Poisson Regression Modeling of Diarrhea Events in Pasuruan Regency with Maximum Likelihood Estimates and Generalized Method Moment.

CONTEXT: Diarrhea characterized by a frequency increased of defecation more than 3 times/ day accompanied by changes in consistency (becoming liquid). The causes of diarrhea can be divided into 2 parts, which are direct causes and indirect causes that can facilitate or accelerate the occurrence of diarrhea, including bacteria, nutritional conditions, hygiene and sanitation, social culture such as population density, economic status, low birth weight, and immunization. AIMS: The purpose of this study to examine the factors that influence the incidence of diarrhea. METHODS: This research used secondary data, the prevalence of diarrhea and risk factors in Pasuruan Regency Health Center. Poisson regression approach with maximum likelihood estimator (MLE) estimation and Generalized Method Moment (GMM) used in this study. RESULTS: The results showed that GMM estimation method in the Poisson regression model gave better performance in terms of significance parameters compared to the MLE method. CONCLUSIONS: Factors affecting the increase of diarrhea occurrences in area with an estimated MLE Percentage of non-exclusive breastfeeding and Percentage of normal nutritional status. Whereas the GMM estimation is the percentage of non-exclusive breastfeeding, the percentage of low birth weight, the percentage of population density, the percentage of smokers among family members in the house, the percentage of incomplete immunizations, the percentage of under-five years old children less than 2, the percentage of normal nutritional status, and the percentage of middle class socioeconomic status.

Post-column fluorescence derivatization of peptides. Problems and potential in high-performance liquid chromatography.

Some critical parameters such as the pumping system, mixing devices and detector design in instrumentation for post-column derivatization in high-performance liquid chromatography are discussed. The derivatization was studied with pharmaceutically important nona-peptides containing primary amino groups which react with Fluram and reaction parameters such as pH, solvent and reagent concentration were investigated. Both adsorption systems and reversed-phase systems were used to separate the peptides prior to the post-column reaction. Reversed-phase chromatography has the advantage of simpler sample preparation, better reaction control and optimization of solvent conditions. As a result, detection limits of between 5 and 10 ng per injection can be obtained and the reproducibility of the results is better than +/- 2% (relative standard deviation). The method has been applied to the analysis of injection solutions (ampoules).

Liquid chromatography of dansyl derivatives of some alkaloids and the application to the analysis of pharmaceuticals.

Derivatization of the alkaloids cephaeline, codeine, emetine, ephedrine, morphine, narcotine and others with dansyl chloride has been studied with the aim of developing a sensitive and specific liquid chromatographic method for these substances in complex pharmaceutical dosage forms. While codeine and narcotine do not react, the other compounds form completely substituted derivatives which possess maxima in their fluorescence emission spectra between 470 and 500 nm. The structure of the derivatives has been confirmed by nuclear magnetic resonance spectroscopy. The dansylated compounds have been separated by thin-layer chromatography and high-pressure liquid chromatography. The improved selectivity and sensitivity have permitted an analysis of these substances present in low concentrations in 10- 100-fold excesses of other drugs. Direct derivatization of syrups and aqueous slurries of capsules having a complex excipient and drug composition is feasible and time saving and serves as a pre-clean-up step. Detection limits are in the 1-10-ng range or better, depending on the efficiency of the detection device. The reproducibility of the method is limited by the derivatization step, but a relative standard deviation of less than 2% can be obtained. The analysis time for these pharmaceuticals may be reduced by at least one fifth of that required by conventional techniques.

High-speed ion-pair partition chromatography in pharmaceutical analysis.

Ion-pair chromatography offers attractive possibilities in pharmaceutical analysis. The specificity of the separation systems can be varied over a wide range by appropriate selection of the stationary phase. The choice of a suitable counter-ion can also drastically improve the detection limit, permitting the determination of drug substances in low dosage and possibly of by-products or breakdown products. Ion-pair chromatography of tropane and ergot alkaloids has been investigated using picrate as counter-ion. Alumina, Kieselguhr and various grades of silica gel have been tested as supports. Partition properties studied in a batch procedure have been compared with the actual chromatographic conditions. Columns (10 cm) filled with silical gel (particle size, 5 mum; pore size, 1000 A) show the best performance in the separation of hyoscyamine, scopolamine and ergotamine as picrate ion-pairs. Close control of pH and temperature is essential for reproducible separations. Improvements in detection limits between 100 and 300 times have been observed with these systems. Ion-pair extractions of these alkaloids from dosage forms can be used for sample preparation prior to injection on the the column. This provides an added degree of selectivity and sensitivity.

Combined ultraviolet-fluorescence detection in high-pressure liquid chromatography of pharmaceuticals.

The use of combined UV-fluorescence detection for the evaluation of incompletely resolved compounds and trace components in the presence of large quantities of major components is described, analysis for thioridazine and some of its oxidation products by high-pressure liquid chromatography being chosen as a practical example. Mesoridazine and the ring oxide of thioridazine have been determined quantitatively with relative standard deviations (n = 6) of 2.0 and 3.6%, respectively, at concentrations below 0.1 mug per injection. Resolution of the two components is difficult and, in this instance, unnecessary. By a similar approach, it was possible to determine the highly fluoresecent sulforidazine at a concentration of 0.4% of the thioridazine with 6.2 mug of thioridazine injected. A relative standard deviation of 5% was attainable at this concentration. Fluorescence detection limits for mesoridazine and sulforidazine at a signal-to-noise ratio of 4:1 are between 5 and 10 ng per injection; this corresponds to about 0.1% of the active substance for the above example.

The liquid chromatographic properties of phenothiazines.

The high-pressure liquid chromatographic behaviour of different groups of phenothiazines (drug substances) has been investigated on 10-mu m silica gel particles. Variation of the ammonia concentration between 0.5 and 1.5% in an isopropanol-diisopropyl ether (15:85) mixture permits the adjustment of the solvent system to fit the different basicities of the various groups of interest. While the capacity factors (k') for pairs of compounds in two homologous oxidation series vary considerably owing to differences in basicity, there is reasonably good agreement between the relative retention (alphs) values. This fact can be utilized in order to identify phenothiazine homologues of series that have not previously been studied. Elutropic diagrams in connection with alpha values can be used to predict the chromatographic behaviour of new groups of phenothiazines.