Influence of internal phase properties on zeta-potential and dielectric constant of o/w emulsion

Dielectric constant (DEC) of internal phase influenced the zeta potential (ZP) of o/w emulsion prepared with or without emulgent. In both systems ZP and DEC of internal phase exhibited an approximately linear relationship. Using homologous aliphatic hydrocarbons as internal phases, emulsions were prepared with polysorbate-80. Increase in carbon chain length brought about increase in interracial area and decrease in ZPs of emulsions. A fair inverse correlation between ZP and DEC of internal phase was revealed in this series. Increase in phase volume ratio from 0.05 to 0.3 brought about limited changes in ZPs whereas by further increasing phase volume ratio, ZP decreased steadily. Studies pertaining to the effect of phase volume ratio on DEC of o/w emulsions are in accordance with earlier observations. Increase in phase volume ratio causes a steady decrease in DEC of emulsion. Of the five equations employed, the Bruggeman equation appears to predict the observed values more accurately.     

Connection between Antarctic sea‐ice extent and Indian summer monsoon rainfall

Antarctic sea‐ice extent (AnSIE) is an important parameter influencing global climate. The present study is carried out to find whether any connection between the AnSIE and the Indian summer monsoon rainfall (ISMR) exists. Temporal cross‐correlations between the anomalies of the ISMR and AnSIE as a whole and its different sectors are computed for the period 1988 to 2005. A coherent propagating pattern is clearly evident between the AnSIE and ISMR, as well as the rainfall over most of the homogeneous geographical regions of India. Furthermore, this study reveals that the sea‐ice extent (SIE) of the western Pacific Ocean sector in the month of March has a strong association with that of the ISMR in the same year. Year 2002 was a major drought year, which none of the regional or general circulation models could simulate. AnSIE variation has provided a strong signal to imply that 2002 would be a deficit monsoon year.     

Pharmacokinetics of a single dose of phenylpropanolamine following oral administration at two different times of the day

Pharmacokinetics of a single oral dose of phenylpropanolamine (CAS 154-41-6) was investigated by administering 50 mg of the drug at 10.00 and 22.00 h to 8 healthy male volunteers in a crossover design with a wash-out period of 10 days. Serum samples were analysed for phenylpropanolamine using high performance liquid chromatography. Pharmacokinetic parameters were calculated using model independent method. A significant (p < 0.05) elevation in Cmax (227.45 versus 181.98 micrograms/l) was observed following the drug administration at 22.00 h as compared to 10.00 h. These variations may be due to circadian changes in gastric pH contributing to the time dependent changes in the absorption of the drug.     

Pharmaceutical Investigations of a Film Forming Material Isolated from Roots of Salacia Macrosperma

A film forming material (FFM) was isolated in pure form from chloroform extract of roots Salacia macrosperma (Hippocrataceae) and was found to be a polymer of isoprene. It was not absorbed through gastrointestinal tract of rats and non-toxic. Electronic microscopic studies on films prepared with different concentrations of FFM in various organic solvents revealed that chloroform is an ideal solvent for preparing uniform films. Use of FFM as a film coating material was evaluated