Generic Samples » News http://www.genericsamples.com/wp Fri, 10 Sep 2010 02:36:30 +0000 http://wordpress.org/?v=2.8.5 en hourly 1 Comparison in purity and antitumor effect of brand and generic paclitaxel… http://www.genericsamples.com/wp/comparison-in-purity-and-antitumor-effect-of-brand-and-generic-paclitaxel/ http://www.genericsamples.com/wp/comparison-in-purity-and-antitumor-effect-of-brand-and-generic-paclitaxel/#comments Thu, 09 Sep 2010 06:46:18 +0000 jos http://www.genericsamples.com/wp/comparison-in-purity-and-antitumor-effect-of-brand-and-generic-paclitaxel/ Comparison in purity and antitumor effect of brand and generic paclitaxel against human ovarian cancer cells by an in vitro experimental model. Drug Dev Ind Pharm. 2010 Oct;36(10):1253-8 Authors: Wang KL, Yang YC, Cheng-Yen Lai J, Tsai TH, Lin CP, Wu YT, Chen YY, Wang SC, Chen YJ Context: The purity and the therapeutic effectiveness of the generic paclitaxel have not yet been examined and compared to the original brand form. Objective: This study aimed to compare the in vitro purity and biological effects of original brand form (Taxol) and a generic drug of paclitaxel. Materials and Methods: Purity was determined by high-performance liquid chromatography analysis, cell viability by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay, cell proliferation by clonogenic assay, morphology by Liu’s staining, and cell cycle distribution by DNA histogram. Results: Taxol and generic paclitaxel shared similar high-performance liquid chromatography profiles with a major peak at the same retention time and ultraviolet spectrum. Generic paclitaxel inhibited the cell viability to an extent greater than Taxol. By assessing the IC(50), generic paclitaxel also exhibited a greater inhibitory activity on clonogenicity of human ovarian adenocarcinoma SKOV-3 cells. Although both generic paclitaxel and Taxol arrested SKOV-3 and ES-2 cells at G2/M phase with concurrent development of hypoploid and polyploid cells, Taxol treatment exhibited markedly less extent of these changes. Observation of cellular morphology revealed a greater amount of mitotic catastrophe-like and apoptotic cells in generic paclitaxel-treated cells than Taxol-treated cells. Discussion and Conclusion: The results suggest that generic paclitaxel may possess a greater cell death inducing capacity and clonogenicity inhibitory activity against ovarian cancer cells than the original brand Taxol of the same purity. We conclude that this experimental model for assessing the difference between generic and brand name drugs might be considered as a reference while determining their interchangeability and could be easily established in a hospital-based laboratory. PMID: 20818963 [PubMed - in process]

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Comparison in purity and antitumor effect of brand and generic paclitaxel…

]]> http://www.genericsamples.com/wp/comparison-in-purity-and-antitumor-effect-of-brand-and-generic-paclitaxel/feed/ 0 An integrated phosphoproteomics work flow reveals extensive network… http://www.genericsamples.com/wp/an-integrated-phosphoproteomics-work-flow-reveals-extensive-network/ http://www.genericsamples.com/wp/an-integrated-phosphoproteomics-work-flow-reveals-extensive-network/#comments Mon, 06 Sep 2010 02:27:29 +0000 jos http://www.genericsamples.com/wp/an-integrated-phosphoproteomics-work-flow-reveals-extensive-network/ Related Articles An integrated phosphoproteomics work flow reveals extensive network regulation in early lysophosphatidic acid signaling. Mol Cell Proteomics. 2010 Jun;9(6):1047-62 Authors: Schreiber TB, Mäusbacher N, Kéri G, Cox J, Daub H Lysophosphatidic acid (LPA) induces a variety of cellular signaling pathways through the activation of its cognate G protein-coupled receptors. To investigate early LPA responses and assess the contribution of epidermal growth factor (EGF) receptor transactivation in LPA signaling, we performed phosphoproteomics analyses of both total cell lysate and protein kinase-enriched fractions as complementary strategies to monitor phosphorylation changes in A498 kidney carcinoma cells. Our integrated work flow enabled the identification and quantification of more than 5,300 phosphorylation sites of which 224 were consistently regulated by LPA. In addition to induced phosphorylation events, we also obtained evidence for early dephosphorylation reactions due to rapid phosphatase regulation upon LPA treatment. Phosphorylation changes induced by direct heparin-binding EGF-like growth factor-mediated EGF receptor activation were typically weaker and only detected on a subset of LPA-regulated sites, indicating signal integration among EGF receptor transactivation and other LPA-triggered pathways. Our results reveal rapid phosphoregulation of many proteins not yet implicated in G protein-coupled receptor signaling and point to various additional mechanisms by which LPA might regulate cell survival and migration as well as gene transcription on the molecular level. Moreover, our phosphoproteomics analysis of both total lysate and kinase-enriched fractions provided highly complementary parts of the LPA-regulated signaling network and thus represents a useful and generic strategy toward comprehensive signaling studies on a system-wide level. PMID: 20071362 [PubMed - indexed for MEDLINE]

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]]> http://www.genericsamples.com/wp/an-integrated-phosphoproteomics-work-flow-reveals-extensive-network/feed/ 0 Impact of Medicare Part D on independent and chain community pharmacies in… http://www.genericsamples.com/wp/impact-of-medicare-part-d-on-independent-and-chain-community-pharmacies-in/ http://www.genericsamples.com/wp/impact-of-medicare-part-d-on-independent-and-chain-community-pharmacies-in/#comments Sun, 05 Sep 2010 22:14:52 +0000 jos http://www.genericsamples.com/wp/impact-of-medicare-part-d-on-independent-and-chain-community-pharmacies-in/ Related Articles Impact of Medicare Part D on independent and chain community pharmacies in rural Illinois–A qualitative study. Res Social Adm Pharm. 2010 Jun;6(2):110-20 Authors: Bono JD, Crawford SY BACKGROUND: Although the sustainability of rural pharmacy services is a concern of long standing, the rural marketplace is not monolithic. Enhanced understanding of different experiences, strengths, and potential weaknesses of rural chain and independent pharmacies could help inform health policy debates, legislation, and consideration of disparities and access. This study compared and contrasted experiences by pharmacists in chain and independent community pharmacies during Medicare Part D implementation. OBJECTIVE: The objective was to obtain and describe experiential narratives from rural Illinois pharmacists regarding the implementation of Medicare Part D. Similarities and differences experienced in chain and independent community pharmacies were examined, as well as pharmacists’ perceptions about potential implications of the newly implemented Act on the accessibility of rural pharmacy care and services. METHODS: A semistructured qualitative research approach was used, involving focus groups and telephone interviews, to elicit the subjective experiences of rural Illinois pharmacists. Participants were selected through purposive sampling to include representative perspectives of independent and chain community pharmacists in rural areas across the state. Using a systematic, iterative coding process, recurrent themes were identified in 8 substantive categories. RESULTS: Areas of similarity between the 2 groups included universal criticism of the initial implementation processes, but consensus belief that Medicare patients ultimately benefited if they did not have previous prescription drug coverage. Pharmacists in independent drugstores expressed more concern about their future viability. Corporate communications and infrastructure support were available in chain pharmacies and believed to present them with competitive advantages and a stronger long-term financial position. CONCLUSIONS: The findings showed a disparate impact of Medicare Part D on the initial experiences and perceived viability of independent community pharmacies, in comparison with their chain pharmacy counterparts. The long-term implications of changing regulatory environments and customers’ pharmacy needs in underserved communities should be carefully considered and monitored. PMID: 20511110 [PubMed - indexed for MEDLINE]

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]]> http://www.genericsamples.com/wp/impact-of-medicare-part-d-on-independent-and-chain-community-pharmacies-in/feed/ 0 The Effect of Medication Samples on Self-Reported Prescribing Practices: A… http://www.genericsamples.com/wp/the-effect-of-medication-samples-on-self-reported-prescribing-practices-a/ http://www.genericsamples.com/wp/the-effect-of-medication-samples-on-self-reported-prescribing-practices-a/#comments Sun, 05 Sep 2010 15:21:34 +0000 jos http://www.genericsamples.com/wp/the-effect-of-medication-samples-on-self-reported-prescribing-practices-a/ Related Articles The Effect of Medication Samples on Self-Reported Prescribing Practices: A Statewide, Cross-Sectional Survey. J Gen Intern Med. 2010 Aug 31; Authors: Pinckney RG, Helminski AS, Kennedy AG, Maclean CD, Hurowitz L, Cote E BACKGROUND: The pharmaceutical industry spends billions of dollars annually to encourage clinicians to prescribe their medications. Small studies have demonstrated that one of the marketing strategies, the distribution of free sample medications, is associated with increased use of brand name medication over generic medication. OBJECTIVES: To determine the relationship between the presence of drug samples in primary care clinics and prescription of preferred drug treatments. DESIGN: Cross-sectional survey. PARTICIPANTS: Primary care prescribers in the state of Vermont. MAIN MEASUREMENT: Prescribers were presented with two clinical vignettes and asked to provide the name of the medication they would prescribe in each case. We compared the responses of prescribers with and without samples in their clinics. KEY RESULTS: Two hundred six prescribers out of the total population of 631 returned the survey and met the eligibility criteria. Seventy-two percent of prescribers had sample closets in their clinics. Seventy percent of clinicians with samples would prescribe a thiazide diuretic for hypertension compared to 91% in those without samples (P < 0.01). For managing depression 91% of prescribers with samples would have provided a generic medication in a patient with no health insurance, compared to 100% of those without samples in their clinic (P = 0.02). CONCLUSIONS: Clinicians with samples in their clinics were less likely to prescribe preferred medications for hypertension and depression. PMID: 20809157 [PubMed - as supplied by publisher]

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]]> http://www.genericsamples.com/wp/the-effect-of-medication-samples-on-self-reported-prescribing-practices-a/feed/ 0 Saving lives, money and resources: drug and CABG/PCI use after myocardial… http://www.genericsamples.com/wp/saving-lives-money-and-resources-drug-and-cabgpci-use-after-myocardial/ http://www.genericsamples.com/wp/saving-lives-money-and-resources-drug-and-cabgpci-use-after-myocardial/#comments Thu, 02 Sep 2010 09:17:02 +0000 jos http://www.genericsamples.com/wp/saving-lives-money-and-resources-drug-and-cabgpci-use-after-myocardial/ Related Articles Saving lives, money and resources: drug and CABG/PCI use after myocardial infarction in a Swedish record-linkage study. Eur J Health Econ. 2010 Apr;11(2):177-84 Authors: Wilhelmsen L, Welin L, Odén A, Björnberg A BACKGROUND: Drug costs are increasing despite the introduction of cheaper generic drugs. The aim of the present study was to analyse the entire costs of hospital care, out-patient care, and the cost of drugs for 16 months following a myocardial infarction (MI) to see to what extent drug costs contribute to the overall costs of care. METHODS: Diagnoses and costs for care as well as mortality data obtained from the Västra Götaland Region, Sweden, and drug costs from the Swedish Board of Health and Welfare, were merged in a computer file. Patients registered from 1 July 2005 to 30 June 2006 were followed from 28 days after an MI, with follow-up until 31 October 2006. RESULTS: Of 4,725 patients, 711 died before the start of the study and 721 during follow-up. Higher age [hazard ratio (HR, 95%CI) = 1.06 (1.05-1.07)], previous MI [HR = 1.31 (1.13-1.53)] and diabetes mellitus [HR = 1.34 (1.13-1.58)] were associated with increased mortality, which decreased with coronary interventions: CABG/PCI [HR = 0.19 (0.14-0.27)]. In a multivariable analysis, mortality was lower for patients taking simvastatin [HR = 0.62 (0.50-0.76)] and clopidogrel [HR = 0.58 (0.46-0.74)]. CONCLUSION: Costs for out-patient care accounted for 25% and drugs for 5% of total costs. If patients not treated with simvastatin or clopidogrel had received these drugs, an additional 154-306 lives might have been saved. Drug costs would be higher, but total costs lower. Thus, even expensive drugs may reduce overall costs. PMID: 19495819 [PubMed - indexed for MEDLINE]

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]]> http://www.genericsamples.com/wp/saving-lives-money-and-resources-drug-and-cabgpci-use-after-myocardial/feed/ 0 A generic static headspace gas chromatography method for determination of… http://www.genericsamples.com/wp/a-generic-static-headspace-gas-chromatography-method-for-determination-of/ http://www.genericsamples.com/wp/a-generic-static-headspace-gas-chromatography-method-for-determination-of/#comments Wed, 01 Sep 2010 20:14:17 +0000 admin http://www.genericsamples.com/wp/a-generic-static-headspace-gas-chromatography-method-for-determination-of/ Related Articles A generic static headspace gas chromatography method for determination of residual solvents in drug substance. J Chromatogr A. 2010 Aug 13; Authors: Cheng C, Liu S, Mueller BJ, Yan Z In order to increase productivity of drug analysis in the pharmaceutical industry, an efficient and sensitive generic static headspace gas chromatography (HSGC) method was successfully developed and validated for the determination of 44 classes 2 and 3 solvents of International Conference of Harmonization (ICH) guideline Q3C, as residual solvents in drug substance. In order to increase the method sensitivity and efficiency in sample equilibration, dimethylsulfoxide (DMSO) was selected as the sample diluent based on its high capacity of dissolving drug substance, stability and high boiling point. The HS sample equilibration temperature and equilibration time are assessed in ranges of 125-150 degrees C and 8-15min, respectively. The results indicate that the residual solvents in 200mg of drug substance can be equilibrated efficiently in HS sampler at 140 degrees C for 10min. The GC parameters, e.g. sample split ratio, carrier flow rate and oven temperature gradient are manipulated to enhance the method sensitivity and separation efficiency. The two-stage gradient GC run from 35 to 240 degrees C, using an Agilent DB-624 capillary column (30m long, 0.32mm I.D., 1.8mum film thickness), is suitable to determine 44 ICH classes 2 and 3 solvents in 30min. The method validation results indicate that the method is accurate, precise, linear and sensitive for solvents assessed. The recoveries of most of these solvents from four drug substances are greater than 80% within the method determination ranges. However, this method is not suitable for the 10 remaining ICH classes 2 and 3 solvents, because they are too polar (e.g. formic acid and acidic acid), or have boiling points higher than 150 degrees C, (e.g. anisol and cumene). In comparison with the previous published methods, this method has a much shorter sample equilibration time, a better separation for many solvents, a higher sensitivity and a broader concentration range. PMID: 20801455 [PubMed - as supplied by publisher]

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]]> http://www.genericsamples.com/wp/a-generic-static-headspace-gas-chromatography-method-for-determination-of/feed/ 0 Cardiovascular and Economic Outcomes After Initiation of Atorvastatin… http://www.genericsamples.com/wp/cardiovascular-and-economic-outcomes-after-initiation-of-atorvastatin/ http://www.genericsamples.com/wp/cardiovascular-and-economic-outcomes-after-initiation-of-atorvastatin/#comments Wed, 01 Sep 2010 16:43:42 +0000 admin http://www.genericsamples.com/wp/cardiovascular-and-economic-outcomes-after-initiation-of-atorvastatin/ Related Articles Cardiovascular and Economic Outcomes After Initiation of Atorvastatin versus Simvastatin in an Employed Population Stratified by Cardiovascular Risk. Am J Ther. 2010 Aug 27; Authors: Simpson RJ, Signorovitch J, Ramakrishnan K, Ivanova J, Birnbaum H, Kuznik A The relative effects of atorvastatin and simvastatin among higher- and lower-risk patients are not well characterized. This study compared cardiovascular (CV) risk and direct and indirect costs among higher- and lower-risk employees initiating atorvastatin vs. simvastatin. Using a large employer claims database (1999-2006), employees were stratified as 1) high-risk employees with prior CV events, diabetes, or renal disorders; and 2) low- to intermediate-risk employees without these conditions. Propensity score matching was used, and 2-year outcomes were compared between matched cohorts. Indirect costs included disability payments and medically related absenteeism. Drug costs were imputed with recent prices to account for availability of generic simvastatin. Among 4167 matched pairs of high-risk employees, atorvastatin use was associated with a numerically lower risk of CV events (17.6 versus 18.4%, P = 0.37), higher direct medical costs ($17,590 versus $17,377, P = 0.002), numerically lower indirect costs ($4830 versus $4989, P = 0.29), and higher total costs by $54 ($22,420 versus $22,366, P = 0.034). The majority of high-risk employees (62%) received low initial statin doses (atorvastatin = 10 mg or simvastatin = 20 mg). Among 9326 matched pairs of low- to intermediate-risk employees, atorvastatin use was associated with a lower risk of CV events (3.1% versus 3.7%, P = 0.030), lower direct medical costs ($8400 versus $8436, P < 0.001), numerically lower indirect costs ($2781 versus $2807; P = 0.12), and lower total costs by $61 ($11,181 versus $11,243, P < 0.001). These results suggest that formulary policies reserving atorvastatin for higher-risk patients may not be cost-saving from the employer perspective. PMID: 20802306 [PubMed - as supplied by publisher]

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Cardiovascular and Economic Outcomes After Initiation of Atorvastatin…

]]> http://www.genericsamples.com/wp/cardiovascular-and-economic-outcomes-after-initiation-of-atorvastatin/feed/ 0 The mitochondrial ribosomal protein of the large subunit, Afo1p, determines… http://www.genericsamples.com/wp/the-mitochondrial-ribosomal-protein-of-the-large-subunit-afo1p-determines/ http://www.genericsamples.com/wp/the-mitochondrial-ribosomal-protein-of-the-large-subunit-afo1p-determines/#comments Fri, 27 Aug 2010 18:46:14 +0000 jos http://www.genericsamples.com/wp/the-mitochondrial-ribosomal-protein-of-the-large-subunit-afo1p-determines/ Related Articles The mitochondrial ribosomal protein of the large subunit, Afo1p, determines cellular longevity through mitochondrial back-signaling via TOR1. Aging (Albany NY). 2009 Jul;1(7):622-36 Authors: Heeren G, Rinnerthaler M, Laun P, von Seyerl P, Kössler S, Klinger H, Hager M, Bogengruber E, Jarolim S, Simon-Nobbe B, Schüller C, Carmona-Gutierrez D, Breitenbach-Koller L, Mück C, Jansen-Dürr P, Criollo A, Kroemer G, Madeo F, Breitenbach M Yeast mother cell-specific aging constitutes a model of replicative aging as it occurs in stem cell populations of higher eukaryotes. Here, we present a new long-lived yeast deletion mutation,afo1 (for aging factor one), that confers a 60% increase in replicative lifespan. AFO1/MRPL25 codes for a protein that is contained in the large subunit of the mitochondrial ribosome. Double mutant experiments indicate that the longevity-increasing action of the afo1 mutation is independent of mitochondrial translation, yet involves the cytoplasmic Tor1p as well as the growth-controlling transcription factor Sfp1p. In their final cell cycle, the long-lived mutant cells do show the phenotypes of yeast apoptosis indicating that the longevity of the mutant is not caused by an inability to undergo programmed cell death. Furthermore, the afo1 mutation displays high resistance against oxidants. Despite the respiratory deficiency the mutant has paradoxical increase in growth rate compared to generic petite mutants. A comparison of the single and double mutant strains for afo1 and fob1 shows that the longevity phenotype of afo1 is independent of the formation of ERCs (ribosomal DNA minicircles). AFO1/MRPL25 function establishes a new connection between mitochondria, metabolism and aging. PMID: 20157544 [PubMed - indexed for MEDLINE]

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The mitochondrial ribosomal protein of the large subunit, Afo1p, determines…

]]> http://www.genericsamples.com/wp/the-mitochondrial-ribosomal-protein-of-the-large-subunit-afo1p-determines/feed/ 0 Statins: Cost analysis in Indian scenario from eight major clinical trials. http://www.genericsamples.com/wp/statins-cost-analysis-in-indian-scenario-from-eight-major-clinical-trials/ http://www.genericsamples.com/wp/statins-cost-analysis-in-indian-scenario-from-eight-major-clinical-trials/#comments Fri, 27 Aug 2010 12:11:39 +0000 jos http://www.genericsamples.com/wp/statins-cost-analysis-in-indian-scenario-from-eight-major-clinical-trials/ 65 was derived. CER for branded and generic versions was calculated by using the prices of statins listed in Indian Drug Review Triple i. Results: Cost-effectiveness ratio (CER) in primary prevention studies i.e., the WOSCOPS, the AFCAPS and the ASCOT-LLA was Rs. 25.8 lacs, Rs. 23.8 lacs and Rs. 7.9 lacs per major coronary event averted respectively. CER in secondary prevention studies i.e., the CARE and the LIPID was approximately Rs. 20 lacs per major coronary event averted while it was Rs. 52.4 lacs and Rs. 37 lacs per coronary heart disease (CHD) death avoided. CER from the 4S was Rs. 6.9 lacs per major coronary event and Rs. 16.9 lacs per CHD death averted. CER in the HPS and the PROSPER study was Rs. 17.9 lacs and Rs. 27.1 lacs per major coronary event avoided in high-risk patients. Conclusion: Cost associated with the use of statins is higher in primary prevention as compared to secondary prevention. More studies are needed to confirm the cost-effectiveness of statins to make any decision for health policy. PMID: 20739765 [PubMed - in process] ]]> Statins: Cost analysis in Indian scenario from eight major clinical trials. J Postgrad Med. 2010 Jul-Sep;56(3):196-200 Authors: Sanmukhani J, Shah V Background and Aims: Coronary heart disease (CHD) is the leading cause of death in India resulting in loss of young Indians. Statins have proved to reduce the CHD mortality in various clinical trials. The aim of the study is to find the cost-effectiveness ratio (CER) for each major coronary event averted and a coronary death avoided by use of statins in different clinical settings based on the data from the major clinical trials on statins. Materials and Methods: Using electronic database and as per our inclusion and exclusion criteria we selected the West of Scotland Coronary Prevention Study (WOSCOPS), the Air Force Coronary Atherosclerosis Prevention Study (AFCAPS) and the Anglo-Scandinavian Cardiac Outcomes Trial–Lipid Lowering Arm (ASCOT-LLA) study for primary prevention; the Cholesterol and Recurrent Events Trial (CARE), the Long-term Intervention with Pravastatin in Ischemic Disease (LIPID) Study and the Scandinavian Simvastatin Survival Study (4S) for secondary prevention and two studies, the Heart Protection Study (HPS) and the Pravastatin in elderly individuals at risk of vascular disease (PROSPER) study for high-risk patients. The results of these studies were used for cost-effectiveness analysis of statins in different patient groups. Statistical Analysis: Absolute risk reduction, Number Needed to Benefit (NNTB), NNTB/year for total sample and in subgroups of males, females and age > 65 was derived. CER for branded and generic versions was calculated by using the prices of statins listed in Indian Drug Review Triple i. Results: Cost-effectiveness ratio (CER) in primary prevention studies i.e., the WOSCOPS, the AFCAPS and the ASCOT-LLA was Rs. 25.8 lacs, Rs. 23.8 lacs and Rs. 7.9 lacs per major coronary event averted respectively. CER in secondary prevention studies i.e., the CARE and the LIPID was approximately Rs. 20 lacs per major coronary event averted while it was Rs. 52.4 lacs and Rs. 37 lacs per coronary heart disease (CHD) death avoided. CER from the 4S was Rs. 6.9 lacs per major coronary event and Rs. 16.9 lacs per CHD death averted. CER in the HPS and the PROSPER study was Rs. 17.9 lacs and Rs. 27.1 lacs per major coronary event avoided in high-risk patients. Conclusion: Cost associated with the use of statins is higher in primary prevention as compared to secondary prevention. More studies are needed to confirm the cost-effectiveness of statins to make any decision for health policy. PMID: 20739765 [PubMed - in process]

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Statins: Cost analysis in Indian scenario from eight major clinical trials.

]]> http://www.genericsamples.com/wp/statins-cost-analysis-in-indian-scenario-from-eight-major-clinical-trials/feed/ 0 Large-scale systematic analysis of 2D fingerprint methods and parameters to… http://www.genericsamples.com/wp/large-scale-systematic-analysis-of-2d-fingerprint-methods-and-parameters-to/ http://www.genericsamples.com/wp/large-scale-systematic-analysis-of-2d-fingerprint-methods-and-parameters-to/#comments Fri, 27 Aug 2010 08:48:47 +0000 jos http://www.genericsamples.com/wp/large-scale-systematic-analysis-of-2d-fingerprint-methods-and-parameters-to/ Related Articles Large-scale systematic analysis of 2D fingerprint methods and parameters to improve virtual screening enrichments. J Chem Inf Model. 2010 May 24;50(5):771-84 Authors: Sastry M, Lowrie JF, Dixon SL, Sherman W A systematic virtual screening study on 11 pharmaceutically relevant targets has been conducted to investigate the interrelation between 8 two-dimensional (2D) fingerprinting methods, 13 atom-typing schemes, 13 bit scaling rules, and 12 similarity metrics using the new cheminformatics package Canvas. In total, 157 872 virtual screens were performed to assess the ability of each combination of parameters to identify actives in a database screen. In general, fingerprint methods, such as MOLPRINT2D, Radial, and Dendritic that encode information about local environment beyond simple linear paths outperformed other fingerprint methods. Atom-typing schemes with more specific information, such as Daylight, Mol2, and Carhart were generally superior to more generic atom-typing schemes. Enrichment factors across all targets were improved considerably with the best settings, although no single set of parameters performed optimally on all targets. The size of the addressable bit space for the fingerprints was also explored, and it was found to have a substantial impact on enrichments. Small bit spaces, such as 1024, resulted in many collisions and in a significant degradation in enrichments compared to larger bit spaces that avoid collisions. PMID: 20450209 [PubMed - indexed for MEDLINE]

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