RESUMO
A high-pressure liquid chromatographic method was developed for the quantitative determination of polythiazide in pharmaceutical tablet formulations after extraction of the powdered tablets with a water-acetonitrile solvent. Analysis is a accomplished by comparison of peak areas after chromatography.
Assuntos
Politiazida/análise , Cromatografia Líquida de Alta Pressão , Métodos , ComprimidosRESUMO
A method was developed for the quantitative determination of thiothixene in pharmaceutical formulations by high-pressure liquid chromatography after dissolution of the sample in methanol.
Assuntos
Tiotixeno/análise , Cápsulas/análise , Cromatografia Líquida de Alta Pressão , Cromatografia em Papel , Soluções/análiseRESUMO
The physiochemical properties, amino acid composition and profile of the the tryptic peptides for an alkaline subtilopeptidase type Pfizer have been determined. The enzyme is stable in the pH range from 5 to 10, has a pH optimum of 9.5 to 10, and is relatively stable for a period of 2 h up to a temperature of 50C. Homogeneity was demonstrated by electrophoretic techniques and the mobilities indicated on isoelectric point of 8.7. The molecular weight was found to be 25,000 by gel filtration. The amino acid composition was found to be Ala32, Arg4, Aspgamma8, Glu15, Gly29, His4, Ile9, Leu13, Lys11, Met5, Phe4, Pro14, Ser31, Thr17, Tyr9, Val22, a total of 247 amino acid residues. The enzyme does not contain either disulfide bonds or cysteine, and lacks tryptophan as well. The N-terminal end-group residue is alanine: the C-terminal amino acid is arginine. Tryptic hydrolysis of the enzyme produced 15 peptides which were separated by gradient elution on Dowex 50-X2. The amino acid composition of each appropriately purified tryptic peptide was established.
Assuntos
Endopeptidases/análise , Aminoácidos/análise , Bacillus subtilis/enzimologia , Eletroforese em Gel de Poliacrilamida , Endopeptidases/metabolismo , Temperatura Alta , Concentração de Íons de Hidrogênio , Peso Molecular , Fatores de Tempo , Tripsina/farmacologiaRESUMO
In the microbiological assay for the determination of trace amounts of penicillin, it has been shown that sodium citrate and penicillin act synergistically against Sarcina lutea. The inhibitory action of citrate appears to involve a sequestering of divalent cations essential to the growth of the organism as shown by minimal inhibitory concentration and agar diffusion studies. The addition of calcium or magnesium to broth or agar at various concentrations overcomes this inhibition, and 0.02 M magnesium was found to be the most effective concentration. On agar supplemented with magnesium chloride, penicillin dose-response curves with and without citrate present were practically superimposable, and larger inhibition zones against a greater amount to total growth resulted in improved assay susceptibility and an interference-free method. Misleading results can be obtained when pharmaceutical products containing citrates are tested by conventional methods for penicillin cross-contamination.
Assuntos
Citratos , Penicilinas/análise , Bioensaio , Cálcio/farmacologia , Meios de Cultura , Magnésio/farmacologia , Penicilinas/farmacologia , Sarcina/efeitos dos fármacosRESUMO
A method was developed for the quantitative determination of chlorpropamide in tablet formulations by high-pressure liquid chromatography after homogenization of the sample with methanol.
