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1.
Fluorodensitometric evaluation of gentamicin from plasma and urine by high-performance thin-layer chromatography 总被引:1,自引:0,他引:1
Chhanda P Bhogte V.B Patravale Padma V Devarajan 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1997,694(2):1246
High-performance thin-layer chromatographic (HPTLC) analysis of gentamicin by in situ fluorodensitometric evaluation of its 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) derivative is presented. The aminoglycoside components separated on silica gel plates using chloroform–methanol–20% ammonium hydroxide (2.4:2.2:1.5, v/v/v) as the mobile phase were reacted with NB-Cl to yield highly fluorescent derivatives. The calibration curves of gentamicin in water, plasma and urine were linear in the range 40–200 ng. The mean values of intercept, slope and correlation coefficient were 16.82±0.473, 6.83±0.015 and 0.9968±0.0017 for standard curves in water, 17.35±0.375, 6.85±0.018 and 0.9941±0.0012 for standard curves in plasma and 14.35±0.286, 6.86±0.002 and 0.9933+0.0011 for standard curves in urine respectively. The analytical technique was validated for within-day and day-to-day variation. The results indicate that HPTLC, coupled with in situ fluorodensitometry, is a reliable and valuable technique for quantitative analysis of the bulk drug gentamicin and gentamicin from urine and plasma. 相似文献
2.
The aim of the present study was to investigate the potential of a phospholipid-based microemulsion formulation for parenteral
delivery of anticancer drug, etoposide. The microemulsion area was identified by constructing pseudoternary phase diagrams.
The prepared microemulsions were subjected to different thermodynamic stability tests. The microemulsion formulations that
passed thermodynamic stability tests were characterized for optical birefringence, droplet size, viscosity measurement, and
pH measurements. To assess the safety of the formulations for parenteral delivery, the formulation was subjected to compatibility
studies with various intravenous infusions and in vitro erythrocyte toxicity study. The developed formulation was found to be robust and safe for parenteral delivery. 相似文献
3.
Laercio R Porto-Neto Tad S Sonstegard George E Liu Derek M Bickhart Marcos VB Da Silva Marco A Machado Yuri T Utsunomiya Jose F Garcia Cedric Gondro Curtis P Van Tassell 《BMC genomics》2013,14(1)
Background
Natural selection has molded evolution across all taxa. At an arguable date of around 330,000 years ago there were already at least two different types of cattle that became ancestors of nearly all modern cattle, the Bos taurus taurus more adapted to temperate climates and the tropically adapted Bos taurus indicus. After domestication, human selection exponentially intensified these differences. To better understand the genetic differences between these subspecies and detect genomic regions potentially under divergent selection, animals from the International Bovine HapMap Experiment were genotyped for over 770,000 SNP across the genome and compared using smoothed FST. The taurine sample was represented by ten breeds and the contrasting zebu cohort by three breeds.Results
Each cattle group evidenced similar numbers of polymorphic markers well distributed across the genome. Principal components analyses and unsupervised clustering confirmed the well-characterized main division of domestic cattle. The top 1% smoothed FST, potentially associated to positive selection, contained 48 genomic regions across 17 chromosomes. Nearly half of the top FST signals (n = 22) were previously detected using a lower density SNP assay. Amongst the strongest signals were the BTA7:~50 Mb and BTA14:~25 Mb; both regions harboring candidate genes and different patterns of linkage disequilibrium that potentially represent intrinsic differences between cattle types. The bottom 1% of the smoothed FST values, potentially associated to balancing selection, included 24 regions across 13 chromosomes. These regions often overlap with copy number variants, including the highly variable region at BTA23:~24 Mb that harbors a large number of MHC genes. Under these regions, 318 unique Ensembl genes are annotated with a significant overrepresentation of immune related pathways.Conclusions
Genomic regions that are potentially linked to purifying or balancing selection processes in domestic cattle were identified. These regions are of particular interest to understand the natural and human selective pressures to which these subspecies were exposed to and how the genetic background of these populations evolved in response to environmental challenges and human manipulation.Electronic supplementary material
The online version of this article (doi:10.1186/1471-2164-14-876) contains supplementary material, which is available to authorized users. 相似文献4.
Ana M Pérez O’Brien Yuri T Utsunomiya Gábor Mészáros Derek M Bickhart George E Liu Curtis P Van Tassell Tad S Sonstegard Marcos VB Da Silva José Fernando Garcia Johann S?lkner 《遗传、选种与进化》2014,46(1):19
Background
Signatures of selection are regions in the genome that have been preferentially increased in frequency and fixed in a population because of their functional importance in specific processes. These regions can be detected because of their lower genetic variability and specific regional linkage disequilibrium (LD) patterns.Methods
By comparing the differences in regional LD variation between dairy and beef cattle types, and between indicine and taurine subspecies, we aim at finding signatures of selection for production and adaptation in cattle breeds. The VarLD method was applied to compare the LD variation in the autosomal genome between breeds, including Angus and Brown Swiss, representing taurine breeds, and Nelore and Gir, representing indicine breeds. Genomic regions containing the top 0.01 and 0.1 percentile of signals were characterized using the UMD3.1 Bos taurus genome assembly to identify genes in those regions and compared with previously reported selection signatures and regions with copy number variation.Results
For all comparisons, the top 0.01 and 0.1 percentile included 26 and 165 signals and 17 and 125 genes, respectively, including TECRL, BT.23182 or FPPS, CAST, MYOM1, UVRAG and DNAJA1.Conclusions
The VarLD method is a powerful tool to identify differences in linkage disequilibrium between cattle populations and putative signatures of selection with potential adaptive and productive importance. 相似文献5.
The objective of the present investigation was to develop and evaluate self-microemulsifying drug delivery system (SMEDDS)
for improving the delivery of a BCS class II antidiabetic agent, glyburide (GLY). The solubility of GLY in oils, cosurfactants,
and surfactants was evaluated to identify the components of the microemulsion. The ternary diagram was plotted to identify
the area of microemulsion existence. The in vitro dissolution profile of GLY SMEDDS was evaluated in comparison to the marketed GLY tablet and pure drug in pH 1.2 and pH 7.4
buffers. The chemical stability of GLY in SMEDDS was determined as per the International Conference on Harmonisation guidelines.
The area of microemulsion existence increased with the increase in the cosurfactant (Transcutol P) concentration. The GLY
microemulsion exhibited globule size of 133.5 nm and polydispersity index of 0.94. The stability studies indicated that GLY
undergoes significant degradation in the developed SMEDDS. This observation was totally unexpected and has been noticed for
the first time. Further investigations indicated that the rate of GLY degradation was highest in Transcutol P. 相似文献
6.
The objective of this investigation was to develop lorazepam (LZM) microemulsions as an alternative to the conventional cosolvent
based formulation. Solubility of LZM in various oils and Tween 80 was determined. The ternary diagram was plotted to identify
area of microemulsion existence and a suitable composition was identified to achieve desired LZM concentration. The LZM microemulsions
were evaluated for compatibility with parenteral fluids, globule size, in vitro hemolysis and stability of LZM. Capmul MCM demonstrated highest solubilizing potential for LZM and was used as an oily phase.
LZM microemulsions were compatible with parenteral dilution fluids and exhibited mean globule size less than 200 nm. The in vitro hemolysis studies indicated that microemulsions were well tolerated by erythrocytes. The LZM microemulsions containing amino
acids exhibited good physical and chemical stability when subjected to refrigeration for 6 months. 相似文献
7.
Dalapathi Gugulothu Sulabha Pathak Shital Suryavanshi Shobhona Sharma Vandana Patravale 《AAPS PharmSciTech》2010,11(3):1179-1184
Parasitic diseases are of immense global significance as around 30% of world’s population experiences parasitic infections.
Among these, malaria is the most life-threatening disease. Various routes of administration have been explored for delivering
antimalarial actives. The present investigation aims at formulating self-microemulsifying suppositories of β-artemether with
faster onset of action and prolonged effect to be administered by rectal route. These were compared with conventional polyethylene
glycol suppositories with respect to melting range, rheology, texture analysis, disintegration time, self microemulsification
time, particle size, and drug content. In vitro drug release was studied by using USP apparatus II. Further, the suppositories were evaluated in murine model against virulent
rodent malaria parasite Plasmodium berghei wherein the developed self-microemulsifying suppositories could sustain the activity (94%) for 20 days post infection. The
survival of animals was also better as compared to the conventional formulation. 相似文献
8.
In this article, we report the synthesis of Na2Sr1‐x(PO4)F:Eux phosphor via a combustion method. The influence of different annealing temperatures on the photoluminescence properties was investigated. The phosphor was excited at both 254 and 393 nm. Na2Sr1‐x(PO4)F:Eux3+ phosphors emit strong orange and red color at 593 and 612 nm, respectively, under both excitation wavelengths. Na2Sr1‐x(PO4)F:Eux3+ phosphors annealed at 1050°C showed stronger emission intensity compared with 600, 900 and 1200°C. Moreover, Na2Sr1‐x(PO4)F:Eux3+ phosphor was found to be more intense when compared with commercial Y2O3:Eu3+ phosphor. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
9.
The objective of the present investigation was to develop and evaluate microemulsion-based gel for the vaginal delivery of clotrimazole (CMZ). The solubility of CMZ in oils and surfactants was evaluated to identify components of the microemulsion. The ternary diagram was plotted to identify the area of microemulsion existence. Various gelling agents were evaluated for their potential to gel the CMZ microemulsion without affecting its structure. The bioadhesive potential and antifungal activity of the CMZ microemulsion-based gel (CMZ-MBG) was determined in comparison to the marketed clotrimazole gel (Candid-V® gel) by in vitro methods. The chemical stability of CMZ in CMZ-MBG was determined as per the International Conference on Harmonization guidelines. The CMZ microemulsion exhibited globule size of 48.4 nm and polydispersity index of 0.75. Carbopol® ETD 2020 could successfully gel the CMZ microemulsion without disturbing the structure. The CMZ-MBG showed significantly higher (P < 0.05) in vitro bioadhesion and antifungal activity as compared to that of Candid-V® gel. The stability studies indicated that CMZ undergoes acidic pH-catalyzed degradation at all the storage conditions at the end of 3 months.Key words: clotrimazole, microemulsion, microemulsion-based vaginal gel, stability studies, vaginal delivery 相似文献
10.
A novel approach to the design of sensitive fluorescent probes for nucleic acids detection is proposed. Suitable modifications of tri- and pentamethine cyanine dyes in the polymethine chain and/or in the heterocyclic residues can result in a significant decrease in unbound dye fluorescence intensity and an increase in dye emission intensity in the presence of DNA compared to the unsubstituted dye. The sharp enhancement in the fluorescence intensity upon dye interaction with double-stranded DNA permits the application of the modified tri- and pentamethine dyes as fluorescent probes in double-stranded DNA detection in homogeneous assays. 相似文献