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Sources of sedimentary PAHs in tropical Asian waters: differentiation between pyrogenic and petrogenic sources by alkyl homolog abundance

Saha M, Togo A, Mizukawa K, Murakami M, Takada H, Zakaria MP, et al.

Mar Pollut Bull, 2009 Feb;58(2):189-200.
PMID: 19117577 DOI: 10.1016/j.marpolbul.2008.04.049

We collected surface sediment samples from 174 locations in India, Indonesia, Malaysia, Thailand, Vietnam, Cambodia, Laos, and the Philippines and analyzed them for polycyclic aromatic hydrocarbons (PAHs) and hopanes. PAHs were widely distributed in the sediments, with comparatively higher concentrations in urban areas (Sigma PAHs: approximately 1000 to approximately 100,000 ng/g-dry) than in rural areas ( approximately 10 to approximately 100g-dry), indicating large sources of PAHs in urban areas. To distinguish petrogenic and pyrogenic sources of PAHs, we calculated the ratios of alkyl PAHs to parent PAHs: methylphenanthrenes to phenanthrene (MP/P), methylpyrenes+methylfluoranthenes to pyrene+fluoranthene (MPy/Py), and methylchrysenes+methylbenz[a]anthracenes to chrysene+benz[a]anthracene (MC/C). Analysis of source materials (crude oil, automobile exhaust, and coal and wood combustion products) gave thresholds of MP/P=0.4, MPy/Py=0.5, and MC/C=1.0 for exclusive combustion origin. All the combustion product samples had the ratios of alkyl PAHs to parent PAHs below these threshold values. Contributions of petrogenic and pyrogenic sources to the sedimentary PAHs were uneven among the homologs: the phenanthrene series had a greater petrogenic contribution, whereas the chrysene series had a greater pyrogenic contribution. All the Indian sediments showed a strong pyrogenic signature with MP/P approximately 0.5, MPy/Py approximately 0.1, and MC/C approximately 0.2, together with depletion of hopanes indicating intensive inputs of combustion products of coal and/or wood, probably due to the heavy dependence on these fuels as sources of energy. In contrast, sedimentary PAHs from all other tropical Asian cities were abundant in alkylated PAHs with MP/P approximately 1-4, MPy/Py approximately 0.3-1, and MC/C approximately 0.2-1.0, suggesting a ubiquitous input of petrogenic PAHs. Petrogenic contributions to PAH homologs varied among the countries: largest in Malaysia whereas inferior in Laos. The higher abundance of alkylated PAHs together with constant hopane profiles suggests widespread inputs of automobile-derived petrogenic PAHs to Asian waters.

Matched MeSH terms: Reference Standards
Monitoring of free glutamic acid in Malaysian processed foods, dishes and condiments

Khairunnisak M, Azizah AH, Jinap S, Nurul Izzah A

Food Addit Contam Part A Chem Anal Control Expo Risk Assess, 2009 Apr;26(4):419-26.
PMID: 19680916 DOI: 10.1080/02652030802596860

A study to quantify the free glutamic acid content of six processed foods, 44 dishes and 26 condiments available in Malaysia was performed using high-performance liquid chromatography with a fluorescence detector (HPLC-FRD). Recovery tests were carried out with spiked samples at levels from 6 to 31 mg g(-1). High recovery in different matrices was achieved ranging from 88% +/- 13% to 102% +/- 5.12%, with an average of 97% +/- 8.92%. Results from the study revealed that the average free glutamic acid content ranged from 0.34 +/- 0.20 to 4.63 +/- 0.41 mg g(-1) in processed foods, while in prepared dishes it was as low as 0.24 +/- 0.15 mg g(-1) in roti canai (puffed bread served with curry or dhal) to 8.16 +/- 1.99 mg g(-1) in dim sum (a small casing of dough, usually filled with minced meat, seafood, and vegetables, either steamed or fried). Relatively, the content of free glutamic acid was found to be higher in condiments at 0.28 +/- 0 mg g(-1) in mayonnaise to 170.90 +/- 6.40 mg g(-1) in chicken stock powder.

Matched MeSH terms: Reference Standards
Determination of quinocide as impurity in primaquine tablets by capillary zone electrophoresis

Elbashir AA, Saad B, Ali AS, Saleh MI, Aboul-Enein HY

Biomed Chromatogr, 2009 May;23(5):464-71.
PMID: 19016231 DOI: 10.1002/bmc.1137

A capillary zone electrophoretic method has been developed and validated for the determination of the impurity quinocide (QC) in the antimalarial drug primaquine (PQ). Different buffer additives such as native cyclodextrins and crown ethers were evaluated. Promising results were obtained when either beta-cyclodextrin (beta-CD) or 18-crown-6 ether (18C6) were used. Their separation conditions such as type of buffer and its pH, buffer additive concentration, applied voltage capillary temperature and injection time were optimized. The use of 18C6 offers slight advantages over beta-CD such as faster elution times and improved resolution. Nevertheless, migration times of less than 5 min and resolution factors (R(s)) in the range of 2-4 were obtained when both additives were used. The method was validated with respect to selectivity, linearity, limits of detection and quantitation, analytical precision (intra- and inter-day variability) and repeatability. Concentrations of 2.12 and 2.71% (w/w) of QC were found in pharmaceutical preparations of PQ from two different manufacturers. A possible mechanism for the successful separation of the isomers is also discussed.

Matched MeSH terms: Reference Standards
Optimizing conditions for methylmercury extraction from fish samples for GC analysis using response surface methodology

Hajeb P, Jinap S, Abu Bakar F, Bakar J

Food Addit Contam Part A Chem Anal Control Expo Risk Assess, 2009 Jun;26(6):829-38.
PMID: 19680957 DOI: 10.1080/02652030902751704

Response surface methodology (RSM) was used to determine the optimum experimental conditions to extract methylmercury from fish samples for GC analysis. The influence of four variables - acid concentration (3-12 M), cysteine concentration (0.5-2% w/v), solvent volume (3-9 ml) and extraction time (10-30 min) - on recovery of methylmercury was evaluated. The detection limit for methylmercury analysis using a microelectron capture detector was 7 ng g(-1) in fish samples. The mean recovery under optimum conditions was 94%. Experimental data were adequately fitted into a second-order polynomial model with multiple regression coefficients (r(2)) of 0.977. The four variables had a significant effect (p < 0.05) on the recovery of methylmercury from a reference material (BCR-463). Optimum conditions for methylmercury extraction were found using an acid concentration of 12.2 M, cysteine concentration of 2.4%, solvent volume of 1.5 ml and extraction time of 35 min. The validation of the developed method to analyze methylmercury in fish samples exhibited good agreement with mercury content in the samples.

Matched MeSH terms: Reference Standards
Validation of an enzyme-linked immunosorbent assay screening method and a liquid chromatography-tandem mass spectrometry confirmation method for the identification and quantification of ketamine and norketamine in urine samples from Malaysia

Harun N, Anderson RA, Miller EI

J Anal Toxicol, 2009 8 6;33(6):310-21.
PMID: 19653934 DOI: 10.1093/jat/33.6.310

An ELISA and a liquid chromatography-tandem mass spectrometry (LC-MS-MS) confirmation method were developed and validated for the identification and quantitation of ketamine and its major metabolite norketamine in urine samples. The Neogen ketamine microplate ELISA was optimized with respect to sample and enzyme conjugate volumes and the sample preincubation time before addition of the enzyme conjugate. The ELISA kit was validated to include an assessment of the dose-response curve, intra- and interday precision, limit of detection (LOD), and cross-reactivity. The sensitivity and specificity were calculated by comparison to the results from the validated LC-MS-MS confirmation method. An LC-MS-MS method was developed and validated with respect to LOD, lower limit of quantitation (LLOQ), linearity, recovery, intra- and interday precision, and matrix effects. The ELISA dose-response curve was a typical S-shaped binding curve, with a linear portion of the graph observed between 25 and 500 ng/mL for ketamine. The cross-reactivity of 200 ng/mL norketamine to ketamine was 2.1%, and no cross-reactivity was detected with 13 common drugs tested at 10,000 ng/mL. The ELISA LOD was calculated to be 5 ng/mL. Both intra- (n = 10) and interday (n = 50) precisions were below 5.0% at 25 ng/mL. The LOD for ketamine and norketamine was calculated statistically to be 0.6 ng/mL. The LLOQ values were also calculated statistically and were 1.9 ng/mL and 2.1 ng/mL for ketamine and norketamine, respectively. The test linearity was 0-1200 ng/mL with correlation coefficient (R(2)) > 0.99 for both analytes. Recoveries at 50, 500, and 1000 ng/mL range from 97.9% to 113.3%. Intra- (n = 5) and interday (n = 25) precisions between extracts for ketamine and norketamine were excellent (< 10%). Matrix effects analysis showed an average ion suppression of 5.7% for ketamine and an average ion enhancement of 13.0% for norketamine for urine samples collected from six individuals. A comparison of ELISA and LC-MS-MS results demonstrated a sensitivity, specificity, and efficiency of 100%. These results indicated that a cutoff value of 25 ng/mL ketamine in the ELISA screen is particularly suitable and reliable for urine testing in a forensic toxicology setting. Furthermore, both ketamine and norketamine were detected in all 34 urine samples collected from individuals socializing in pubs by the Royal Malaysian Police. Ketamine concentrations detected by LC-MS-MS ranged from 22 to 31,670 ng/mL, and norketamine concentrations ranged from 25 to 10,990 ng/mL. The concentrations of ketamine and norketamine detected in the samples are most ikely indicative of ketamine abuse.

Matched MeSH terms: Reference Standards
Simultaneous determination of ofloxacin and ornidazole in pharmaceutical preparations by capillary zone electrophoresis

See KL, Elbashir AA, Saad B, Ali AS, Aboul-Enein HY

Biomed Chromatogr, 2009 Dec;23(12):1283-90.
PMID: 19488980 DOI: 10.1002/bmc.1251

A simple, rapid and validated capillary electrophoretic method has been developed for the separation and determination of ofloxacin and ornidazole in pharmaceutical formulations with detection at 230 nm. Optimal conditions for the quantitative separations were investigated. Analysis times shorter than 4 min were obtained using a background electrolyte solution consisting of 25 mmol/L phosphoric acid adjusted with 1 M Tris buffer to pH 8.5, with hydrodynamic injection of 5 s and 20 kV separation voltage. The validation criteria for accuracy, precision, linearity and limits of detection and quantitation were examined and discussed. An excellent linearity was obtained in concentration range 25-250 microg/mL. The detection limits for ofloxacin and ornidazole were 1.03 +/- 0.11 and 1.80 +/- 0.06 microg/mL, respectively. The proposed method has been applied for the analysis of ofloxacin and ornidazole both individually and in a combined dosage tablet formulation. The proposed validated method showed recoveries between 96.16 and 105.23% of the nominal contents.

Matched MeSH terms: Reference Standards
Fulltext Software development for optimal design of different precast slabs

Noorzaei, J., Wong, J.N., Thanoon, W.A., Jaafar, M.S.

Pertanika Journal of Science & Technology, 2009;17(1):-.
MyJurnal

Precast concrete technology forms an important part in the drive towards a full implementation of the Industrialized Building System (IBS). The IBS requires building components and their dimensions to be standardized, and preferably cast off site. Slabs are major structural elements in buildings, other than beams and columns. Standardized and optimized slabs can significantly enhance the building industries in achieving the full implementation of the IBS. Nevertheless, this requires computer techniques to achieve standardized and optimized slabs which can satisfy all building design requirements, including the standards of architectural and structural design standards. This study proposed a computer technique which analysed and designed five different types of slabs which will satisfy all the requirements in design. The most commonly used slabs included in this study were the solid one way, solid two way, ribbed, voided and composite slabs. The computer techniques enable the design of the most optimized sections for any of the slab types under any loading and span conditions. The computer technique also provides details for the reinforcements required for the slabs.

Matched MeSH terms: Reference Standards
Effects of season on the yield and quality of extracts from Gracilaria changii (Gracilariaceae, Rhodophyta)

Sasidharan S, Darah I, Jain K

Sains Malaysiana, 2009;38.

The effect of season on yield and quality of organic solvent extracts from Gracilaria changii was determined. The sustainability of the bioactive compound of G. changii from Malaysia was investigated by using the TLC and FTIR standards methods. Studies was carried out to examine the sustainability of the bioactive compound in the various extract obtained from G. changii collected from Pantai Morib, Beach Selangor Malaysia on bimonthly for a period of one year in 2003. This study revealed that the bioactive compounds was present all over the year but with different quantities. In general the variation in yield or quantities of bioactive compound was related to environment. G. changii can be considered a candidate for drug development since it retained the number of bioactive compound.

Matched MeSH terms: Reference Standards
Comparison of signal-to-noise, blank determination, and linear regression methods for the estimation of detection and quantification limits for volatile organic compounds by gas chromatography

Sanagi MM, Ling SL, Nasir Z, Hermawan D, Ibrahim WA, Abu Naim A

J AOAC Int, 2010 2 20;92(6):1833-8.
PMID: 20166602

LOD and LOQ are two important performance characteristics in method validation. This work compares three methods based on the International Conference on Harmonization and EURACHEM guidelines, namely, signal-to-noise, blank determination, and linear regression, to estimate the LOD and LOQ for volatile organic compounds (VOCs) by experimental methodology using GC. Five VOCs, toluene, ethylbenzene, isopropylbenzene, n-propylbenzene, and styrene, were chosen for the experimental study. The results indicated that the estimated LODs and LOQs were not equivalent and could vary by a factor of 5 to 6 for the different methods. It is, therefore, essential to have a clearly described procedure for estimating the LOD and LOQ during method validation to allow interlaboratory comparisons.

Matched MeSH terms: Reference Standards
Dosing information in a standard drug reference: are pediatrics still therapeutically neglected?

Permala J, Hassali MA, Awaisu A, Shafie AA

Pediatr Int, 2010 Apr;52(2):290-5.
PMID: 19744224 DOI: 10.1111/j.1442-200X.2009.02958.x

BACKGROUND: In many countries, the most readily accessible drug information resources, such as the Monthly Index of Medical Specialties (MIMS), lack information concerning use in children. We reviewed the product information (PI) of medications in the most widely used drug information reference in Malaysia in an effort to determine the extent and the nature of available information related to pediatric dosing.
METHODS: The products listed in the 2007 Malaysian MIMS Annual were reviewed for PI on pediatric use as per inclusion and exclusion criteria. The dosing information for each PI was extracted according to age groups. Product information that claimed suitability for use in pediatrics was further evaluated for information on pediatric dosage formulations.
RESULTS: A total of 421 PI items from seven categories of therapeutic classes were reviewed. Of these, 69% gave inadequate pediatric dosing information. The proportions, for each age group of PI items that gave adequate pediatric dosing information were: neonates (13.1%), infants (23.3%), and children (32.2%). Therapeutic classes of drugs differed significantly in terms of dosing information adequacy for all pediatric age groups (P < 0.05). Most PI reviewed under all legal categories provided inadequate pediatric dosing information, but suitable pediatric formulations were commonly (70.1-85.5%) available where the dosing information existed. Overall, category B (prescription only) products did not differ significantly from category C (pharmacy only medicine) products in terms of pediatric dosing information adequacy, except for children.
CONCLUSION: This study has managed to contribute substantial additional information regarding the extent of pediatric dosing information and dosage formulations available in the MIMS Annual, stressing that the majority of PI for the products reviewed did not provide adequate dosing information for pediatric patients, subjecting this population to a therapeutically disadvantaged status.

Matched MeSH terms: Reference Standards
RBC-Y/MCV as a discriminant function for differentiating carriers of thalassaemia and HbE from iron deficiency

Nadarajan VS, Sthaneshwar P, Jayaranee S

Int J Lab Hematol, 2010 Apr;32(2):215-21.
PMID: 19566741 DOI: 10.1111/j.1751-553X.2009.01174.x

Individuals with alpha-thalassaemia (ATT), beta-thalassaemia (BTT) and HbE trait (HET) are often initially identified based on haematological parameters. However, the values of these parameters usually overlap with iron deficiency anaemia (IDA) and anaemia of chronic disease (ACD). We evaluated the use of RBC-Y in 156 normal individuals and 332 patients; ATT (n = 37), BTT (n = 61), HET (n = 25), HbH disease (n = 5), ACD (n = 67), IDA (n = 83) and ACD with IDA (n = 54). Diagnostic efficiency was analysed by receiver operating characteristics (ROC). MCH was better compared with RBC-Y in discriminating normal from abnormal with sensitivity and specificity of 94% at a cut-off of 26 pg. The Green and King (G&K) index performed the best in discriminating carriers from IDA and ACD with area under the ROC curve (AUC(ROC)) of 0.81. However, if ACD was excluded, RBC-Y/MCV was a good discriminator for carriers from IDA with AUC(ROC) = 0.845. In general screening of populations with ATT, BTT and HET, we propose that hypochromic individuals be first identified by MCH <26 pg and carriers distinguished within these hypochromic individuals from IDA by using RBC-Y/MCV. However, if the prevalence of ACD were high within the screening population, G&K index would be a more suitable discriminator.

Matched MeSH terms: Reference Standards
Effects of partially hydrogenated, semi-saturated, and high oleate vegetable oils on inflammatory markers and lipids

Teng KT, Voon PT, Cheng HM, Nesaretnam K

Lipids, 2010 May;45(5):385-92.
PMID: 20437207 DOI: 10.1007/s11745-010-3416-1

Knowledge about the effects of dietary fats on subclinical inflammation and cardiovascular disease risk are mainly derived from studies conducted in Western populations. Little information is available on South East Asian countries. This current study investigated the chronic effects on serum inflammatory markers, lipids, and lipoproteins of three vegetable oils. Healthy, normolipidemic subjects (n = 41; 33 females, 8 males) completed a randomized, single-blind, crossover study. The subjects consumed high oleic palm olein (HOPO diet: 15% of energy 18:1n-9, 9% of energy 16:0), partially hydrogenated soybean oil (PHSO diet: 7% of energy 18:1n-9, 10% of energy 18:1 trans) and an unhydrogenated palm stearin (PST diet: 11% of energy 18:1n-9, 14% of energy 16:0). Each dietary period lasted 5 weeks with a 7 days washout period. The PHSO diet significantly increased serum concentrations of high sensitivity C-reactive protein compared to HOPO and PST diets (by 26, 23%, respectively; P < 0.05 for both) and significantly decreased interleukin-8 (IL-8) compared to PST diet (by 12%; P < 0.05). In particular PHSO diet, and also PST diet, significantly increased total:HDL cholesterol ratio compared to HOPO diet (by 23, 13%, respectively; P < 0.05), with the PST diet having a lesser effect than the PHSO diet (by 8%; P < 0.05). The use of vegetable oils in their natural state might be preferred over one that undergoes the process of hydrogenation in modulating blood lipids and inflammation.

Matched MeSH terms: Reference Standards
Fulltext Standardization of Cassia spectabilis with respect to authenticity, assay and chemical constituent analysis

Torey A, Sasidharan S, Yeng C, Latha LY

Molecules, 2010 May 10;15(5):3411-20.
PMID: 20657490 DOI: 10.3390/molecules15053411

Quality control standardizations of the various medicinal plants used in traditional medicine is becoming more important today in view of the commercialization of formulations based on these plants. An attempt at standardization of Cassia spectabilis leaf has been carried out with respect to authenticity, assay and chemical constituent analysis. The authentication involved many parameters, including gross morphology, microscopy of the leaves and functional group analysis by Fourier Transform Infrared (FTIR) spectroscopy. The assay part of standardization involved determination of the minimum inhibitory concentration (MIC) of the extract which could help assess the chemical effects and establish curative values. The MIC of the C. spectabilis leaf extracts was investigated using the Broth Dilution Method. The extracts showed a MIC value of 6.25 mg/mL, independent of the extraction time. The chemical constituent aspect of standardization involves quantification of the main chemical components in C. spectabilis. The GCMS method used for quantification of 2,4-(1H,3H)-pyrimidinedione in the extract was rapid, accurate, precise, linear (R(2) = 0.8685), rugged and robust. Hence this method was suitable for quantification of this component in C. spectabilis. The standardization of C. spectabilis is needed to facilitate marketing of medicinal plants, with a view to promoting the export of valuable Malaysian Traditional Medicinal plants such as C. spectabilis.

Matched MeSH terms: Reference Standards
Application of multiplex PCR for characterization of human embryonic stem cells (hESCs) and its differentiated progenies

Mamidi MK, Pal R, Bhonde R, Zakaria Z, Totey S

J Biomol Screen, 2010 Jul;15(6):630-43.
PMID: 20530724 DOI: 10.1177/1087057110370211

Techniques to evaluate gene expression profiling, including real-time quantitative PCR, TaqMan low-density arrays, and sufficiently sensitive cDNA microarrays, are efficient methods for monitoring human embryonic stem cell (hESC) cultures. However, most of these high-throughput tests have a limited use due to high cost, extended turnaround time, and the involvement of highly specialized technical expertise. Hence, there is a paucity of rapid, cost-effective, robust, yet sensitive methods for routine screening of hESCs. A critical requirement in hESC cultures is to maintain a uniform undifferentiated state and to determine their differentiation capacity by showing the expression of gene markers representing all germ layers, including ecto-, meso-, and endoderm. To quantify the modulation of gene expression in hESCs during their propagation, expansion, and differentiation via embryoid body (EB) formation, the authors developed a simple, rapid, inexpensive, and definitive multimarker, semiquantitative multiplex RT-PCR (mxPCR) platform technology. Among the 15 gene primers tested, 4 were pluripotent markers comprising set 1, and 3 lineage-specific markers from each ecto-, meso-, and endoderm layers were combined as sets 2 to 4, respectively. The authors found that these 4 sets were not only effective in determining the relative differentiation in hESCs, but were easily reproducible. In this study, they used the HUES-7 cell line to standardize the technique, which was subsequently validated with HUES-9, NTERA-2, and mouse embryonic fibroblast cells. This single-reaction mxPCR assay was flexible and, by selecting appropriate reporter genes, can be designed for characterization of different hESC lines during routine maintenance and directed differentiation.

Matched MeSH terms: Reference Standards
Fulltext Evaluation of two commercially available ELISAs for the diagnosis of Japanese encephalitis applied to field samples

Lewthwaite P, Shankar MV, Tio PH, Daly J, Last A, Ravikumar R, et al.

Trop Med Int Health, 2010 Jul;15(7):811-8.
PMID: 20487425 DOI: 10.1111/j.1365-3156.2010.02537.x

OBJECTIVE: To compare two commercially available kits, Japanese Encephalitis-Dengue IgM Combo ELISA (Panbio Diagnostics) and JEV-CheX IgM capture ELISA (XCyton Diagnostics Limited), to a reference standard (Universiti Malaysia Sarawak - Venture Technologies VT ELISA).
METHODS: Samples were obtained from 172/192 children presenting to a site in rural India with acute encephalitis syndrome.
RESULTS: Using the reference VT ELISA, infection with Japanese encephalitis virus (JEV) was confirmed in 44 (26%) patients, with central nervous system infection confirmed in 27 of these; seven patients were dengue seropositive. Of the 121 remaining patients, 37 (31%) were JEV negative and 84 (69%) were JEV unknown because timing of the last sample tested was <10 day of illness or unknown. For patient classification with XCyton, using cerebrospinal fluid alone (the recommended sample), sensitivity was 77.8% (59.2-89.4) with specificity of 97.3% (90.6-99.2). For Panbio ELISA, using serum alone (the recommended sample), sensitivity was 72.5% (57.2-83.9) with specificity of 97.5% (92.8-99.1). Using all available samples for patient classification, sensitivity and specificity were 63.6% (95% CI: 48.9-76.2) and 98.4% (94.5-99.6), respectively, for XCyton ELISA and 75.0% (59.3-85.4) and 97.7% (93.3-99.2) for Panbio ELISA.
CONCLUSION: The two commercially available ELISAs had reasonable sensitivities and excellent specificities for diagnosing JEV.

Matched MeSH terms: Reference Standards
Fulltext Pharmaceutical quality of nine generic orlistat products compared with Xenical(r)

Taylor PW, Arnet I, Fischer A, Simpson IN

Obes Facts, 2010 Aug;3(4):231-7.
PMID: 20823686 DOI: 10.1159/000319450

OBJECTIVE: To compare the pharmaceutical quality of Xenical (chemically produced orlistat) with nine generic products, each produced by fermentation processes.
METHODS: Xenical 120 mg capsules (Roche, Basel, Switzerland) were used as reference material. Generic products were from India, Malaysia, Argentina, Philippines, Uruguay, and Taiwan. Colour, melting temperature, crystalline form, particle size, capsule fill mass, active pharmaceutical ingredient content, amount of impurities, and dissolution were compared. Standard physical and chemical laboratory tests were those developed by Roche for Xenical.
RESULTS: All nine generic products failed the Xenical specifications in four or more tests, and two generic products failed in seven tests. A failure common to all generic products was the amount of impurities present, mostly due to different by-products, including side-chain homologues not present in Xenical. Some impurities were unidentified. Two generic products tested failed the dissolution test, one product formed a capsule-shaped agglomerate on storage and resulted in poor (=15%) dissolution. Six generic products were powder formulations.
CONCLUSIONS: All tested generic orlistat products were pharmaceutically inferior to Xenical. The high levels of impurities in generic orlistat products are a major safety and tolerability concern.

Matched MeSH terms: Reference Standards
Fulltext Antiplatelet aggregation and platelet activating factor (PAF) receptor antagonistic activities of the essential oils of five Goniothalamus species

Moharam BA, Jantan I, Ahmad Fb, Jalil J

Molecules, 2010 Aug;15(8):5124-38.
PMID: 20714290 DOI: 10.3390/molecules15085124

Nine essential oils, hydrodistilled from different parts of five Goniothalamus species (G. velutinus Airy-Shaw, G. woodii Merr., G. clemensii Ban, G. tapis Miq. and G. tapisoides Mat Salleh) were evaluated for their ability to inhibit platelet aggregation in human whole blood using an electrical impedance method and their inhibitory effects on platelet activating factor (PAF) receptor binding with rabbit platelets using 3H-PAF as a ligand. The chemical composition of the oils was analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The bark oil of G. velutinus was the most effective sample as it inhibited both arachidonic acid (AA) and ADP-induced platelet aggregation with IC(50) values of 93.6 and 87.7 microg/mL, respectively. Among the studied oils, the bark oils of G. clemensii, G. woodii, G. velutinus and the root oil of G. tapis showed significant inhibitory effects on PAF receptor binding, with IC(50 )values ranging from 3.5 to 10.5 microg/mL. The strong PAF antagonistic activity of the active oils is related to their high contents of sesquiterpenes and sesquiterpenoids, and the individual components in the oils could possibly produce a synergistic effect in the overall antiplatelet activity of the oils.

Matched MeSH terms: Reference Standards
A 4-hydroxy-N'-[(E)-(2-hydroxyphenyl)methylidene]benzohydrazide-based sorbent material for the extraction-HPLC determination of biogenic amines in food samples

Tameem AA, Saad B, Makahleh A, Salhin A, Saleh MI

Talanta, 2010 Sep 15;82(4):1385-91.
PMID: 20801345 DOI: 10.1016/j.talanta.2010.07.004

A sorbent material based on a newly synthesized hydrazone ligand, 4-hydroxy-N'-[(E)-(2-hydroxyphenyl)methylidene]benzohydrazide was prepared by immobilizing the ligand into a silica sol-gel matrix. The capability of the sorbent material for the extraction of seven biogenic amines (BAs), i.e., tryptamine (TRY), beta-phenylethylamine (PEA), putrescine (PUT), cadaverine (CAD), histamine (HIS), tyramine (TYR), and spermidine (SPD) was studied. Under the adopted conditions, the sorbent showed good selectivity towards PUT, CAD, HIS and SPD (% extraction (%E)>96) while %E for TYR, TRY and PEA were 82.0, 78.9 and 46.4%, respectively. The sorbent could be used up to six extraction cycles for SPD, CAD and PUT and was applied to the determination of food samples ("budu", ketchup, orange juice, soy sauce) that were spiked with 20 mg L(-1) of the BAs. The extracted analytes were derivatized with dansyl chloride before the HPLC determination. With the exception of HIS and TYR in "budu" sample, reasonable recoveries were found for the other analytes in all the tested food samples.

Matched MeSH terms: Reference Standards
Comparative study on open system digestion and microwave assisted digestion methods for metal determination in shrimp sludge compost

Nemati K, Abu Bakar NK, Bin Abas MR, Sobhanzadeh E, Low KH

J Hazard Mater, 2010 Oct 15;182(1-3):453-9.
PMID: 20638781 DOI: 10.1016/j.jhazmat.2010.06.053

The aim of this work was to evaluate two different digestion methods for the determination of the total concentration of metals (Zn, Cu, Cr, Ni, Pb and Cd) in shrimp sludge compost. The compost made from shrimp aquaculture sludge co-composted with organic materials (peat, crushed bark and manure) was used as an organic growing medium for crop. Open system digestion and microwave assisted digestion procedures were employed in sample preparation. Various combinations and volumes of hydrofluoric, nitric and hydrochloric acids were evaluated for the efficiency of both methods. A certified reference material (CRM 146) was used in the comparison of these two digestion methods. The results revealed a good agreement between both procedures and the certified valued. The best recoveries were found in the range between 95% and 99% for microwave assisted digestion with a mixture of 2 ml of HF, 6 ml of HNO(3) and 2 ml of HCl. This procedure was recommended as the method for digestion the compost herein based on the recovery analysis and time taken.

Matched MeSH terms: Reference Standards
Multi-residue analytical method for human pharmaceuticals and synthetic hormones in river water and sewage effluents by solid-phase extraction and liquid chromatography-tandem mass spectrometry

Al-Odaini NA, Zakaria MP, Yaziz MI, Surif S

J Chromatogr A, 2010 Oct 29;1217(44):6791-806.
PMID: 20851398 DOI: 10.1016/j.chroma.2010.08.033

Pollutants such as human pharmaceuticals and synthetic hormones that are not covered by environmental legislation have increasingly become important emerging aquatic contaminants. This paper reports the development of a sensitive and selective multi-residue method for simultaneous determination and quantification of 23 pharmaceuticals and synthetic hormones from different therapeutic classes in water samples. Target pharmaceuticals include anti-diabetic, antihypertensive, hypolipidemic agents, β2-adrenergic receptor agonist, antihistamine, analgesic and sex hormones. The developed method is based on solid phase extraction (SPE) followed by instrumental analysis using liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) with 30 min total run time. River water samples (150 mL) and (sewage treatment plant) STP effluents (100 mL) adjusted to pH 2, were loaded into MCX (3 cm(3), 60 mg) cartridge and eluted with four different reagents for maximum recovery. Quantification was achieved by using eight isotopically labeled internal standards (I.S.) that effectively correct for losses during sample preparation and matrix effects during LC-ESI-MS/MS analysis. Good recoveries higher than 70% were obtained for most of target analytes in all matrices. Method detection limit (MDL) ranged from 0.2 to 281 ng/L. The developed method was applied to determine the levels of target analytes in various samples, including river water and STP effluents. Among the tested emerging pollutants, chlorothiazide was found at the highest level, with concentrations reaching up to 865 ng/L in STP effluent, and 182 ng/L in river water.

Matched MeSH terms: Reference Standards

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