequent complexation of iron(II) with potassium  hexacyanoferrate (III), forming bluish green colored complex having the maximum absorbance at 780 nm. The method has been applied for the determination of corticosteroids in Ayurvedic formulations. The method has been statistically validated in which the  Standard deviation ranging  from  0.0008 to 0.0135,Relative standard deviation from 0.08% to 1.35% and Standard error was varying from 0.0018 to 0.0060 for selected Ayurvedic formulations. The studies have shown that the method is fast, reproducible and accurate and can be used in the analysis of marketed formulations. The processed samples were stable up to 2 hours minimizing the error in terms of fluctuating absorbance values

A Preliminary Study on Bladder-Assisted Rotomolding of Thermoplastic Polymer Composites

In this preliminary work, a new process is examined for manufacturing hollow parts from continuous fiber-reinforced thermoplastic polymer. The new process combines the basic idea of bag forming (or bladder-assisted forming) with the rotation of the mold for the processing of thermoplastic matrix composites. A pressurized membrane is used to compact the composite on the inner wall of a mold, which is placed inside a forced convection oven. The mold is removed from the oven for the cooling stage. The process was initially developed by using a thermoplastic pre-preg obtained using yarns of commingled E-glass fibers with isotactic polypropylene (iPP). A preliminary characterization of the thermoplastic composite showed that the material can be consolidated with pressures as low as 0.01 MPa, which is readily achievable with the process of this study. The design of the mold and membrane was carried out on the basis of both structural analysis of the aluminum shell and thermal analysis of the mold. The mold thickness is of great importance with respect to both the maximum pressure allowed in the process and the overall cycle time. Molding was performed on stacks of three and six layers of yarn, varying the applied pressure between 0.01 and 0.05 MPa and maximum temperature of the internal air between 185◦C and 215◦C. The composite shells obtained under different processing conditions were characterized in terms of physical and mechanical properties. Mechanical properties comparable with those obtained by compression molding and vacuum bagging were obtained. The maximum values obtained are 12.1 GPa and 290 MPa for the flexural modulus and the flexural strength, respectively. Furthermore, the results obtained show that mechanical properties improve with increasing the pressure during the cycle and with the maximum temperature used in the process