1,732 research outputs found

    Use of mathematical derivatives (time-domain differentiation) on chromatographic data to enhance the detection and quantification of an unknown 'rider' peak

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    Two samples of an anticancer prodrug, AQ4N, were submitted for HPLC assay and showed an unidentified impurity that eluted as a 'rider' on the tail of the main peak. Mathematical derivatization of the chromatograms offered several advantages over conventional skimmed integration. A combination of the second derivative amplitude and simple linear regression gave a novel method for estimating the true peak area of the impurity peak. All the calculation steps were carried out using a widely available spreadsheet program. (C) 2003 Elsevier B.V. All rights reserved

    Coming Up Dirty: Drug Testing at the Work Place

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    Inkjet printing scalable dosage forms capable of increasing the solubility of BCS Class II drugs

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    Oral drug delivery remains the preferred method of administration but BCS Class II drugs are not ideally suited to this due to their inherent poor solubility. Although a number of methods to increase solubility already exist, there is a need for manufacturing methods which are more flexible to the requirements of the individual patient. The current work aims to increase the solubility of poorly soluble drugs using the innovative manufacturing technique of inkjet printing with a view to creating formulations which are more easily tailored to the needs of the patient. Ultimately it has been established that printing the BCS Class II drug alone results in a crystalline product but on addition of a polymer this crystallinity is reduced and it is possible to print solid dispersions which are fully amorphous. Printing has also allowed greater control over drug distribution, which has allowed improved solubility overall. Additionally, the printer has proved itself capable of producing scalable products with a view to more patient centric dosage form manufacture

    Manometric Temperature Measurement (MTM) lyophilisation of a challenging clinical trial pharmaceutical

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    INTRODUCTION Cancer Research UK Formulation Unit The Formulation Unit based at the University of Strathclyde in Glasgow has a research and development history in excess of 25 years, being funded by, and working in partnership with, firstly Cancer Research Campaign, and since 2002, with Cancer Research UK. The Unit is based in an entirely academic University setting, and since 2004 has been licensed by the UK government Medicines and Healthcare products Regulatory Agency (MHRA) for research, development and manufacture of Phase I/II novel small molecule cancer therapeutics and diagnostics. Research programs have delivered new formulations to clinical trial as either sterile or non-sterile presentations. However, the Unit’s specialty is based around small volume parenteral product manufacture. Boronophenylalanine (L-BPA) in Boron Neutron Capture Therapy (BNCT) L-BPA is the premier pharmaceutical selection in BNCT in treatment of selected head and neck tumours. BNCT relies on localisation of boron 10 within a tumour mass, made possible by the amino acid carrier portion of the L-BPA molecule. Phenylalanine is selectively transported across the blood brain barrier and then into astrocytic cells by a LAT-1 transporter system that is up-regulated in tumour. A targeted external neutron beam activates the accumulated L-BPA. In brief, neutron capture by boron causes nuclear re-arrangement and formation of a high linear energy transfer alpha particle and lithium 7 nuclei. Thus the patient is dosed with localised radiotherapy. OLD FORMULATION Issues existed with the previous standard formulation of L-BPA in fructose. L-BPA complexed with fructose has low solubility of around 30mg/mL. Consequently, large administration volumes are required to achieve clinical dosing in tens of grams of drug per patient. Moreover, L-BPA in fructose solutions must be freshly prepared and administered within 48 hours for reasons of product instability (Henriksson et al, 2008). Although rare, hereditary fructose intolerance needs to be considered. Taken together, L-BPA production, preparation and patient dosing is highly challenging. NEW FORMULATION Restrictions The Formulation Unit developed a new improved formulation; the drug product was a lyophilized pH8 solution of L-BPA at 100mg/mL in 110mg/mL mannitol (Schmidt et al, 2011). When lyophilised, a shelf life of 48 months was supported for the drug product. Whilst a three times increase in solubility, and a significantly enhanced product lifetime were worthy formulation enhancements, a new restriction emerged; the solution for lyophilisation contained 21% w/v solids far exceeding the ‘normal’ region of 2% w/v to 5% w/v (Boylan and Nail, 2009). Moreover, the lyophilisation cycle of 6 days was considered commercially unfavourable. A shortened drying cycle of 1 to 3 days would be preferred. Research was therefore initiated to reduce drying cycle time utilising Manometric Temperature Measurement (MTM) technology. MTM Studies MTM controlled freeze drying systems were originally marketed in the first decade of the new millennium. The ability to use software to calculate the performance at the freeze-drying front in real time is scientifically and commercially appealing. The possibility to optimize processing conditions at that same time as data is being received invites the prospect of a reduced experimentation phase thereby rapidly reaching the goal of a maximally efficient freeze drying cycle. In theory, even a minimally experienced operator could achieve this outcome. In summary, MTM functions by taking pressure rise information at regular intervals (Giesler et al, 2007). Based on SMART® software (SP Scientific, Stone Ridge, NY, USA), hourly pressure rise data are taken at a rate of 10 samples per second. The system calculates the product temperature at the sublimation interface and mass transfer resistance of the product. Adjustments are then automatically made to the shelf temperature and system pressure to achieve a calculated target product temperature. The end of primary drying can be determined by comparing the vapour pressure of ice with the system chamber pressure. Input data is minimal, such as vial number, inner vial area, fill volume and weight, concentration, product critical temperature. MATERIALS AND METHODS Chemicals Syntagon AB, Södertälje, Sweden manufactured BPA raw material according to EU current Good Manufacturing Practice (cGMP). D-mannitol (Ph. Eur) was sourced from Sigma-Aldrich, Poole, UK, and fuming hydrochloric acid and sodium hydroxide pellets (both extra pure Ph. Eur., BP, JP, NF) were obtained from VWR International, Lutterworth, UK. Water for Irrigation (WFI) in bulk was acquired from Baxter’s Healthcare Ltd., Norfolk, UK. Type 1 clear glass 50mL vials with 20mm butyl rubber stoppers (proved clean), crimped with 20mm tear off aluminium overseals were all from Adelphi Healthcare Packaging, Haywards Heath, UK. Lyophilisation equipment MTM software (SMART®) was operated on an FTS Systems Lyostar II drier (Biopharma, Winchester, UK). CONCLUSION A new improved L-BPA formulation in mannitol has been developed and used in human clinical trial. Further research using MTM technology succeeded in reducing a 6 day drug product drying cycle to 53 hours. The formulation exhibited non-ideal behaviour, and MTM failed to predict drying parameters, e.g., base of vial temperature, that are more closely replicated in ‘ideal’ test articles such as a 5% mannitol comparator. Further test lyophilisations are required to reach ideal. ACKNOWLEDGMENTS This research is funded by Cancer Research UK. REFERENCES 1. Boylan, J.C. and Nail, S.L. Parenteral Products, in: Florence, A.T. and Siepman, J. (Eds.), Modern Pharmaceutics. Informa Healthcare, New York, 565-609 (2009). 2. Giesler, H.; Kramer, T. and Pikal, M. J. Use of manometric temperature measurement (MTM) and SMART freeze dryer technology for development of an optimised freeze drying cycle. J. Pharm Sci. 96(12), 3402-3418 (2007). 3. Henriksson, R.; Capala, J.; Michanek, A.; Lindahl, S.A.; Satford, L.G.; Franzen, L.; Blomquist, E.; Westlin, J.E. and Bergenheim, A.T. Boron neutron capture therapy (BNCT) for glioblastoma multiforme: A phase II study evaluating a prolonged high-dose of boronophenylalanine (BPA). Radiotherapy and Oncology 88, 183-191 (2008). 4. Schmidt, E.; Dooley, N.; Ford, S. J.; Elliott, M. and Halbert, G. W. Physicochemical investigation of the influence of saccharide based parenteral formulation excipients on L-p-boronphenylalanine solubilisation for Boron Neutron Capture Therapy. J. Pharm. Sci. 101(1), 223-232 (2011)

    Achieving immediate release dosage forms using DoE and injection moulding

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    This study investigates a variety of disintegrating agents and small molecules to assess their suitability to increase the rate of the erosion process of Polyvinyl Alcohol (PVA)

    Occurrence of the Old World bug Megacopta cribraria (Fabricius) (Heteroptera: Plataspidae) in Georgia: a serious home invader and potential legume pest

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    Specimens of Megacopta cribraria (Fabricius) were collected in northern Georgia in late October 2009, where they were invading homes in large numbers. This is the first known occurrence of this species and the family Plataspidae in the New World. Megacopta cribraria was previously known from Asia and Australia. A key is provided to separate Plataspidae from other families of Pentatomoidea in America North of Mexico. A diagnosis and figures are provided to facilitate recognition of M. cribraria. Reported host plants and other aspects of the biology of this species are reviewed. Megacopta cribraria is considered a pest of numerous legumes in Asia, has the potential to provide biological control of kudzu, Pueraria montana var. lobata (Willd.) Ohwi, (Fabaceae) and likely will continue to be a household pest in the vicinity of kudzu fields as well as become a pest of North American legume crops

    An investigation into fused filament fabrication for pharmaceutical manufacturing

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    In a modern world, what is the best way to deliver medicines to the patient? Human beings are an extremely diverse species with many different factors that can influence the behaviour of a drug within the body. Children are a perfect example of such variety. Doses are often prescribed based on body weight, and can vary greatly from infants to adolescents. With current ‘traditional’ manufacture of oral dose pharmaceuticals, generally only a limited number of doses are produced, leading to difficulties with appropriate dosing. The ability to manufacture personalised doses for these patients would be of great benefit both practically and financially, and may even lead to ‘point of care’ manufacture

    Conserved microRNA editing in mammalian evolution, development and disease.

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    BACKGROUND: Mammalian microRNAs (miRNAs) are sometimes subject to adenosine-to-inosine RNA editing, which can lead to dramatic changes in miRNA target specificity or expression levels. However, although a few miRNAs are known to be edited at identical positions in human and mouse, the evolution of miRNA editing has not been investigated in detail. In this study, we identify conserved miRNA editing events in a range of mammalian and non-mammalian species. RESULTS: We demonstrate deep conservation of several site-specific miRNA editing events, including two that date back to the common ancestor of mammals and bony fishes some 450 million years ago. We also find evidence of a recent expansion of an edited miRNA family in placental mammals and show that editing of these miRNAs is associated with changes in target mRNA expression during primate development and aging. While global patterns of miRNA editing tend to be conserved across species, we observe substantial variation in editing frequencies depending on tissue, age and disease state: editing is more frequent in neural tissues compared to heart, kidney and testis; in older compared to younger individuals; and in samples from healthy tissues compared to tumors, which together suggests that miRNA editing might be associated with a reduced rate of cell proliferation. CONCLUSIONS: Our results show that site-specific miRNA editing is an evolutionarily conserved mechanism, which increases the functional diversity of mammalian miRNA transcriptomes. Furthermore, we find that although miRNA editing is rare compared to editing of long RNAs, miRNAs are greatly overrepresented among conserved editing targets

    Taking ethical photos of children for medical and research purposes in low-resource settings: an exploratory qualitative study.

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    Photographs are commonly taken of children in medical and research contexts. With the increased availability of photographs through the internet, it is increasingly important to consider their potential for negative consequences and the nature of any consent obtained. In this research we explore the issues around photography in low-resource settings, in particular concentrating on the challenges in gaining informed consent
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