64 research outputs found

    STUDIES OF EFFECTS OF GSM-900 MICROWAVE EXPOSURE ON DNA ”MICRONUCLEUS” FORMATION IN MICE

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    Possible genotoxic effects of microwave exposure from GSM-900 mobile telephones have investigated with in vivo micronucleus assay of mouse erythrocytes from CBA mice and GFAP knockout mice. No significant change in the frequency of erythrocytes with micronuclei neither in the young (polychromatic PCE) or mature (normichromatic NCE) erythrocytes. There is, however, a tendency but not significant to increased MPCE in female mice after 35 days of exposure. There is a marked tendency to lower PCE-fraction in the exposed groups. When male and female is studied separately there is no significant difference. However, if the values are normalised to eliminate the sex-difference there is a significant lower fraction in the exposed mice. Another observation is lower weight of the exposed male. If normalised data for both sexes are pooled there is an almost significant difference (95% level) in weight. We found a less pronounced difference in the CBE mice than in the GFAP experiment. Thus genotype might play a role in microwave exposure. Differences in exposure time and number of controls in GFAP and CBA experiment might influence the results. We observe a moderate decrease of formation of new erythrocytes in the exposed animals. This might fit the tendency of lower weight in the exposed animals and might indicate a general decreased cell-proliferation in the exposed animals

    Meeting report: International workshop on implementation of biowaivers based on the biopharmaceutics classification system (BCS)

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    Even though the pivotal article stating the theoretical basis for a biopharmaceutics drug classification (1) was published almost 20 years ago, the extension of BCS-based biowaiver decisions to drugs belonging to BCS classes other than those showing high solubility and high permeability has not yet reached a consensus among regulators, industrial scientists, and academics. Also, within some jurisdictions, BCS principles have not yet been incorporated into legal frameworks and thus have not been used to allow science- and risk-based regulatory flexibility. This report provides a brief description of the presentations from the International Workshop on Implementation of Biowaivers based on the BCS in Buenos Aires, Argentina, that took place on March 5–6, 2015. The meeting was cosponsored by National University of La Plata, Confederación Farmacéutica Argentina, International Pharmaceutical Federation (FIP), and the American Association of Pharmaceutical Scientists (AAPS). The main objectives of the meeting were to describe the state of the art with respect to in vitro and in silico tools to support waiving in vivo bioequivalence studies and to foster discussion about implementing BCS-based biowaiver decisions to support generic drug registration in South America. Two hundred and fifteen scientists from universities, the pharmaceutical industry, and regulatory authorities took part in this meetingFacultad de Ciencias Exacta

    Meeting report: International workshop on implementation of biowaivers based on the biopharmaceutics classification system (BCS)

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    Even though the pivotal article stating the theoretical basis for a biopharmaceutics drug classification (1) was published almost 20 years ago, the extension of BCS-based biowaiver decisions to drugs belonging to BCS classes other than those showing high solubility and high permeability has not yet reached a consensus among regulators, industrial scientists, and academics. Also, within some jurisdictions, BCS principles have not yet been incorporated into legal frameworks and thus have not been used to allow science- and risk-based regulatory flexibility. This report provides a brief description of the presentations from the International Workshop on Implementation of Biowaivers based on the BCS in Buenos Aires, Argentina, that took place on March 5–6, 2015. The meeting was cosponsored by National University of La Plata, Confederación Farmacéutica Argentina, International Pharmaceutical Federation (FIP), and the American Association of Pharmaceutical Scientists (AAPS). The main objectives of the meeting were to describe the state of the art with respect to in vitro and in silico tools to support waiving in vivo bioequivalence studies and to foster discussion about implementing BCS-based biowaiver decisions to support generic drug registration in South America. Two hundred and fifteen scientists from universities, the pharmaceutical industry, and regulatory authorities took part in this meetingFacultad de Ciencias Exacta

    Current challenges and future perspectives in oral absorption research: An opinion of the UNGAP network

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    Although oral drug delivery is the preferred administration route and has been used for centuries, modern drug discovery and development pipelines challenge conventional formulation approaches and highlight the insufficient mechanistic understanding of processes critical to oral drug absorption. This review presents the opinion of UNGAP scientists on four key themes across the oral absorption landscape: (1) specific patient populations, (2) regional differences in the gastrointestinal tract, (3) advanced formulations and (4) food-drug interactions. The differences of oral absorption in pediatric and geriatric populations, the specific issues in colonic absorption, the formulation approaches for poorly water-soluble (small molecules) and poorly permeable (peptides, RNA etc.) drugs, as well as the vast realm of food effects, are some of the topics discussed in detail. The identified controversies and gaps in the current understanding of gastrointestinal absorption-related processes are used to create a roadmap for the future of oral drug absorption research.European Cooperation in Science and Technology CA16205National Centre for Research and Development POIR.01.02.00-00-0011/17Ministry of Education, Youth and Sports of the Czech Republic TC19039, LTC18003Czech Science Foundation 18-00132

    Meeting report: International workshop on implementation of biowaivers based on the biopharmaceutics classification system (BCS)

    Get PDF
    Even though the pivotal article stating the theoretical basis for a biopharmaceutics drug classification (1) was published almost 20 years ago, the extension of BCS-based biowaiver decisions to drugs belonging to BCS classes other than those showing high solubility and high permeability has not yet reached a consensus among regulators, industrial scientists, and academics. Also, within some jurisdictions, BCS principles have not yet been incorporated into legal frameworks and thus have not been used to allow science- and risk-based regulatory flexibility. This report provides a brief description of the presentations from the International Workshop on Implementation of Biowaivers based on the BCS in Buenos Aires, Argentina, that took place on March 5–6, 2015. The meeting was cosponsored by National University of La Plata, Confederación Farmacéutica Argentina, International Pharmaceutical Federation (FIP), and the American Association of Pharmaceutical Scientists (AAPS). The main objectives of the meeting were to describe the state of the art with respect to in vitro and in silico tools to support waiving in vivo bioequivalence studies and to foster discussion about implementing BCS-based biowaiver decisions to support generic drug registration in South America. Two hundred and fifteen scientists from universities, the pharmaceutical industry, and regulatory authorities took part in this meetingFacultad de Ciencias Exacta

    Nanofibrous scaffolds support a 3D in vitro permeability model of the human intestinal epitheleum

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    Advances in drug research not only depend on high throughput screening to evaluate large numbers of lead compounds but also on the development of in vitro models which can simulate human tissues in terms of drug permeability and functions. Potential failures, such as poor permeability or interaction with efflux drug transporters, can be identified in epithelial Caco-2 monolayer models and can impact a drug candidate’s progression onto the next stages of the drug development process. Whilst monolayer models demonstrate reasonably good prediction of in vivo permeability for some compounds, more developed in vitro tools are needed to assess new entities that enable closer in vivo in vitro correlation. In this study, an in vitro model of the human intestinal epithelium was developed by utilizing nanofibers, fabricated using electrospinning, to mimic the structure of the basement membrane. We assessed Caco-2 cell response to these materials and investigated the physiological properties of these cells cultured on the fibrous supports, focusing on barrier integrity and drug-permeability properties. The obtained data illustrate that 2D Caco-2 Transwell® cultures exhibit artificially high trans-epithelial electrical resistance (TEER) compared to cells cultured on the 3D nanofibrous scaffolds which show TEER values similar to ex vivo porcine tissue (also measured in this study). Furthermore, our results demonstrate that the 3D nanofibrous scaffolds influence the barrier integrity of the Caco-2 monolayer to confer drug-absorption properties that more closely mimic native gut tissue particularly for studying passive epithelial transport. We propose that this 3D model is a suitable in vitro model for investigating drug absorption and intestinal metabolism

    Clinical Relevance of Dissolution Testing in Quality by Design

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    Quality by design (QbD) has recently been introduced in pharmaceutical product development in a regulatory context and the process of implementing such concepts in the drug approval process is presently on-going. This has the potential to allow for a more flexible regulatory approach based on understanding and optimisation of how design of a product and its manufacturing process may affect product quality. Thus, adding restrictions to manufacturing beyond what can be motivated by clinical quality brings no benefits but only additional costs. This leads to a challenge for biopharmaceutical scientists to link clinical product performance to critical manufacturing attributes. In vitro dissolution testing is clearly a key tool for this purpose and the present bioequivalence guidelines and biopharmaceutical classification system (BCS) provides a platform for regulatory applications of in vitro dissolution as a marker for consistency in clinical outcomes. However, the application of these concepts might need to be further developed in the context of QbD to take advantage of the higher level of understanding that is implied and displayed in regulatory documentation utilising QbD concepts. Aspects that should be considered include identification of rate limiting steps in the absorption process that can be linked to pharmacokinetic variables and used for prediction of bioavailability variables, in vivo relevance of in vitro dissolution test conditions and performance/interpretation of specific bioavailability studies on critical formulation/process variables. This article will give some examples and suggestions how clinical relevance of dissolution testing can be achieved in the context of QbD derived from a specific case study for a BCS II compound
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