Effect of incomplete removal of the tert-butoxycarbonyl protecting group during synthesis of a pharmaceutical drug substance on the residual solvent analysis.

During development of the residual solvent method using headspace-GC for a drug substance, an unexpected peak was observed in the chromatography. GC-MS analysis confirmed the unknown peak identity as isobutylene. An understanding of the source of the isobutylene was required in order to develop appropriate impurity and residual solvent control strategies for the drug substance. The experiments performed to determine the source of the isobutylene peak observed in the headspace-GC chromatography and how the tert-butoxycarbonyl (BOC) de-protection step used in the drug substance synthesis contributes to its observation are discussed.

Lengsin expression and function during zebrafish lens formation.

A zebrafish ortholog of human lengsin was identified by EST analysis of an adult lens cDNA library. During zebrafish development, lengsin transcription is first detected at 24 h post-fertilization (hpf). Immunolocalization, using polyclonal antiserum generated against a Lengsin bacterial fusion protein, detects lens-specific protein in whole-mount embryos at 30 hpf. Lengsin expression in zebrafish follows the temporal expression of the alphaA- alphaB1- and betaB1-crystallin proteins in the lens. At 72 hpf, Lengsin is localized to a subpopulation of differentiating secondary fiber cells, while no expression is detected in the lens epithelial cells or central lens fibers. In the adult lens, Lengsin is restricted to a narrow band of cortical fibers and co-localizes with actin at the lateral faces of these interdigitating cells. Stable transgenic lines, using a 3 kb lengsin genomic fragment to regulate EGFP expression, recapitulate the Lengsin temporal and spatial expression patterns. Lengsin function in zebrafish lens formation was examined by antisense morpholino-mediated translation and mRNA splice inhibition. At 72 hpf, the lengsin morphant lenses are reduced in size and exhibit separations within the cortex due to defects in secondary fiber morphogenesis. The location of the morphant lens defects correlates with the Lengsin protein localization at this age. These results demonstrate Lengsin is required for proper fiber cell differentiation by playing roles in either cell elongation or the establishment of cell interactions.

Quantitation of acetol in common pharmaceutical excipients using LC-MS.

A method for the quantification of acetol at mug/L levels in propylene glycol and glycerol, two common pharmaceutical excipients, was developed and validated. This simple yet highly specific method makes use of derivatization by O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBHA) in aqueous solution at room temperature followed by analysis via LC-MS without sample pre-concentration, extraction, or cleanup. Kinetic studies indicated that the derivatization reaction was complete after 4.5h. Preliminary investigations demonstrate the applicability of this method to the separation and identification of other electrophilic impurities. This suggests the potential for a simple, quantitative assay at room temperature in aqueous solution for the determination of a variety of electrophilic impurities in pharmaceutical excipients, without the need for sample concentration or extraction.

National campaigns to improve antibiotic use.

High levels of antibiotic consumption are driving levels of bacterial resistance that threaten public health. Nonetheless, antibiotics still provide highly effective treatments for common diseases with important implications for human health. The challenge for public education is to achieve a meaningful reduction in unnecessary antibiotic use without adversely affecting the management of bacterial infections. This paper focuses on the lessons learned from national campaigns in countries (Belgium and France) with high antibiotic use. Evaluation of these national campaigns showed the importance of television advertising as a powerful medium to change attitudes and perhaps also behaviour with regard to antibiotics. Moreover, in both countries, strong evidence suggested reduced antibiotic prescribing. However, adverse effects associated with a reduction in antibiotic prescribing were not monitored. We conclude that carefully designed mass education campaigns could improve antibiotic use nationally and should be considered in countries with high antibiotic use. However, these campaigns should employ techniques of social marketing and use appropriate outcome measures. The benefits and risks of such campaigns have been less well established in countries where antibiotic use is already low or declining.

Educational interventions to improve antibiotic use in the community: report from the International Forum on Antibiotic Resistance (IFAR) colloquium, 2002.

National and international strategies for the control of antibiotic resistance recommend education for health-care professionals and the public to promote prudent antibiotic use. This paper, based on discussions at the 2002 colloquium of the International Forum on Antibiotic Resistance (IFAR), provides an international discourse between theoretical approaches to behaviour change and practical experience gained in large-scale antibiotic use educational campaigns. Interventions are more likely to be effective if their aim is to change behaviour, rather than provide information. They should target all relevant groups, especially parents, children, day-care staff, and health-care professionals. They should use clear and consistent messages concerning bacterial versus viral infection, prudent antibiotic use, symptomatic treatment, and infection-control measures (eg, handwashing). Campaigns should use a range of communications using pilot-testing, strong branding, and sociocultural adaptation. Prime-time television is likely to be the most effective public medium, while academic detailing is especially useful for health-care professionals. Multifaceted interventions can improve antibiotic prescribing to some degree. However, there are few data on their effects on resistance patterns and patient outcomes, and on their cost-effectiveness. Current research aims include the application of behaviour-change models, the development and validation of prudent antibiotic prescribing standards, and the refinement of tools to assess educational interventions.