Extractive Spectrophotometric Determination of Omeprazole in Pharmaceutical Preparations

Purpose: To develop a simple, rapid and selective method for the extractive spectrophotometric determination of omeprazole using acidic dyes. Methods: Extractive spectrophotometric determination of omeprazole was developed using acidic dyes - bromophenol blue and orange G - as ion-pairing agents in aqueous medium (pH 7.0 and 6.0, respectively). The ion pair chromogen formed, which was extracted with chloroform, was measured quantitatively at 408 nm and 508 nm, respectively. The developed method was used to analyse commercial omeprazole tablets.Results: Using bromophenol blue and orange G dyes, the ion-paired formed obeyed Beer’s law in the ranges 5 - 30 μg/ml and 50 - 250 μg/ml at 408nm and 503nm, respectively, with molar absorptivities of1.712 × 103 L mol-1 cm-1 and 2.095 × 103 L mol-1 cm-1, respectively, for omeprazole,. The purity of omeprazole obtained was 98.1±0.9 and 99.7±0.3, respectively. Standard deviation (S.D.), % relativestandard deviation (% R.S.D.) and standard error were 0.001 - 0.013, 0.94 - 1.07 % and 4 × 10-4, respectively. The complexes formed were stable for approx. 3 h. Conclusion: Recovery studies gave satisfactory results indicating that none of the major additives/excipients interferred with the assay method. Therefore, a simple, rapid and selective methodwas developed for extractive spectrophotometric determination of omeprazole. This method may be useful for routine laboratory analysis of omeprazole

Standard thermodynamic data for Rhodochrosite from equilibrium decomposition curve

Hydrothermal equilibrium decomposition curve for MnCO3 half arrow pointing right over half arrow pointing left MnO + CO2 in the total CO2 pressure range of 100-1700 bars and temperature range of 500-800-degrees-C was studied. The standard thermodynamic data obtained are: DELTA-H(f)0 = -894.382 +/- 0.74 kJ/mol and DELTA-G(f)0 = -822.170 +/- 0.74 kJ/mol. These values are more negative than the reported calorimetric data

Characterization of the gamma-aminobutyric acid signaling system in the zebrafish (danio rerio hamilton) central nervous system by reverse transcription-quantitative polymerase chain reaction

In the vertebrate brain, inhibition is largely mediated by raminobutyric acid (GABA). This neurotransmitter comprises a signaling machinery of GABA(A), GABA(B) receptors, transporters, glutamate decarboxylases (gads) and 4-aminobutyrate aminotransferase (abat), and associated proteins. Chloride is intimately related to GABAA receptor conductance, GABA uptake, and GADs activity. The response of target neurons to GABA stimuli is shaped by chloride-cation co-transporters (CCCs), which strictly control Cl- gradient across plasma membranes. This research profiled the expression of forty genes involved in GABA signaling in the zebrafish (Danio rerio) brain, grouped brain regions and retinas. Primer pairs were developed for reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The mRNA levels of the zebrafish GABA system share similarities with that of mammals, and confirm previous studies in non-mammalian species. Proposed GABAA receptors are alpha(1)beta(2)gamma(2), alpha(1)beta(2)delta, alpha(2b)beta(3), alpha(2b)beta(3)delta, alpha(4)beta(2)gamma(2), alpha(4)beta(2)gamma, alpha(6b)beta(2)gamma(2) and alpha(6b)beta(2)delta. Regional brain differences were documented. Retinal hetero- or homomeric rho-composed GABAA receptors could exist, accompanying alpha(1)beta(y)gamma(2), alpha(1)beta(y)delta, alpha(6a)beta(y)gamma(2,) alpha(6a)beta(y)delta. Expression patterns of alpha(6a) and alpha(6b) were opposite, with the former being more abundant in retinas, the latter in brains. Given the stoichiometry alpha(6w)beta(y)gamma(z), alpha(6a-) or alpha(6b)-containing receptors likely have different regulatory mechanisms. Different gene isoforms could originate after the rounds of genome duplication during teleost evolution. This research depicts that one isoform is generally more abundantly expressed than the other. Such observations also apply to GABAB receptors, GABA transporters, GABA-related enzymes, CCCs and GABAA receptor associated proteins, whose presence further strengthens the proof of a GABA system in zebrafish