71 research outputs found
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
Screening of Syzygium cumini (L.) Seed Ethanol and Hexane Extracts for Phytochemicals, Antioxidant, and Anti-Diabetic Efficacy: An In-vitro Study
Many medicinal plant extracts have been known since ancient times to possess antioxidant activity to scavenge free radicals and anti-diabetic activity to control diabetes. In this study, seeds of Syzygium cumini were extracted in ethanol and hexane solvents. Primary and secondary metabolites were quantified. DPPH assay, nitric oxide scavenging (NOS) assay and ferric reducing antioxidant power (FRAP) assays were employed to study antioxidant activity. α-amylase inhibitory assay (AAI), yeast glucose uptake assay (YGU) and haemoglobin glycosylation inhibitory (HGI) assays were adapted to determine anti-diabetic properties. The results from the assays and the IC50 values (18.35 µg/ml in DPPH, 943.8 µg/ml in NOS, 871.3 µg/ml in FRAP, 886 µg/ml in AAI, 764 µg/ml in YGU, and 1495.1 µg/ml in HGI assay) indicate that S. cumini seed ethanol extract has higher antioxidant and anti-diabetic efficiency than the hexane extract. Our findings suggest that the rich phytochemical content of S. cumini seeds and its good antioxidant and anti-diabetic activity may be responsible for its popularity and wide traditional use and can be exploited to develop antioxidant and anti-diabetic drugs
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
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