Large-scale purification of factor VIII by affinity chromatography: optimization of process parameters

The optimization of a new process for the extraction of human coagulation factor VIII (FVIII) from plasma with the tailor-made affinity matrix dimethylaminopropylcarbamylpentyl-Sepharose CL-4B (C3---C5 matrix) is described. First, plasma is applied to DEAE-Sephadex A-50 anion exchanger in order to separate a number of proteins, including coagulation factors II, IX and X (prothrombin complex), from FVIII. Subsequently, the unbound fraction of the ion exchanger, containing FVIII, is contacted with the C3---C5 affinity matrix. Optimization of the FVIII affinity chromatographic procedure is accomplished in terms of the ligand density of the matrix, adsorption mode (batch-wise versus column-wise adsorption and matrix to plasma ratio), and conditions of pH and conductivity to be applied on washing and desorption. In scale-up experiments, by processing 20 1 of plasma, the recovery (340 U VIII:C/kg plasma) and the specific activity (s.a.) (1.2 U VIII:C/mg protein) are better than those obtained by cryoprecipitation (recovery 300 U VIII:C/kg plasma, s.a. O.3 U VIII:C/mg protein). The newly developed process using the specially designed C3---C5 affinity matrix has potential application in the process-scale purification of FVIII

An Industrial View on Enzymes for the Cleavage of Cephalosporin C

The enzymatic cleavage of cephalosporin C (CephC) into 7-aminocephalosporanic acid (7-ACA) and deacetyl-7-aminocephalosporanic acid (HACA), both key intermediates for cephalosporin antibiotics, has now been commercialized on an industrial scale. This article illustrates economic, technical, and regulatory aspects of the process, with special focus on the enzymes involved.Due to the compensation for low operational stability by low costs of preparation, cell immobilization of Trigonopsis variabilis seems an economically attractive and technically feasible way to prepare D-amino acid oxidase (EC 1.4.3.3). However, the application of immobilized cells is restricted to large-volume products, since it involves extensive development and characterization work. For glutaryl-7-ACA acylase (EC 3.5.1.3), expressed in Escherichia coli, isolation and immobilization of the enzyme on a commercial carrier seems more attractive from a regulatory point of view. The immobilized enzyme shows very high operational stability, which may compensate for the costs of the carrier. Despite its lower stability, cephalosporin G acetylesterase (EC 3.1.1.41), expressed in E. coli, was also immobilized on a commercial carrier for regulatory reasons. Moreover, extensive development of immobilized whole cells seemed economically not acceptable for this low-volume product. A mathematical model for the enzymatic cleavage showed limitations of a combined application of two biocatalysts in a stirred tank reactor, e.g., in terms of product yield

Concordance of the ForenSeq™ system and characterisation of sequence-specific autosomal STR alleles across two major population groups

By using sequencing technology to genotype loci of forensic interest it is possible to simultaneously target autosomal, X and Y STRs as well as identity, ancestry and phenotypic informative SNPs, resulting in a breadth of data obtained from a single run that is considerable when compared to that generated with standard technologies. It is important however that this information aligns with the genotype data currently obtained using commercially available kits for CE-based investigations such that results are compatible with existing databases and hence can be of use to the forensic community. In this work, 400 samples were typed using commercially available STR kits and CE, as well as using the Ilumina ForenSeq™ DNA Signature Prep Kit and MiSeq® FGx to assess concordance of autosomal STRs and population variability. Results show a concordance rate between the two technologies exceeding 99.98% while numerous novel sequence based alleles are described. In order to make use of the sequence variation observed, sequence specific allele frequencies were generated for White British and British Chinese populations

Impact of gastrointestinal tract variability on oral drug absorption and pharmacokinetics : an UNGAP review

The absorption of oral drugs is frequently plagued by significant variability with potentially serious therapeutic consequences. The source of variability can be traced back to interindividual variability in physiology, differences in special populations (age- and disease-dependent), drug and formulation properties, or food-drug interactions. Clinical evidence for the impact of some of these factors on drug pharmacokinetic variability is mounting: e.g. gastric pH and emptying time, small intestinal fluid properties, differences in pediatrics and the elderly, and surgical changes in gastrointestinal anatomy. However, the link of colonic factors variability (transit time, fluid composition, microbiome), sex differences (male vs. female) and gut-related diseases (chronic constipation, anorexia and cachexia) to drug absorption variability has not been firmly established yet. At the same time, a way to decrease oral drug pharmacokinetic variability is provided by the pharmaceutical industry: clinical evidence suggests that formulation approaches employed during drug development can decrease the variability in oral exposure. This review outlines the main drivers of oral drug exposure variability and potential approaches to overcome them, while highlighting existing knowledge gaps and guiding future studies in this area

Integratie van biorelevantie in de absorptie profilering van slecht in water oplosbare geneesmiddelen

status: publishe

Try before you buy Een onderzoek bij mensen thuis naar de relatie tussen leeftijd en de intentie om commerciële augmented reality te gebruiken, en de verklaringen voor deze relatie.

In deze tijd waarin de consument graag zelf bepaalt in hoeverre een product voor hen van toegevoegde waarde is, zien marketeers commerciële augmented reality (AR) als het ei van Columbus. Deze technologie voegt een virtuele laag toe aan de werkelijkheid, waardoor consumenten producten kunnen visualiseren in hun eigen fysieke omgeving. AR onderzoek houdt nog geen rekening met leeftijdsverschillen. Het huidige onderzoek probeert, met het Technology Acceptance Model (TAM) als theoretische basis, een antwoord te formuleren op de vraag of leeftijd invloed heeft op de intentie om commerciële AR te gebruiken. Daarbij zouden ease-of-use (gebruiksgemak), usefulness (nuttigheid) en enjoyment (plezier) als verklaringen kunnen dienen. Om dit te onderzoeken is een experiment in de thuissituatie van 71 participanten uitgevoerd. Tegen de verwachting in bleken jongvolwassenen en oudere volwassenen beide overwegend positief over de AR-technologie en een hoge gebruiksintentie te hebben. Dit is het eerste AR-onderzoek dat leeftijd meeneemt en waar onderzoek is verricht in de directe omgeving van participanten. Op basis van de bevindingen hoeven marketeers bij de inzet van commerciële AR doelgroepen niet te differentiëren op leeftijd. Vervolgonderzoek dient, vanwege een eventueel plafond-effect, te controleren in hoeverre mensen met meer ARervaring dezelfde hoge waardering laten zien