Generic Samples

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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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…