MicroPharm Ltd.

Newcastle Emlyn, United Kingdom

MicroPharm Ltd.

Newcastle Emlyn, United Kingdom
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Al-Abdulla I.,MicroPharm Ltd | Casewell N.R.,MicroPharm Ltd | Casewell N.R.,Alistair Reid Venom Research Unit | Casewell N.R.,Bangor University | Landon J.,MicroPharm Ltd
Toxicon | Year: 2013

An antivenom should be stable under the conditions that it will be both transferred and stored. Thus instability may lead to a loss of efficacy and an increased incidence and severity of adverse effects. Stability is a particular problem in countries where the temperatures and humidity are high. Here we investigate the stability of a liquid-formulated, intact ovine immunoglobulin-based antivenom, EchiTAbG™, which is used extensively in Nigeria to treat envenoming by the West African saw-scaled viper, Echis ocellatus. Ampoules of antivenom were assessed as to their specific antibody content by small scale affinity chromatography and their purity by size exclusion gel filtration and turbidity. Three different batches of the antivenom revealed no significant changes, using these assessment techniques, during 42 months storage at 4 °C or at ambient temperature, followed by one month at 37 °C. These real-time studies indicate that the antivenom remains stable for a minimum of 3.5 years and that it can be exposed to tropical temperatures without any loss in immunoglobulin binding activity. This further highlights the clinical utility of liquid formulated ovine IgG antivenoms by demonstrating their retention of potency in the event of a short term failing in the cold chain. © 2013 Elsevier Ltd.

Cherry C.L.A.,Cardiff Metropolitan University | Millward H.,Cardiff Metropolitan University | Cooper R.,Cardiff Metropolitan University | Landon J.,MicroPharm Ltd
Pharmaceutical Development and Technology | Year: 2014

A novel approach has been developed that enables sterile pharmaceutical products to be freeze-dried in the open laboratory without specialist facilities. The product is filled into vials, semi-stoppered and sealed inside one, followed by a second, sterilization pouch under class 100 conditions. The product is then freeze-dried in the laboratory where the vials are shelfstoppered before being returned to class 100, unwrapped and crimped. The sterilization pouches increased the resistance to water vapor movement during sublimation, thereby increasing the sublimation time and product temperature. Ovine immunoglobulins were double wrapped and lyophilized (as above) adjusting the primary drying time and shelf temperature for increased product temperature and, therefore, prevention of collapse. Ovine immunoglobulin G formulations freeze-dried to ≤1.1% residual moisture with no effect on protein aggregation or biological activity. The process was simulated with tryptone soya broth and no growth of contaminating microbial cells was observed after incubation at 35 °C for 2 weeks. Although increasing lyophilization time, this approach offers significant plant and validation cost savings when sterile freeze-drying small numbers of vials thereby making the manufacture of treatments for neglected and orphan diseases more viable economically. © 2014 Informa Healthcare USA, Inc.

Medically important cases of snakebite in Europe are predominately caused by European vipers of the genus Vipera. The mainstay of snakebite therapy is polyclonal antibody therapy, referred to as antivenom. Here we investigate the capability of the monospecific V. berus antivenom, ViperaTAb®, to cross-react with, and neutralise lethality induced by, a variety of European vipers. Using ELISA and immunoblotting, we find that ViperaTAb® antibodies recognise and bind to the majority of toxic components found in the venoms of the Vipera species tested at comparably high levels to those observed with V. berus. Using in vivo pre-clinical efficacy studies, we demonstrate that ViperaTAb® effectively neutralises lethality induced by V. berus, V. aspis, V. ammodytes and V. latastei venoms and at much higher levels than those outlined by regulatory pharmacopoeial guidelines. Notably, venom neutralisation was found to be superior to (V. berus, V. aspis and V. latastei), or as equally effective as (V. ammodytes), the monospecific V. ammodytes "Zagreb antivenom", which has long been successfully used for treating European snake envenomings. This study suggests that ViperaTAb® may be a valuable therapeutic product for treating snakebite by a variety of European vipers found throughout the continent.

Roberts A.,Public Health England | Mcglashan J.,Public Health England | Ibrahim I.A.,MicroPharm Ltd. | Ling R.,Public Health England | And 5 more authors.
Infection and Immunity | Year: 2012

Treatment of Clostridium difficile is a major problem as a hospital-associated infection which can cause severe, recurrent diarrhea. The currently available antibiotics are not effective in all cases and alternative treatments are required. In the present study, an ovine antibody-based platform for passive immunotherapy of C. difficile infection is described. Antibodies with high toxin-neutralizing titers were generated against C. difficile toxins A and B and were shown to neutralize three sequence variants of these toxins (toxinotypes) which are prevalent in human C. difficile infection. Passive immunization of hamsters with a mixture of toxin A and B antibodies protected them from a challenge with C. difficile spores in a dose-dependent manner. Antibodies to both toxins A and B were required for protection. The administration of toxin A and B antibodies up to 24 h postchallenge was found to reduce significantly the onset of C. difficile infection compared to nonimmunized controls. Protection from infection was also demonstrated with key disease isolates (ribotypes 027 and 078), which are members of the hypervirulent C. difficile clade. The ribotype 027 and 078 strains also have the capacity to produce an active binary toxin and these data suggest that neutralization of this toxin is unnecessary for the management of infection induced by these strains. In summary, the data suggest that ovine toxin A and B antibodies may be effective in the treatment of C. difficile infection; their potential use for the management of severe, fulminant cases is discussed. © 2012, American Society for Microbiology.

Al-Abdulla I.,MicroPharm Ltd | Casewell N.R.,MicroPharm Ltd | Landon J.,MicroPharm Ltd
Journal of immunological methods | Year: 2014

Antivenoms are typically produced in horses or sheep and often purified using salt precipitation of immunoglobulins or F(ab')2 fragments. Caprylic (octanoic) acid fractionation of antiserum has the advantage of not precipitating the desired antibodies, thereby avoiding potential degradation that can lead to the formation of aggregates, which may be the cause of some adverse reactions to antivenoms. Here we report that when optimising the purification of immunoglobulins from ovine antiserum raised against snake venom, caprylic acid was found to have no effect on the activity of the enzymes pepsin and papain, which are employed in antivenom manufacturing to digest immunoglobulins to obtain F(ab')2 and Fab fragments, respectively. A "single-reagent" method was developed for the production of F(ab')2 antivenom whereby whole ovine antiserum was mixed with both caprylic acid and pepsin and incubated for 4h at 37°C. For ovine Fab antivenom production from whole antiserum, the "single reagent" comprised of caprylic acid, papain and l-cysteine; after incubation at 37°C for 18-20h, iodoacetamide was added to stop the reaction. Caprylic acid facilitated the precipitation of albumin, resulting in a reduced protein load presented to the digestion enzymes, culminating in substantial reductions in processing time. The ovine IgG, F(ab')2 and Fab products obtained using these novel caprylic acid methods were comparable in terms of yield, purity and specific activity to those obtained by multi-step conventional salt fractionation with sodium sulphate. Copyright © 2013 Elsevier B.V. All rights reserved.

Jones R.G.A.,MicroPharm Ltd. | Martino A.,SGS UK Ltd.
Journal of Pharmaceutical and Biomedical Analysis | Year: 2016

Highly purified specific Fab antibody fragments derived from sheep have a long history of therapeutic use as safe and effective emergency medicines. In more recent years simple low-cost methods have been developed, which take advantage of the ability of pepsin under optimally controlled conditions to preferentially digest ovine IgG within the Fc region to produce F(ab')2 and easy to remove low MW Fc sub-fragments. Despite these developments no information is currently available on the pepsin digestion of ovine IgG at the amino acid level hindering the development of improved F(ab')2 processing methods. To gain knowledge of the fragments properties we have constructed linear models of ovine IgG1 and IgG2 subclasses, starting from the gamma-1 and gamma-2 chain amino acid sequences, which also incorporate the inter- and intra-chain disulphide bonds. Any potential pepsin cleavage site was initially predicted in silico, then high probability points identified for each of the molecules and mapped onto the individual models. A theoretical order of digestion was subsequently constructed, which appeared to agree with the experimental data, suggesting an accurate prediction model for ovine IgG1 and IgG2 subclasses. These findings lay the foundations for a more detailed analysis of pepsin cleavage fragments in the future. Additionally, the F(ab')2 generated following pepsin digestion were predicted to contain subclass unique C-terminal octapeptide neoepitopes, despite the high 89% sequence identity of the intact gamma-1 and gamma-2 chain constant regions. These neoepitopes have the potential to be utilised for identification purposes once confirmed experimentally. © 2015 Elsevier B.V.

Micropharm Ltd and Public Health England | Date: 2014-03-18

The present invention provides an antibody composition comprising ovine antibodies, for use in the prevention or treatment of C. difficile infection wherein the antibodies bind to a C. difficile toxin.

MICROPHARM Ltd and Public Health England | Date: 2011-10-05

The present invention relates to recombinant Clostridium difficile antigens based on a fusion protein that consists of or comprises a first amino acid sequence and a second amino acid sequence, wherein: a) the first amino acid sequence is provided by an amino acid sequence that has at least 80% sequence identity with an amino acid sequence consisting of residues 500-1850 of a C. difficile Toxin A sequence or residues 1500-1851 of a C. difficile Toxin B sequence; and b) the second amino acid sequence is provided by an amino acid sequence that has at least 80% sequence identity with an amino acid sequence consisting of a long repeat unit located within amino acid residues 1851-2710 of a C. difficile Toxin A sequence or within amino acid residues 1852-2366 of a C. difficile Toxin B sequence; though with the proviso that the fusion protein is not a polypeptide comprising amino acid residues 543-2710 of a C. difficile Toxin A and with the proviso that the fusion protein is not a polypeptide comprising amino acid residues 543-2366 of a C. difficile Toxin B. Also provided is the use of said antigens for the prevention/treatment/suppression of Clostridium difficile infection (CDI), together with methods for generating said antigens, methods for generating antibodies that bind to said antigens, and the use of said antibodies for the prevention/treatment/suppression of CDI.

Agency: GTR | Branch: Innovate UK | Program: | Phase: Collaborative Research & Development | Award Amount: 2.07M | Year: 2013

One of the commonest causes of hospital acquired infection is the bacterium Clostridium difficile which causes diarrhoea and other effects by releasing two powerful toxins. Such infections far outnumber those due to MRSA and the Centre for Disease Control and Prevention in the USA has noted “...the incidence of deaths from C.difficile is greater than the extent of deaths from all the other intestinal diseases combined.” The present project involves a novel means of treating patients with severe C. difficile infections by injecting specific antibodies which bind to, and neutralise the toxins. The antibodies are produced by immunising sheep with miniscule amounts of inactivated toxins (similar to the vaccination of infants) and the antibodies are separated from other blood constituents, purified and filled into ampoules ready for intravenous administration as an adjunct to antibiotic therapy.

Micropharm Ltd and Public Health England | Date: 2010-02-19

The present invention provides an antibody composition comprising ovine antibodies, for use in the prevention or treatment of C. difficile infection wherein the antibodies bind to a C. difficile toxin.

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