No abstract

No abstract

No abstract

A sensitive, selective rapid bioanalytical assay method was developed and quantification of iloperidone (ILP) and olanzapine (OLZ) in rat plasma was done by mass spectrometry. Systematic sample preparation and extraction procedure were carried out by supported liquid extraction using dichloromethane to extract both the eluents (ILP and OLZ) from rat plasma samples. The extorted samples were injected on a selective Waters XTerra® C18 reverse-phase bonded column (250 × 4.6 mm i.d., 5 μm) using acetonitrile and 15 mM ammonium formate containing 0.05% trifluoroacetic acid (60:40 v/v) for isocratic elution mode and detected by mass spectrometry. Calibration curves were drawn with the respective assay statistical data and showed linear regression coefficients greater than 0.9996 over the concentration ranges 2-5,000 ng/mL for ILP and OLZ, respectively. The absolute mean recoveries were found to be in the replicate range of 87.12-94.47%, respectively. The obtained results by the method revealed good intra and interday assay performance in terms of 1.70-5.90% precision and 0-5% accuracy. The validated bioassay method has been successfully applied to the pharmacokinetics in rats.

Background: A new stability indicating RP-HPLC based assay method was developed to quantify ivermectin and praziquantel simultaneously and applied effectively to tablets. Methods: The simultaneous assay of ivermectin and praziquantel by RP-HPLC was done using an YMC C18 (250 mm × 4.6 mm, 5 µm) column with a mobile phase mixture of 0.1M disodium hydrogen phosphate (pH 4.5) and acetonitrile (55:45, v/v) using a isocratic flow rate of 1.0 ml/min and measured at 242 nm using photodiode array detector. All parameters were validated following the ICH guiding principles. The method was applied to quantify ivermectin and praziquantel simultaneously in tablets. Results: The retention values of ivermectin and praziquantel were 3.465 min and 4.468 min, respectively. The method’s linearity was found to be 1-3 µg/ml (ivermectin) and 25-75 µg/ml (praziquantel). The limit of detection was 0.010 µg/ml (ivermectin) and 0.046 µg/ml (praziquantel); limit of quantification was 0.033 µg/ml (ivermectin) and 0.155 µg/ml (praziquantel). The percent relative standard deviation of ivermectin and praziquantel was ˂1.0%. The percent assay was 99.51% and 99.20% for ivermectin and praziquantel, respectively. In tablets, the percent recovery of ivermectin and praziquantel was 99.60% and 99.38% with a percent relative standard deviation value of 0.353% and 0.106%, respectively. Stability indicating capability of the method was demonstrated through the stress degradation studies. Conclusion: The developed method was proved to be selective, precise and accurate for the quality control of ivermectin and praziquantel in tablets.

No abstract

Dehydrogenation of methanol on copper catalysts supported on SiO, and modified by Cr,03 was studied in the temperature range of 200 to 270°C. The chief product of reaction was methyl formate together with carbon monoxide and traces of formaldehyde.It was found that very high and sustained activity could be achieved by the method adopted for preparation of the catalysts. The unused catalyst was completely amorphous, but in catalyst samples used for Eng periods of time the presence of crystallites in the size runge 50 to 65 A was observed.Nearly 80 % of theoretically obtainable conversion of methanol to methyl formate was achieved in laboratory scale tubular reactor. A catalyst containing Cu: Cr,03:Si0, = 54:5.90: 7.0 prepared by the method described proved to be very active at low temperatures, giving 41 % conversion to methyl formate at 230°C for long periods of use. N o interaction between the active component and the support was noticeable.Addition of chromia improved the catalyst texture and stability. When nickel was present in quantities less than 1.25 %, it acted as a promoter and gave improved performance.

No abstract