ABSTRACT
BACKGROUND & OBJECTIVES: Cetrimide is a monocationic surfactant, commonly used for disinfection of hospital floors, equipments, for cleansing of burns and wounds, hand wash, etc. We evaluated whether antibiotic resistant (AR) Escherichia coli isolates from hospital settings (nosocomial pathogens) show any evidence of significant reduction in their susceptibility to cetrimide. Also the response of AR E. coli (nosocomial pathogens) to the action of cetrimide was assessed by studying the ultra structural changes induced using transmission electron microscopy (TEM). METHODS: A total of 165 clinical samples were screened for isolation of E. coli. Eighty two (49.6%) samples were positive for E. coli. Antibiotic susceptibility testing of E. coli isolates was carried out by Kirby Bauer method to isolate AR E. coli. The randomly selected AR E. coli isolate was treated with different concentrations of cetrimide and minimum inhibitory concentration (MIC) of cetrimide was determined by broth micro dilution method. This same isolate was used for performing time kill assay and TEM study. RESULTS: The test E. coli isolate showed resistance to 12 different antibiotics. The MIC of cetrimide against AR E. coli was 312.5 microg/ml. The ultra cellular structural changes in cetrimide treated AR E. coli revealed vacuole formation, disaxilization of nuclear material, loss of cytoplasmic granularity, bleb formation and cell lysis. CONCLUSION: Ultra structural changes induced by the action of cetrimide revealed cell damaging changes in the AR E. coli to be dose and time dependent. The results showed that antibiotic resistance does not alter any change in susceptibility of E. coli to cetrimide, which was found to be still an effective disinfectant against a nosocomial pathogen E. coli.
Subject(s)
Anti-Infective Agents, Local , Cations/chemistry , Cetrimonium Compounds , Drug Resistance, Microbial/physiology , Escherichia coli , Surface-Active Agents , Animals , Anti-Infective Agents, Local/chemistry , Anti-Infective Agents, Local/pharmacology , Cetrimonium , Cetrimonium Compounds/chemistry , Cetrimonium Compounds/pharmacology , Escherichia coli/drug effects , Escherichia coli/physiology , Escherichia coli/ultrastructure , Humans , Microbial Sensitivity Tests , Surface-Active Agents/chemistry , Surface-Active Agents/pharmacologyABSTRACT
A simple, rapid, and precise reversed-phase liquid chromatographic method is developed for the simultaneous determination of metformin in combination with rosiglitazone. This method uses a Zorbax XDB C(18) 15-cm analytical column, a mobile phase of acetonitrile and buffer containing 10mM disodium hydrogen phsosphate, and 5mM sodium dodecyl sulphate in the ratio of 34:66 (v/v), and pH is adjusted to 7.1 with orthophosphoric acid. The instrumental settings are a flow rate of 1 mL/min, column temperature at 40 degrees C, and detector wavelength of 226 nm. The internal standard method is used for the quantitation of metformin and rosiglitazone. Methylparaben is used as an internal standard. The method is validated and shown to be linear. The correlation coefficients for metformin and rosiglitazone are 0.9996 and 0.9997, respectively. The relative standard deviation for six replicate measurements in two sets of each drug in the tablets is always less than 2%.
Subject(s)
Chromatography, High Pressure Liquid/methods , Metformin/analysis , Thiazolidinediones/analysis , Reference Standards , Reproducibility of Results , Rosiglitazone , Sensitivity and Specificity , Spectrophotometry, UltravioletABSTRACT
A simple, rapid, and precise method is developed for the quantitative simultaneous determination of metformin and pioglitazone in a combined pharmaceutical-dosage form. Separation is achieved with a Zorbax XDB C(18), 15-cm analytical column using buffer-acetonitrile (66:34, v/v) of pH 7.1, adjusted with orthophosphoric acid as the mobile phase. The buffer used in the mobile phase contains 10mM disodium hydrogen phosphate and 5mM sodium dodecyl sulphate in double-distilled water. The instrumental settings are flow rate of 1 mL/min, column temperature at 40 degrees C, and detector wavelength of 226 nm. The internal standard method is used for the quantitation of the ingredients of this combination. Methylparaben is used as an internal standard. The method is validated and shown to be linear for metformin and pioglitazone. The correlation coefficients for metformin and pioglitazone are 0.9991 and 0.9999, respectively. The relative standard deviations for six replicate measurements in two sets of each drug in the tablets are always less than 2%.
Subject(s)
Chromatography, High Pressure Liquid/methods , Dosage Forms , Hypoglycemic Agents/analysis , Metformin/analysis , Pharmaceutical Preparations/chemistry , Thiazolidinediones/analysis , Pioglitazone , Reproducibility of Results , Sensitivity and Specificity , Spectrophotometry, UltravioletABSTRACT
A robust, accurate and sensitive high-performance liquid chromatographic method for the determination of rosiglitazone (I) in human plasma has been developed. Pioglitazone (II) was used as internal standard. Both I and II are extracted from plasma using a liquid-liquid extraction procedure. Isocratic separation of I and II is carried out using a reversed-phase Zorbax SB C(18), 15-cm column with mobile phase consisting of methanol and a mixed phosphate buffer (10 mM monobasic sodium phosphate and dibasic sodium phosphate, pH adjusted to 2.6 with ortho-phosphoric acid) in the ratio 30:70 (v/v) and quantified by UV detection at 245 nm. Linearity was established over the range 5-1250 ng/ml using 1 ml human plasma. The method is specific, the endogenous components in plasma do not interfere with I and II. C.V. (%) of intra-day samples is less than 5.0% at four concentrations tested namely 5, 10, 500 and 1000 ng/ml. Similarly, over the same nominal concentrations, the precision of inter-day (5 days) samples also results in C.V. (%) less than 5.0%. The recoveries of I and II from human plasma were about 79 and 60%, respectively. This method can be used for routine clinical monitoring of I.
