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Biomedical subjects

V P Pandey

Publications and source records attributed to V P Pandey.

7 recordsLinked to original sources
PubMed2006

Structural transition in nanostructured Eu2O3 under high pressures.

We report here studies on the effect of high pressure on the structural properties of nano-sized Europium sesquioxide (Eu2O3) up to a pressure of about 16.4 GPa. At ambient conditions, the starting sample was found to be predominantly cubic type Eu2O3 or in Eu3+ state with a trace of Eu2+. The presence of Eu2+ state is assumed to be arising due to the non-stoichiometric Eu(1-x)O phase which is obtained from XPS studies by the deconvolution of the Eu 3d-core levels. The Raman studies at ambient show a strong peak at about 333 cm(-1), which is known to occur due to the Fg mode of cubic Eu2O3 and in a similar way, the XRD data shows major peaks corresponding to the cubic phase of Eu2O3. A Mao-Bell type diamond anvil cell (DAC) was used to generate high pressures for XRD and Raman spectroscopy studies. It was observed that the material undergoes a structural change from cubic to monoclinic structure with an on set transition pressure at around 2 GPa and completes at around 8 GPa. This has been inferred from the fact that above about 2.0 GPa pressure, Raman studies show the emergence of a new peak corresponding to the monoclinic phase which increases in intensity and shifts further with increase in pressure, while the XRD studies show that above about 2.0 GPa, the peaks corresponding to monoclinic phase emerge, which show a slight increase in preferred orientation as the pressure is increased. A detailed discussion has been provided to explain this fact.

Europium↗
PubMed2003

In vitro study on sustained release capsule formulation of acetazolamide.

In the present study formulation of sustained release capsule of acetazolamide 250 mg was tried using nonpareil seeds. Nonpareil seeds were coated with drug, polyvinylpyrrolidone, glyceryl monostearate, microcrystalline wax, and glyceryl distearate either individually or in combination to achieve sustained release capsule 250 mg. In successful formulation 20% drug coated pellets and 80% wax coated pellets were taken. Wax coated pellets for successful formulation contained coating of microcrystalline wax and glyceryl distearate on drug coated pellets of the same concentration of 1.6% w/w. Successful formulated sustained release capsule 250 mg of acetazolamide was compared in in vitro study with theoretical sustained release formulation suggested by wagner and one marketed sustained release capsule 250 mg. Formulated capsule showed result superior to or on par with marketed capsule. For successful formulation pellets were filled in '1' size hard gelatin capsule and stability study was carried out in hot air over at room temperature and 45 degrees C for 5 weeks. The formulation was found stable in respect of drug content and release rate.

Acetazolamide↗
PubMed1989

Bronchoalveolar lavage study in victims of toxic gas leak at Bhopal.

Bronchoalveolar lavage using flexible fibreoptic bronchoscope was carried out in 50 patients 1-2 1/2 yr after exposure to the 'toxic gas' at Bhopal. Thirty six patients in the analysis were categorised into 3 groups (viz., mild, moderate and severe), depending upon the severity of exposure. There was an increase in cellularity in the lower respiratory tract (alveolitis) of the severely exposed patients (in both smokers and non-smokers), compared to normals (P less than 0.05). The increase in cellularity in severely exposed non-smokers was due to abnormal accumulation of macrophages (P less than 0.01), and in severely exposed smokers, to macrophages (P less than 0.01) and neutrophils (P less than 0.05). Mild and moderately exposed patients did not show significant change in cellularity in lower respiratory tract, compared to normal individuals (P greater than 0.2). There was a trend towards increasing cellularity, as the severity increased (P less than 0.0001) and higher numbers of total cells were seen in severely exposed smokers, suggesting that smoking is a risk factor. It appears, therefore, that subjects severely exposed to the toxic gas at Bhopal may have a subclinical alveolitis characterised by accumulation and possibly activation of macrophages in the lower respiratory tract. Smokers, who were exposed to the gas had in addition, accumulation of neutrophils.

Accidents, Occupational↗
PubMedDate not supplied

Sustaining pattern of phenformin hydrochloride using various polymers and waxes.

The present study was carried out to formulate matrix tablets of phenformin hydrochloride. Granules of phenformin HCl were prepared by using ethyl cellulose, eudragit RS 100, gum acacia, carnauba wax, stearyl alcohol, glyceryl monostearate and triethanol amine. Thus the granules were compressed and fourteen tablets formulations were prepared. All the physical parameters of granules and matrix tablets were studied including compatibility study. One commercial timed disintegration capsule was also included for study and comparison. The results of in vitro studies showed that sustained release matrix tablet might be prepared using carnauba wax, stearyl alcohol, triethanol amine and magnesium stearate.

Chemical Phenomena↗
PubMedDate not supplied

In vitro study on capsule formulations of omeprazole containing enteric coated granules.

Omeprazole is a unique and effective agent for suppression of gastric acid secretion. It promises to be especially useful in Zollinger-Ellison Syndrome (1) and in other patients who have failed to respond to H2 antagonist therapy. The dose requirement for zollinger-ellison syndrome (ZES) disease is upto 180 mg per day. The drug omeprazole shows biological half life of 2-3 hours. (2) Considering its proven therapeutic efficacy for ZES disease, this study is attempted to formulate sustained release capsule containing enteric coated granules. For formulating sustained release drug delivery system immediate release dose (IR) is calculated as 10 mg of drug and sustained release dose (SR) is taken as 50 mg. (3) The polymers used for retarding the release are Ethyl Cellulose (EC) and Hydroxy Propyl Methyl Cellulose (HPMC). Solvent evaporation technique is followed to prepare sustained release granules. Granules are finally coated with enteric coating of Suteric (Polyvinly acetate phthalate, PVAP). Thus the eight capsule formulations are prepared and formulation found very close to theoretical sustained release (TSR) according to in vitro study (4) is subjected to stability studies. Results show that product should be stored at room temperature or below ambient temperature.

Anti-Ulcer Agents↗