Evaluation of Residual Monomer Release After Polymerization of Colored Compomer Materials

ABSTRACT Objective: To evaluate the amount of residual monomers released after polymerization by the compomers in different colors and viscosities over time. Material and Methods: The compomer samples of different colors and viscosities (flowable compomers; blue-pink and packable compomers; A2-blue-pink-gold) were prepared in molds with an inner diameter of 5 mm and a height of 2 mm. In polymerization of samples, a LED unit was used. The amount of monomers released from the samples kept in 75% ethanol/water solution was measured by a high-performance liquid chromatography (HPLC) instrument in the 10th minute, in the 1st hour, and in the 1st, 7th, and 14th days. For statistical analyses, the paired sample t-test, independent sample t-test, and one-way ANOVA with Tukey's post hoc test were used. Results: The amount of residual monomers released from all materials increased over time. At the end of the 14th day, the most released monomer from all compomer samples was BisGMA. The total amounts of released monomers from the packable compomers were Gold>A2>blue>pink. The amount of residual monomers released from flowable compomers was higher in blue than in pink. Conclusion: The color and the viscosity are the factors affecting the residual monomer release in compomers.

Analytical lifecycle management oriented development and validation of a new stability-indicating ultra-fast liquid chromatographic method: case study of Glycopyrrolate

A new stability-indicating liquid chromatographic method was developed and validated for the estimation of glycopyrrolate in pharmaceutical formulations. A contemporary approach to analytical life-cycle management was followed to develop a robust and reliable chromatographic method. Scouted method variables such as % methanol, the strength of tetra butyl ammonium hydrogen sulfate and mobile phase flow rate were optimized using the design of experiment approach and their effect on critical quality attributes was studied. The critical quality attributes viz. retention time, theoretical plate count and symmetry factor were highly influenced by the three critical method variables. Optimum chromatography was attained on a C-18 column with a mobile phase methanol: 10 mM tetra butyl ammonium hydrogen sulfate (80:20, v/v) flowing at 1.0 mL.min-1. Chromatographic method specificity was ensured by degrading the drug forcefully. Validation studies postulated method acceptability and suitability for estimating glycopyrrolate in both bulk as well as injection formulation. Results for parameters viz. linearity (5-250 µg.mL-1), accuracy (>99%) and precision (<2%) advocated method reliability. Overall the method was reliable and of optimum quality and, possess the potential of application in routine and bio-analytical purposes

Characterization of Seed Oils of Pterodon emarginatus Vogel (Sucupira) Obtained by Different Extraction Methods

Abstract The present study aims to evaluate the influence of extraction methods on the quality of bioactive compounds and antioxidant capacity in Pterodon emarginatusVogel (sucupira) oils. The oils were extracted from the sucupira seeds by Soxhlet and by the extraction system of Bligh & Dyer. The oils were analyzed as to fatty acid profile, tocopherols, phytosterols, carotenoids, total phenolics, and total antioxidant capacity. The extraction by Soxhlet showed better yield of total lipids and was more efficient to extract tocopherols, phytosterols, and carotenoids, besides presenting better antioxidant activity by DPPH•. However, this method showed insufficient capacity to extract the polar lipid components of the sample, as evidenced by the low results of total phenolic compounds. On the other hand, the Bligh & Dyer method preserved the fatty acid profile and was also effective to extract higher phenolic compounds content and presented superior antioxidant activity when assessed by FRAP, ABTS•+, and oxidative stability index.

Imunochromatographic strip test detection of anti-rK39 antibody for the diagnosis of Kala-azar in an endemic zone of Bangladesh

A rapid immunochromatographic dipstick test [ICT] has become available for the qualitative detection of anti-Leishmania antibody using recombinant rK39 antigen. This study was carried out at the department of Microbiology of Rajshahi Medical College, Bangladesh, in order to evaluate the diagnostic potential of immunochromatographic dipstick test. A total of one hundred cases including 60 admitted patients with strong clinical suspicion of kata-azar and 40 healthy controls were investigated for the performance of the ICT Splenic smears were examined for microscopic detection of Leishman Donovan [LD] bodies obtained from the admitted patients only and smear-positive cases were considered as gold standard as well as confirmed cases of kala-azar. Out of 60 suspected patients, fifty three [88.33%] were found smear-positive and fifty nine [98.33%] were positive for immunochromatographic strip test. All smear-positive cases were also positive for strip test. Voluntary healthy controls [40], which included twenty persons from the endemic zone and twenty from non-endemic zone of kala-azar, were found all negative for the strip test. The sensitivity and specificity of immunochromatographic strip test were found to be 100.00% and 86.95% respectively. Present study findings again reinforce that the immunochromatographic strip test is a simple, reliable and easy-to-perform non-invasive diagnostic toot for visceral leishmaniasis in the endemic area of Bangladesh

An alternative column chromatographic process for the production of human albumin

We have modified a standard column chromatography method for the preparation of albumin from human plasma. The proposed method utilizes Sephadex G-25, euglobulin precipitation, DEAE-Sepharose, ethanol heat treatment and Sephacryl S-200 HR. The procedure differs from that normally used by the introduction of Schneider's ethanol/heat treatment step and the elimination of a CM-Sepharose step, after the DEAE-Sepharose step. The proposed method was used to produce 15 batches of albumin, 100 liters of plasma per batch. Purity of more than 99 percent was obtained at an average yield of 26.5 g/l plasma for the albumin produced. All batches presented 99.2 to 99.9 percent monomer and 0.1 to 0.8 percent dimer, with no larger polymers detected. The utilization of the final gel filtration step eliminated highly polymerized albumin usually obtained during the process. The advantages of the proposed method are reduction in the overall process time from 6 to 5 days, elimination of the CM-Sepharose step and the reduction of 6 to 4 columns in series for the Sephacryl S-200 HR step.

Biological markers in crude oils from Egypt

The main aim of this study was to investigate source -and maturity- dependent trends of a number of biomarker parameters in two Egyptian crude oil samples from Alamein and Badran oil-fields. The aliphatic and aromatic hydrocarbon fractions were examined by gas chromatography and combined gas chromatography-mass spectrometry. In all fractions, there is a high relative abundance of components of higher-plant origin. Molecular maturity measurements indicated that both oils are at an advanced level of thermal maturity and many ratios, such as CPI, C30 alpha beta/alpha beta + beta alpha hopanes, C31 22S/22S + 22R hopanes, C29 alpha alpha alpha-20S/20S + 20 R steranes, C29 alpha beta beta/ alpha beta beta + alpha alpha alpha steranes and methylphenanthrene index [MPI 1] have reached their thermal equilibrium values. Changes in the two trisnorhopane [Ts/Tm] ratio. However, showed a more advanced level of thermal maturity for Alamein oil and correlated well with trends of organic sulfur compound ratios and aromatic steroid cracking ratios

Studies on microbial lipids containing Alpha-linolenic acid

M. miehi was grown on a chemically defined medium with glucose as carbon source. Studies were made on the influence of pH, age of culture, sugar concentration and nitrogen concentration. The investigations were carried on the characteristics and detailed fatty acid composition. The cultural conditions were manipulated to get the maximum amount of lipids with a higher percentage of gamma-linolenic acid

Isolation of DNA methylase modification enzyme

Type II restriction endonuclease was isolated from locally isolated strain Enterobacter cloaca of recognition sequence CGATCG. Its cognate methylase was isolated and its 5 methyl Cytosine was confirmed by methylation and DNA hydrolysis

Isolation, separation and identification of food colours used in Sherbets

Two hundred samples of "Sherbets" [non-aerated drinks] were collected from private households, "Hakims" and shopkeepers/vendors. Food colours extracted were identified by subjecting them to thin layer chromatography along with the standards. About two third samples 62.5% were found to contain Amaranth a food colour whose listing was terminated by FDA in 1979. Twenty eight percent of the samples were found to contain not colours permitted by FDA as synthetic food colours