Displaying publications 141 - 160 of 524 in total

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  1. Accumulation of heavy metals in freshwater molluscs
    Lau S, Mohamed M, Yen AT, Su'ut S
    Sci Total Environ, 1998 Jun 18;214:113-21.
    PMID: 9646520
    Heavy metals in the aquatic environment have to date come mainly from naturally occurring geochemical materials. However, this has been enhanced by human activity such as gold mining in the case of heavy metal pollution in Sg Sarawak Kanan. The high suspended solid loads in the river have quite efficiently removed most soluble metals from the water and trapped them in the bottom sediment. Three freshwater mollusc species were collected at the point source of the heavy metal pollutants and analysed for the heavy metal contents in their tissues and shells. Two of the mollusc species (Brotia costula and Melanoides tuberculata) are purely freshwater species while the Clithon sp. nr retropictus is able to survive in fresh and brackish water environments. The Brotia costula and the Clithon sp. are the edible species which are sold in the market. Accumulation of As, Cu, Fe, Se and Zn in all the three mollusc species were determined and the level of As in the tissues of Brotia costula and the Clithon sp. was much higher than the permissible level for human consumption. The mollusc species also demonstrated different preferences for the uptake of different metals. Variations in the heavy metal contents in the shell and tissues of the same species were also observed.
    Matched MeSH terms: Water Pollutants, Chemical/pharmacokinetics*; Metals, Heavy/pharmacokinetics*
  2. Simple high-performance liquid chromatographic method for the determination of metformin in human plasma
    Kah Hay Yuen, Kok Khiang Peh
    J Chromatogr B Biomed Sci Appl, 1998 Jun 12;710(1-2):243-6.
    PMID: 9686895
    A simple high-performance liquid chromatographic method using ultraviolet detection was developed for the determination of metformin in human plasma. The method entailed direct injection of the plasma sample after deproteination using perchloric acid. The mobile phase comprised 0.01 M potassium dihydrogen orthophosphate (pH 3.5) and acetonitrile (60:40, v/v). Analyses were run at a flow-rate of 1.0 ml/min with the detector operating at a detection wavelength of 234 nm. The method is specific and sensitive, with a quantification limit of approximately 60 ng/ml and a detection limit of 15 ng/ml at a signal-to-noise ratio of 3:1. The mean absolute recovery value was about 97%, while the within-day and between-day coefficient of variation and percent error values of the assay method were all less than 8%. The calibration curve was linear over a concentration range of 62.5-4000 ng/ml.
    Matched MeSH terms: Hypoglycemic Agents/pharmacokinetics; Metformin/pharmacokinetics
  3. Conversion from Sandimmune to Neoral in patients with stable renal allograft function: UHKL experience
    Goh BL, Jalil R, Koh SN, Chua CT, Tan SY
    Transplant Proc, 1998 Nov;30(7):3535-6.
    PMID: 9838548
    Matched MeSH terms: Immunosuppressive Agents/pharmacokinetics; Cyclosporine/pharmacokinetics
  4. Simple high-performance liquid chromatographic method for determination of ketoconazole in human plasma
    Yuen KH, Peh KK
    J Chromatogr B Biomed Sci Appl, 1998 Sep 18;715(2):436-40.
    PMID: 9792531
    A simple high-performance liquid chromatographic method using fluorescence detection was developed for the determination of ketoconazole in human plasma. The method entailed direct injection of the plasma sample after deproteinization using acetonitrile. The mobile phase comprised 0.05 M disodium hydrogen orthophosphate and acetonitrile (50:50, v/v) adjusted to pH 6. Analysis was run at a flow-rate of 1.5 ml/min with the detector operating at an excitation wavelength of 260 nm and an emission wavelength of 375 nm. The method is specific and sensitive with a quantification limit of approximately 60 ng/ml and a detection limit of 40 ng/ml at a signal-to-noise ratio of 3:1. Mean absolute recovery value was about 105%, while the within-day and between-day coefficient of variation and percent error values of the assay method were all less than 14%. The calibration curve was linear over a concentration range of 62.5-8000 ng/ml.
    Matched MeSH terms: Antifungal Agents/pharmacokinetics; Ketoconazole/pharmacokinetics
  5. Liquid chromatographic method for the determination of plasma itraconazole and its hydroxy metabolite in pharmacokinetic/bioavailability studies
    Wong JW, Nisar UR, Yuen KH
    J Chromatogr B Analyt Technol Biomed Life Sci, 2003 Dec 25;798(2):355-60.
    PMID: 14643517
    A sensitive and selective high-performance liquid chromatographic method was developed for the determination of itraconazole and its active metabolite, hydroxyitraconazole, in human plasma. Prior to analysis, both compounds together with the internal standard were extracted from alkalinized plasma samples using a 3:2 (v/v) mixture of 2,2,4-trimethylpentane and dichloromethane. The mobile phase comprised 0.02 M potassium dihydrogen phosphate-acetonitrile (1:1, v/v) adjusted to pH 3.0. Analysis was run at flow-rate of 0.9 ml/min with excitation and emission wavelengths set at 260 and 365 nm, respectively. Itraconazole was found to adsorb on glass or plastic tubes, but could be circumvented by prior treating the tubes using 10% dichlorodimethylsilane in toluene. Moreover, rinsing the injector port with acetonitrile helped to overcome any carry-over effect. This problem was not encountered with hydroxyitraconazole. The method was sensitive with limit of quantification of 3 ng/ml for itraconazole and 6 ng/ml for hydroxyitraconazole. The calibration curve was linear over a concentration range of 2.8-720 ng/ml for itraconazole and 5.6-720 ng/ml for the hydroxy metabolite. Mean recovery value of the extraction procedure for both compounds was about 85%, while the within-day and between-day coefficient of variation and percent error values of the assay method were all less than 15%. Hence, the method is suitable for use in pharmacokinetic and bioavailability studies of itraconazole.
    Matched MeSH terms: Antifungal Agents/pharmacokinetics; Itraconazole/pharmacokinetics
  6. Studies on the effect of translocation of chemical insecticides in Eicchornia host plant on Mansonia mosquitos--a potential control method
    Lee HL, Singh KI
    Southeast Asian J Trop Med Public Health, 1993;24 Suppl 2:105-9.
    PMID: 7526473
    A novel method for the control of Mansonia larvae was developed and tested. In this method, foliar absorption and translocation of a chemical insecticide, monocrotophos, a known systemic insecticide was studied in the Eicchornia plant. Acetone solution of the insecticide was painted onto leaves of the plant. At daily intervals, stems were severed and divided into equal sections which were introduced into bowls. Larvae of Aedes aegypti were tested for the presence of monocrotophos. It was found that translocation of the insecticide occurred at different rates in the stems and in some plants the chemical was also released into the surrounding water. Based on these results, 2 insecticides namely, monocrotophos and temephos were painted onto leaves of the host plant and their translocation to the root and water environment was examined by testing with Mansonia and Aedes aegypti larvae. The results again confirmed the translocation process and it was found that the insecticides were secreted into the surrounding water, thereby killing the larvae. However, in leaves painted with permethrin (synthetic pyrethroid) or flufenoxuron (chitin synthesis inhibitor), such a process was not detected. The potential of this new concept in Mansonia larval control is examined.
    Matched MeSH terms: Temefos/pharmacokinetics*; Monocrotophos/pharmacokinetics*
  7. How accurate and precise are limited sampling strategies in estimating exposure to mycophenolic acid in people with autoimmune disease?
    Abd Rahman AN, Tett SE, Staatz CE
    Clin Pharmacokinet, 2014 Mar;53(3):227-245.
    PMID: 24327238 DOI: 10.1007/s40262-013-0124-z
    Mycophenolic acid (MPA) is a potent immunosuppressant agent, which is increasingly being used in the treatment of patients with various autoimmune diseases. Dosing to achieve a specific target MPA area under the concentration-time curve from 0 to 12 h post-dose (AUC12) is likely to lead to better treatment outcomes in patients with autoimmune disease than a standard fixed-dose strategy. This review summarizes the available published data around concentration monitoring strategies for MPA in patients with autoimmune disease and examines the accuracy and precision of methods reported to date using limited concentration-time points to estimate MPA AUC12. A total of 13 studies were identified that assessed the correlation between single time points and MPA AUC12 and/or examined the predictive performance of limited sampling strategies in estimating MPA AUC12. The majority of studies investigated mycophenolate mofetil (MMF) rather than the enteric-coated mycophenolate sodium (EC-MPS) formulation of MPA. Correlations between MPA trough concentrations and MPA AUC12 estimated by full concentration-time profiling ranged from 0.13 to 0.94 across ten studies, with the highest associations (r (2) = 0.90-0.94) observed in lupus nephritis patients. Correlations were generally higher in autoimmune disease patients compared with renal allograft recipients and higher after MMF compared with EC-MPS intake. Four studies investigated use of a limited sampling strategy to predict MPA AUC12 determined by full concentration-time profiling. Three studies used a limited sampling strategy consisting of a maximum combination of three sampling time points with the latest sample drawn 3-6 h after MMF intake, whereas the remaining study tested all combinations of sampling times. MPA AUC12 was best predicted when three samples were taken at pre-dose and at 1 and 3 h post-dose with a mean bias and imprecision of 0.8 and 22.6 % for multiple linear regression analysis and of -5.5 and 23.0 % for maximum a posteriori (MAP) Bayesian analysis. Although mean bias was less when data were analysed using multiple linear regression, MAP Bayesian analysis is preferable because of its flexibility with respect to sample timing. Estimation of MPA AUC12 following EC-MPS administration using a limited sampling strategy with samples drawn within 3 h post-dose resulted in biased and imprecise results, likely due to a longer time to reach a peak MPA concentration (t max) with this formulation and more variable pharmacokinetic profiles. Inclusion of later sampling time points that capture enterohepatic recirculation and t max improved the predictive performance of strategies to predict EC-MPS exposure. Given the considerable pharmacokinetic variability associated with mycophenolate therapy, limited sampling strategies may potentially help in individualizing patient dosing. However, a compromise needs to be made between the predictive performance of the strategy and its clinical feasibility. An opportunity exists to combine research efforts globally to create an open-source database for MPA (AUC, concentrations and outcomes) that can be used and prospectively evaluated for AUC target-controlled dosing of MPA in autoimmune diseases.
    Matched MeSH terms: Antibiotics, Antineoplastic/pharmacokinetics*; Mycophenolic Acid/pharmacokinetics*
  8. Phytosterols as a natural anticancer agent: Current status and future perspective
    Shahzad N, Khan W, Md S, Ali A, Saluja SS, Sharma S, et al.
    Biomed Pharmacother, 2017 Apr;88:786-794.
    PMID: 28157655 DOI: 10.1016/j.biopha.2017.01.068
    Phytosterols are naturally occurring compounds in plants, structurally similar to cholesterol. The human diet is quite abundant in sitosterol and campesterol. Phytosterols are known to have various bioactive properties including reducing intestinal cholesterol absorption which alleviates blood LDL-cholesterol and cardiovascular problems. It is indicated that phytosterol rich diets may reduce cancer risk by 20%. Phytosterols may also affect host systems, enabling antitumor responses by improving immune response recognition of cancer, affecting the hormone dependent endocrine tumor growth, and by sterol biosynthesis modulation. Moreover, phytosterols have also exhibited properties that directly inhibit tumor growth, including reduced cell cycle progression, apoptosis induction, and tumor metastasis inhibition. The objective of this review is to summarize the current knowledge on occurrences, chemistry, pharmacokinetics and potential anticancer properties of phytosterols in vitro and in vivo. In conclusion, anticancer effects of phytosterols have strongly been suggested and support their dietary inclusion to prevent and treat cancers.
    Matched MeSH terms: Antineoplastic Agents, Phytogenic/pharmacokinetics; Phytosterols/pharmacokinetics
  9. Fulltext Focal uptake at the rotator interval or inferior capsule of shoulder on18F-FDG PET/CT is associated with adhesive capsulitis
    Sridharan R, Engle MP, Garg N, Wei W, Amini B
    Skeletal Radiol, 2017 Apr;46(4):533-538.
    PMID: 28161721 DOI: 10.1007/s00256-017-2587-8
    OBJECTIVE: To determine if focal increased uptake at the rotator interval (RI) and/or inferior capsule (IC) on18F-FDG PET/CT ("positive PET") predicts the presence of adhesive capsulitis (AC).

    MATERIALS AND METHODS: Three populations were retrospectively examined. Group 1 included 1,137 consecutive18F-FDG PET/CT studies and was used to determine the prevalence of focal uptake at the RI or IC. Group 2 included 361 cases from a 10-year period with18F-FDG PET/CT and MRI of shoulder performed within 45 days of each other and was used to enrich the study group. Group 3 included 109 randomly selected patients from the same time frame as groups 1 and 2 and was used to generate the control group. The study group consisted of 15 cases from the three groups, which had positive PET findings. PET/CT images were assessed in consensus by two musculoskeletal radiologists. The reference standard for a diagnosis of AC was clinical and was made by review of the medical record by a pain medicine physician.

    RESULTS: The prevalence of focal activity at either the RI or IC ("positive PET") was 0.53%. Nine patients had a clinical diagnosis of AC and 15 patients had a positive PET. The sensitivity and specificity of PET for detection of AC was 56% and 87%, respectively. PET/CT had a positive likelihood ratio for AC of 6.3 (95% CI: 2.8-14.6).

    CONCLUSIONS: Increased uptake at the RI or IC on PET/CT confers a moderate increase in the likelihood of AC.

    Matched MeSH terms: Radiopharmaceuticals/pharmacokinetics*; Fluorodeoxyglucose F18/pharmacokinetics*
  10. Bioequivalence of a generic metformin tablet preparation
    Yuen KH, Wong JW, Billa N, Julianto T, Toh WT
    Int J Clin Pharmacol Ther, 1999 Jul;37(7):319-22.
    PMID: 10442505
    The bioavailability of a generic preparation of metformin (Diabetmin from Hovid Sdn Bhd) was evaluated in comparison with a proprietary product (Glucophage from Lipha Pharma Ltd., UK).
    Matched MeSH terms: Hypoglycemic Agents/pharmacokinetics*; Metformin/pharmacokinetics*
  11. Method development and validation of a high-performance liquid chromatographic method for tramadol in human plasma using liquid-liquid extraction
    Gan SH, Ismail R, Wan Adnan WA, Wan Z
    J Chromatogr B Analyt Technol Biomed Life Sci, 2002 May 25;772(1):123-9.
    PMID: 12016023
    An HPLC system using a simple liquid-liquid extraction and HPLC with UV detection has been validated to determine tramadol concentration in human plasma. The method developed was selective and linear for concentrations ranging from 10 to 2000 ng/ml with average recovery of 98.63%. The limit of quantitation (LOQ) was 10 ng/ml and the percentage recovery of the internal standard phenacetin was 76.51%. The intra-day accuracy ranged from 87.55 to 105.99% and the inter-day accuracy, 93.44 to 98.43% for tramadol. Good precision (5.32 and 6.67% for intra- and inter-day, respectively) was obtained at LOQ. The method has been applied to determine tramadol concentrations in human plasma samples for a pharmacokinetic study.
    Matched MeSH terms: Analgesics, Opioid/pharmacokinetics; Tramadol/pharmacokinetics
  12. Comparative bioavailability study of two atenolol tablet preparations
    Peh KK, Yuen KH, Wong JW, Toh WT
    Drug Dev Ind Pharm, 1999 Mar;25(3):357-60.
    PMID: 10071830
    A study was conducted to compare the bioavailability of a generic product of atenolol (Normaten FC) with the innovator product, Tenormin. Twelve healthy adult volunteers participated in the study conducted according to a randomized, two-way crossover design. The preparations were compared using area under the plasma concentration-time curve AUC0-infinity, peak plasma concentration Cmax, and time to reach peak plasma concentration Tmax. No statistically significant difference was obtained between the Tmax values and the logarithmic transformed AUC0-infinity and Cmax values of the two products. Moreover, the 90% confidence interval for the ratio of the logarithmically transformed AUC0-infinity values of Normaten FC over those of Tenormin was found to lie between 0.82 and 0.98, while that of the logarithmically transformed Cmax values was between 0.82 and 1.09, both being within the bioequivalence limit of 0.80-1.25. The values of elimination half-life t1/2 between the two products were also found comparable and not significantly different statistically. The t1/2 values obtained in our study were slightly longer than those reported in the literature for other population groups.
    Matched MeSH terms: Adrenergic beta-Antagonists/pharmacokinetics*; Atenolol/pharmacokinetics*
  13. Comparative bioavailability study of a generic naltrexone tablet preparation
    Yuen KH, Peh KK, Billa N
    Drug Dev Ind Pharm, 1999 Mar;25(3):353-6.
    PMID: 10071829
    The bioavailability of a generic preparation of naltrexone (Narpan) was compared with the innovator product, Trexan. Twelve healthy volunteers participated in the study, conducted according to a completely randomized, two-way crossover design. The preparations were compared using the parameters area under the plasma concentration-time curve AUC0-infinity, peak plasma concentration Cmax, and time to reach peak plasma concentration Tmax. No statistically significant difference was observed between the logarithmic transformed AUC0-infinity and the logarithmically transformed Cmax values of the two preparations. Also, no statistically significant difference was observed between the untransformed Tmax values. In addition, the 90% confidence interval for the ratio of the logarithmic transformed AUC0-infinity values of Narpan over those of Trexan was found to lie between 0.87 and 1.01, while that of the logarithmic transformed Cmax values was between 0.94 and 1.23, both being within the bioequivalence limit of 0.80-1.25. The numerical values of the elimination half-life (t1/2) obtained with the two preparations were also not significantly different and were comparable to those reported in the literature.
    Matched MeSH terms: Naltrexone/pharmacokinetics*; Narcotic Antagonists/pharmacokinetics*
  14. Sorption of arsenate and arsenite anions by iron(III)-poly(hydroxamic acid) complex
    Haron MJ, Wan Yunus WM, Yong NL, Tokunaga S
    Chemosphere, 1999 Dec;39(14):2459-66.
    PMID: 10581698
    Iron(III)-poly(hydroxamic acid) resin complex has been studied for its sorption abilities with respect to arsenate and arsenite anions from an aqueous solution. The complex was found effective in removing the arsenate anion in the pH range of 2.0 to 5.5. The maximum sorption capacity was found to be 1.15 mmol/g. The sorption selectivity showed that arsenate sorption was not affected by chloride, nitrate and sulphate. The resin was tested and found effective for removal of arsenic ions from industrial wastewater samples.
    Matched MeSH terms: Arsenates/pharmacokinetics*; Arsenites/pharmacokinetics*
  15. Determination of artemether and dihydroartemisinin in blood plasma by high-performance liquid chromatography for application in clinical pharmacological studies
    Navaratnam V, Mansor SM, Chin LK, Mordi MN, Asokan M, Nair NK
    J Chromatogr B Biomed Appl, 1995 Jul 21;669(2):289-94.
    PMID: 7581905
    A selective reproducible high-performance liquid chromatographic assay for the simultaneous quantitative determination of the antimalarial compound artemether (ARM), dihydroartemisinin (DQHS) and artemisinin (QHS), as internal standard, is described. After extraction from plasma, ARM and DQHS were analysed using a Lichrocart/Lichrosphere 100 CN stainless-steel column and a mobile phase of acetonitrile-0.05 M acetic acid (15:85, v/v) adjusted to pH 5.0, and electrochemical detection in the reductive mode. The mean recovery of ARM and DQHS over a concentration range of 30-120 ng/ml was 81.6% and 93.4%, respectively. The within-day coefficients of variation were 0.89-7.01% for ARM and 3.45-8.11% for DQHS. The day-to-day coefficients of variation were 2.06-8.43% and 3.22-6.33%, respectively. The minimum detectable concentration for ARM and DQHS in plasma was 2.5 and 1.25 ng/ml for both compounds. The method was found to be suitable for use in clinical pharmacological studies.
    Matched MeSH terms: Antimalarials/pharmacokinetics; Sesquiterpenes/pharmacokinetics
  16. Fulltext Thermodynamic stability, in-vitro permeability, and in-silico molecular modeling of the optimal Elaeis guineensis leaves extract water-in-oil nanoemulsion
    Romes NB, Abdul Wahab R, Abdul Hamid M, Oyewusi HA, Huda N, Kobun R
    Sci Rep, 2021 10 21;11(1):20851.
    PMID: 34675286 DOI: 10.1038/s41598-021-00409-0
    Nanoemulsion is a delivery system used to enhance bioavailability of plant-based compounds across the stratum corneum. Elaeis guineensis leaves are rich source of polyphenolic antioxidants, viz. gallic acid and catechin. The optimal E. guineensis leaves extract water-in-oil nanoemulsion was stable against coalescence, but it was under significant influence of Ostwald ripening over 90 days at 25 °C. The in-vitro permeability revealed a controlled and sustained release of the total phenolic compounds (TPC) of EgLE with a cumulative amount of 1935.0 ± 45.7 µgcm-2 after 8 h. The steady-state flux and permeation coefficient values were 241.9 ± 5.7 µgcm-2 h-1 and 1.15 ± 0.03 cm.h-1, respectively. The kinetic release mechanism for TPC of EgLE was best described by the Korsmeyer-Peppas model due to the highest linearity of R2 = 0.9961, indicating super case II transport mechanism. The in-silico molecular modelling predicted that the aquaporin-3 protein in the stratum corneum bonded preferably to catechin over gallic acid through hydrogen bonds due to the lowest binding energies of - 57.514 kcal/mol and - 8.553 kcal/mol, respectively. Thus, the in-silico study further verified that catechin could improve skin hydration. Therefore, the optimal nanoemulsion could be used topically as moisturizer to enhance skin hydration based on the in-silico prediction.
    Matched MeSH terms: Emulsions/pharmacokinetics; Plant Extracts/pharmacokinetics
  17. Fate and cometabolic degradation of benzo[a]pyrene by white-rot fungus Armillaria sp. F022
    Hadibarata T, Kristanti RA
    Bioresour Technol, 2012 Mar;107:314-8.
    PMID: 22209445 DOI: 10.1016/j.biortech.2011.12.046
    Armillaria sp. F022, a white-rot fungus isolated from a tropical rain forest in Samarinda, Indonesia, was used to biodegrade benzo[a]pyrene (BaP). Transformation of BaP, a 5-ring polycyclic aromatic hydrocarbon (PAH), by Armillaria sp. F022, which uses BaP as a source of carbon and energy, was investigated. However, biodegradation of BaP has been limited because of its bioavailability and toxicity. Five cosubstrates were selected as cometabolic carbon and energy sources. The results showed that Armillaria sp. F022 used BaP with and without cosubstrates. A 2.5-fold increase in degradation efficiency was achieved after addition of glucose. Meanwhile, the use of glucose as a cosubstrate could significantly stimulate laccase production compared with other cosubstrates and not using any cosubstrate. The metabolic pathway was elucidated by identifying metabolites, conducting biotransformation studies, and monitoring enzyme activities in cell-free extracts. The degradation mechanism was determined through the identification of several metabolites: benzo[a]pyrene-1,6-quinone, 1-hydroxy-2-benzoic acid, and benzoic acid.
    Matched MeSH terms: Benzo(a)pyrene/pharmacokinetics; Environmental Pollutants/pharmacokinetics
  18. Formulation of diclofenac for dermal delivery
    Goh CF, Lane ME
    Int J Pharm, 2014 Oct 1;473(1-2):607-16.
    PMID: 25091375 DOI: 10.1016/j.ijpharm.2014.07.052
    Diclofenac (DF) was first synthesized in the 1960's and is currently available as ophthalmic, oral, parenteral, rectal and skin preparations. This review focuses on the administration of DF to the skin. As a member of the non-steroidal anti-inflammatory (NSAID) group of drugs the primary indications of DF are for the management of inflammation and pain but it is also used to treat actinic keratosis. The specific aims of this paper are to: (i) provide an overview of the pharmacokinetics and metabolism of DF following oral and topical administration; (ii) examine critically the various formulation approaches which have been investigated to enhance dermal delivery of DF; and (iii) identify new formulation strategies for enhanced DF skin penetration.
    Matched MeSH terms: Anti-Inflammatory Agents, Non-Steroidal/pharmacokinetics; Diclofenac/pharmacokinetics
  19. Fulltext Development and validation of a bioanalytical method for quantification of 2,6-bis-(4-hydroxy-3-methoxybenzylidene)-cyclohexanone (BHMC) in rat plasma
    Lee YZ, Ming-Tatt L, Lajis NH, Sulaiman MR, Israf DA, Tham CL
    Molecules, 2012 Dec 07;17(12):14555-64.
    PMID: 23222902 DOI: 10.3390/molecules171214555
    A sensitive and accurate high performance liquid chromatography with ultraviolet/visible light detection (HPLC-UV/VIS) method for the quantification of 2,6-bis-(4-hydroxy-3-methoxybenzylidene)-cyclohexanone (BHMC) in rat plasma was developed and validated. BHMC and the internal standard, harmaline, were extracted from plasma samples by a simple liquid-liquid extraction using 95% ethyl acetate and 5% methanol. Plasma concentration of BHMC and internal standard were analyzed by reversed phase chromatography using a C₁₈ column (150 × 4.6 mm I.D., particle size 5 µm) and elution with a gradient mobile phase of water and methanol at a flow rate of 1.0 mL/min. Detection of BHMC and internal standard was done at a wavelength of 380 nm. The limit of quantification was 0.02 µg/mL. The calibration curves was linear (R² > 0.999) over the concentration range of 0.02-2.5 µg/mL. Intra- and inter-day precision were less than 2% coefficient of variation. The validated method was then applied to a pharmacokinetic study in rats by intravenous administration of BHMC at a single dose of 10 mg/kg. Pharmacokinetic parameters such as half-life, maximum plasma concentration, volume of distribution, clearance and elimination rate constant for BHMC were calculated.
    Matched MeSH terms: Curcumin/pharmacokinetics; Cyclohexanones/pharmacokinetics
  20. Bromophenol blue binding to mammalian albumins and displacement of albumin-bound bilirubin
    Kim BB, Abdul Kadir H, Tayyab S
    Pak J Biol Sci, 2008 Oct 15;11(20):2418-22.
    PMID: 19137852
    Interaction of bromophenol blue (BPB) with serum albumins from different mammalian species, namely, human (HSA), bovine (BSA), goat (GSA), sheep (SSA), rabbit (RbSA), porcine (PSA) and dog (DSA) was studied using absorption and absorption difference spectroscopy. BPB-albumin complexes showed significant differences in the spectral characteristics, i.e., extent of bathochromic shift and hypochromism relative to the spectral features of free BPB. Absorption difference spectra of these complexes also showed variations in the position of maxima and absorption difference (deltaAbs.) values. Absorption difference spectra of different bilirubin (BR)-albumin complexes showed a significant blue shift accompanied by decrease in deltaAbs. values in presence of BPB which were indicative of the displacement of bound BR from its binding site in BR-albumin complexes. These changes in the difference spectral characteristics of BR-albumin complexes were more marked at higher BPB concentration. However, the extent of these changes was different for different BR-albumin complexes. Taken together, all these results suggest that BPB partially shares BR binding site on albumin and different mammalian albumins show differences in the microenvironment of the BR/BPB binding site.
    Matched MeSH terms: Bromphenol Blue/pharmacokinetics*; Coloring Agents/pharmacokinetics
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