Standardization of allergen products: 3. Validation of candidate European Pharmacopoeia standard methods for quantification of major birch allergen Bet v 1.

BACKGROUND: The BSP090 project aims at establishing European Pharmacopoeia Reference Substances in combination with the corresponding ELISA methods for the quantification of major allergens in allergen products. Two sandwich ELISAs proved suitable for quantification of Bet v 1, the major birch pollen allergen, in preceding phases of BSP090. METHODS: Two Bet v 1-specific ELISA systems were compared with respect to accuracy and precision in a ring trial including 13 laboratories. Model samples containing recombinant rBet v 1.0101 as well as native birch pollen extracts were measured independently at least three times in each facility. The assessment was completed with a comparative quantification of Bet v 1 in 30 marketed birch allergen products in one laboratory, simulating the future use as reference method. RESULTS: In the collaborative study, both candidate ELISAs confirmed their suitability to quantify recombinant and native Bet v 1. ELISA-A showed higher precision and lower interlaboratory variability, yet ELISA-B exhibited slightly higher accuracy. Subsequent parallel measurement of Bet v 1 in a panel of 'real-life' birch allergen products indicated better repeatability of ELISA-B. Both systems detected substantial differences in Bet v 1 content between allergen products, but the effect was more pronounced using ELISA-B due to persistently higher values compared to ELISA-A. CONCLUSIONS: In the collaborative study, no deciding differences were observed between the two candidate ELISAs. Further comparison under conditions simulating the intended use combined with the criterion of long-term availability enabled the selection of one Bet v 1-specific ELISA for proposal as European Pharmacopoeia standard method.

Assay discrepancies using human coagulation factor VIII chromogenic kits: Results from a plasma-derived factor VIII collaborative study (BSP112).

Chromogenic assay discrepancies were reported at General European Official Medicines Control Laboratories Network (GEON) meetings by laboratories testing FVIII-products. The objectives of the present investigation were to carry out a controlled collaborative study to examine these reports and to delineate the reasons for these discrepancies by assessing affected and unaffected FVIII products. The laboratories followed a strict study protocol, which included assessing their own individual observed factor X (FX) activation times, i.e. the time to reach 50% of maximal FX activation (T1/2), for each chromogenic kit. This measurement was used, in parallel with the kit manufacturers' prescribed FX activation times, to assess the performance of the chromogenic potency assays on FVIII test products. This study confirmed a significant discrepancy between Coatest® and Coamatic® kits and between Siemens and Coamatic® kits when the kit manufacturers' prescribed T1/2 incubation times were followed. Coamatic® kits tended to produce higher potencies than the Coatest® or Siemens kits. Furthermore, FX activation assays revealed marked differences between individual laboratories for all three chromogenic kits in the observed T1/2 incubation times, which also did not correspond to the prescribed T1/2 incubation times. The resulting differences in potency between kits, in some cases, were significantly reduced when using the actual observed T1/2 incubation times instead of the prescribed T1/2 incubation times. The study showed that FVIII potency discrepancies can occur between chromogenic kits. To compensate for this, laboratories should ideally perform FX activation curves for each new chromogenic kit in order to determine the correct observed T1/2 incubation times, which can then be used to determine FVIII potencies in therapeutic concentrates.

Peripapillary and optic nerve head vessel density of glaucoma and healthy subjects from Afro-Caribbean and European descent: A pilot study.

PURPOSE: To compare the peripapillary and optic nerve head vessel density (PP-ONH VD) between glaucoma patients (all, early, moderated, and advanced) and healthy subjects of Afro-Caribbean descent (AD) and European descent (ED). METHODS: This was a cross-sectional study. One eye was evaluated in 90 subjects, including 66 glaucoma patients and 24 healthy subjects, who underwent PP-ONH VD imaging using SPECTRALIS® Optical Coherence Tomography Angiography (OCT-A). We analysed the superficial vascular complex using the AngioTool version 0.6a software. The correlation between the PP-ONH VD and visual field mean deviation (MD) was evaluated using a scatter plot and Spearman's rho correlation coefficient. RESULTS: Among the healthy subjects, the AD group had a lower superficial PP-ONH VD [43.29±3.25% (mean±standard deviation)] than the ED group (46.06±1.75%) (P=0.016). Overall, superficial PP-ONH VD did not show any significant differences between the total AD and ED glaucoma patients or in the subgroup analyses (early/moderate/advanced) (AD: 32.73±6.70%, 37.11±5.72%, 32.48±5.73%, 27.76±4.74%, respectively; ED: 33.94±6.89%, 38.52±3.82%, 35.56±4.18%; 27.65±6.31%, respectively) (P>0.05 for all). A strong, statistically significant correlation was established between vessel density and mean deviation among AD and ED glaucoma patients (r=0.709 and r=0.704, respectively) (P<0.001 for both). CONCLUSION: This pilot study shows that healthy subjects of AD had lower peripapillary and optic nerve head superficial vessel density than healthy subjects of ED, but no significant differences were found between AD and ED glaucoma groups (all, early, moderate, or advanced).

Collaborative study for the validation of alternative in vitro potency assays for human tetanus immunoglobulins.

An international collaborative study to validate 2 alternative in vitro methods for the potency testing of human tetanus immunoglobulin products was organised by the European Directorate for the Quality of Medicines & HealthCare (EDQM). The study, run in the framework of the Biological Standardisation Programme (BSP) under the aegis of the European Commission and the Council of Europe, involved 21 official medicines control and industry laboratories from 15 countries. Both methods, an enzyme-linked immunoassay (EIA) and a toxoid inhibition assay (TIA), showed good reproducibility, repeatability and precision. EIA and TIA discriminated between low, medium and high potency samples. Potency estimates correlated well and both values were in close agreement with those obtained by in vivo methods. Moreover, these alternative methods allowed to resolve discrepant results between laboratories that were due to product potency loss and reporting errors. The study demonstrated that EIA and TIA are suitable quality control methods for tetanus immunoglobulin, which can be standardised in a control laboratory using a quality assurance system. Consequently, the Group of Experts on Human Blood and Blood Products of the European Pharmacopoeia revised the monograph on human tetanus immunoglobulins to include both the methods as compendial alternatives to the in vivo mouse challenge assay.

Collaborative study for the validation of cell line assays for in-process toxicity and antigenicity testing of Clostridium septicum vaccine antigens - Part 1.

Large numbers of mice are used in testing during the production of Clostridial vaccines. Previous work has indicated that cell line assays could replace mouse tests for certain aspects of this testing. Replacement assays have been developed for the testing of the toxins and toxoids of several clostridial species but none of these assays have been assessed in an international collaborative study. Under the common aegis of the European Partnership for Alternative Approaches to Animal Testing (EPAA) and of the European Directorate for the Quality of Medicines & HealthCare (EDQM), collaborative study BSP130 was initiated to evaluate Vero cell based alternative methods to the current mouse tests used to measure the toxicity of Clostridium septicum toxin (the minimum lethal dose (MLD) test), the freedom from toxicity of C. septicum toxoid (the MLD test) and the antigenicity of C. septicum toxoid (the total combining power (TCP) test). The principal aims of BSP130 were to determine the repeatability and reproducibility of the in vitro assays and to demonstrate concordance of the proposed in vitro and current in vivo TCP and MLD tests. 11 laboratories from 7 countries participated in the collaborative study and each tested 6 toxins and 6 toxoids. The participants' Vero cell lines were up to 1 000 times more sensitive than the mouse strains. The MLD assay in mice and on Vero cells generally ranked the toxins in a similar order in most of the laboratories. The TCP assay in mice and on Vero cells also generally ranked the toxoids in a similar order in most of the laboratories. The results demonstrate that the repeatability and reproducibility of the in vitro Vero cell based assays are no worse than that of the in vivo assays and that they are easily transferable to other laboratories. The concordance correlations between the in vivo and in vitro methods were for the MLD assays ρc=0.961 (log-transformed values) and ρc=0.921 (non-log-transformed values) and for the TCP assays ρc=0.968 (log-transformed values) and ρc=0.980 (non log-transformed values). These correlations are excellent showing that the Vero cell assays can be used as alternatives to the mouse tests for the assessment of C. septicum toxin MLD and toxoid TCP values. This study can be used by vaccine manufacturing companies as a guide for applying the same approach to other clostridial toxins and toxoids.

Production and characterisation of a candidate hyper-immune serum for the replacement of the Bordetella pertussis mouse antiserum Biological Reference Preparation.

For acellular pertussis (aP) vaccines, the current European Pharmacopoeia (Ph. Eur.) monograph Pertussis vaccine (acellular, component, adsorbed) (1356) requires an immunogenicity assay in mice or guinea pigs to assess the potency of each lot of vaccine (Ph. Eur. general method 2.7.16. Assay of pertussis vaccine (acellular)). This biological assay, carried out on the final bulk of the vaccine lot, is based on the measurement of the specific antibody response to the 5 antigenic components (pertussis toxin (PT), Fimbrial haemagglutinin (FHA), pertactin (PRN) and Fimbriae 2 and 3 (FIM2/3)) that are present in the combined aP vaccines. In the mouse assay, serum antibody levels are measured by ELISA. The immunogenicity of a vaccine under test is estimated versus a homologous reference vaccine and a reference antiserum e.g. the first Ph. Eur. Biological Reference Preparation for Bordetella (B.) pertussis mouse anti-serum (BRP1), established in 1998, is used to normalise the titre of antibodies (expressed in ELISA Units (ELU)/mL). In anticipation of the depletion of BRP1 stocks, a project was launched in 2013 by the Biological Standardisation Programme (BSP) of the European Directorate for the Quality of Medicines & HealthCare (EDQM) in order to establish a new standardised reference serum. The project, referred to herein as BSP129, was conducted in 2 phases: 1) the production and characterisation of a mouse serum pool (using a multicomponent aP vaccine marketed in Canada similar to the vaccine used in the BRP1 production as immunogen) and of candidate BRP batches (cBRPs) and 2) an international collaborative study aimed at calibrating the cBRPs in terms of antibody levels against PT, FHA, PRN and FIM2/3. This article presents the design and results of the first phase of the collaborative study to establish the optimal conditions for immunisation and bleeding of mice in order to produce a large pool of hyper-immune serum against the 5 antigens. After the characterisation of this pool, cBRP pilot lots were manufactured by freeze-drying diluted solutions of the hyper-immune serum pool. The pilot lots were then characterised in two Official Medicines Control Laboratories (OMCLs) for their antibody contents against aP vaccine antigens using in-house ELISA (based on methods developed by 2 European vaccine manufacturers) and Multiplex Immunoassay (MIA) methods. The antibody titres recovered demonstrated that a dilution factor of 1/40 could be considered for the scaled-up manufacture of candidate reference preparations (cBRPs). Three batches (15 000 vials) of cBRP were manufactured and fully characterised. In light of the data obtained, and although titration results between the ELISA methods were sometimes discrepant, it was agreed that the establishment study (phase 2) could be launched. Real-time and accelerated stability studies were also included in the first study phase to document the stability of the cBRPs in freeze-dried form and after reconstitution and storage at -20°C±5°C. The results showed that the stability of the freeze-dried cBRPs at usual storage and shipment temperatures is acceptable and that reconstituted cBRP solutions are stable for 12 months at -20°C±5°C. It could therefore be recommended to freeze small aliquots of the 1 mL solution obtained by the reconstitution of one BRP vial in order to store them for use in separate assays. With the application of this strategy, the stocks of the BRP1 replacement batches should cover the needs of OMCLs and manufacturers for at least the next decade.

Establishment of an erythropoietin CRS with stable measurable dimer content for SEC system suitability qualification

The European Pharmacopoeia (Ph. Eur.) monograph 1316 'Erythropoietin concentrated solution' prescribes that the dimer content of therapeutic erythropoietin (EPO) preparations must not exceed 2% as determined by Size-Exclusion Chromatography (SEC). This report describes the evaluation of a candidate Chemical Reference Substance (cCRS) to serve as system suitability reference material for the qualification of SEC systems used to assess dimer and oligomer content in EPO solutions. The study organised by the European Directorate for the Quality of Medicines & HealthCare (EDQM) was performed with the participation of six European laboratories which tested the candidate material and the EPO for physicochemical tests CRS batch 1. The candidate material was shown to be a suitable reference material for the determination of the resolving capability of the SEC system for separation of dimer and higher oligomers from monomeric EPO. The cCRS was adopted by the Ph. Eur. Commission as Erythropoietin for SEC system suitability CRS batch 1 following consideration of the report. The importance of the resolving capability of the SEC system, as defined by the peak ratios or the peak-to-valley resolution, together with the asymmetry of the peaks eluted, and the linear response of the UV detector were all seen as critical parameters. Therefore, the monograph Erythropoietin concentrated solution (1316) was revised concomitantly to take account of the CRS and to set acceptance criteria for these critical parameters..

Establishment of replacement batches for prekallikrein activator in albumin biological reference preparation.

A collaborative study was run by the European Directorate for the Quality of Medicines and HealthCare (EDQM) under the aegis of the Biological Standardisation Programme (BSP) to establish replacement batches of the current Prekallikrein activator in albumin Biological Reference Preparation (BRP) batch 1, the stocks of which were dwindling. Candidate BRP replacement batch 2 and batch 3 were assayed against the 2nd World Health Organization International Standard for Prekallikrein activator, human (2nd IS) and the Prekallikrein activator in albumin BRP batch 1. The candidate batches were manufactured from the same starting material as the current Biological Reference Preparation and the 2nd IS. They consisted of a 20 % solution of albumin lyophilised under the same conditions as the Prekallikrein activator in albumin BRP batch 1. Sixteen laboratories participated in the collaborative study and were requested to assay the candidates by their routine method, complying with the European Pharmacopoeia (Ph. Eur.) general method 2.6.15 for the determination of prekallikrein activator content. A central statistical analysis was performed at the EDQM using in-house calculations of prekallikrein activator contents provided by the participating laboratories. On the basis of the results of this study, which confirmed the assigned potency of 29 IU/vial of Prekallikrein activator in albumin BRP batch 1, the 2 candidate materials were assigned a potency of 30 IU/vial. The 2 candidates were adopted by the Ph. Eur. Commission in March 2008 as Ph. Eur. Prekallikrein activator in albumin Biological Reference Preparation batch 2 and batch 3.

Establishment of a replacement batch for heparin sodium biological reference preparation.

An international collaborative study was organised to replace the current European Pharmacopoeia biological reference preparation for heparin sodium. The project was organised by the European Directorate for the Quality of Medicines & HealthCare in the frame of its Biological Standardisation Programme. A suitable candidate batch representative of the quality of heparin products currently marketed in Europe was donated to the EDQM and included in a collaborative study involving 19 laboratories from 10 European countries, the Americas, Australia and the Council of Europe. Laboratories were requested to perform their routine assays following the prescriptions of the Ph. Eur. for the assay and the identification of unfractionated heparin and for the assay of protamine. The results made it possible to demonstrate that the candidate batch was suitable for its intended use and it was therefore established by the European Pharmacopoeia Commission as the Ph. Eur. heparin sodium BRP batch 3 in June 2007.

Collaborative study for the establishment of a candidate equine influenza subtype 2 American-like strain A/EQ/South Africa/4/03 - horse antiserum biological reference preparation.

In 2004, the Office International des Epizooties (OIE) Expert Surveillance Panel on equine influenza recommended that the American lineage component (H3N8) of equine influenza vaccines (A/eq/Newmarket/1/93-like) be updated to an A/eq/South Africa/4/03-like virus. As a consequence the common European Pharmacopoeia (Ph. Eur.) - OIE reference for equine influenza subtype 2 American-like antiserum had to be complemented by an antiserum raised in horses against an A/eq/South Africa/4/03 strain. An international collaborative study run by the European Directorate for the Quality of Medicines (EDQM) in the frame of its Biological Standardisation Programme (BSP) under the aegis of the Ph. Eur. and the OIE was organised. The study was aimed at evaluating a candidate reference horse anti-serum using the single radial haemolysis (SRH) and haemagglutination inhibition (HI) tests. The standard was to be established for use in immunogenicity and batch potency assay of equine influenza vaccines as a Ph. Eur. BRP and for use in clinical diagnostic tests as an OIE-approved International Standard. The evaluation performed in the collaborative study enabled the suitability of the candidate to be demonstrated and an SRH value to be assigned. The candidate was adopted as a BRP by the Ph. Eur. Commission and approved by the OIE Biological Standards Commission as an International Standard Serum in June and September 2006, respectively.

Collaborative study for the establishment of erythropoietin BRP batch 3.

The European Pharmacopoeia (Ph. Eur.) monograph on Erythropoietin concentrated solution (1316) specifies that identification and assay are performed using pharmacopoeial methods requiring the use of a reference preparation. To replace the current erythropoietin Biological Reference Preparation (BRP) of Ph. Eur., in 2006, the European Directorate for the Quality of Medicines undertook a collaborative study designed to establish a replacement batch. In order to guarantee continuity, the formulation of the candidate batch was similar to that of previous batches (1 and 2). The methods chosen to qualify the new standard were those included in the current monograph. The study was defined to allow calibration of the candidate by in vivo bioassay in terms of the current World Health Organization (WHO) International Standard (IS) and to assign a unitage. The suitability of the candidate preparation to serve as a reference standard for the other pharmacopoeial analytical procedures was also investigated. The collaborative study involved 16 laboratories from Europe, Australia, Canada, China, Japan, South Korea and the United States of America. Participants carried out biological and physicochemical assays on the candidate erythropoietin BRP batch 3 (cBRP3), using batch 2 (BRP2) and where necessary the 2nd World Health Organization International Standard (WHO 2nd IS) for recombinant erythropoietin as the reference standards. It was demonstrated that the replacement batch is appropriate for use as erythropoietin BRP in the context of the control of erythropoietin concentrated solutions according to the Ph. Eur. monograph (1316). However as regards the potency of BRP2 and cBRP3 in the mouse bioassay unexpected observations were made. Direct calibration of BRP2 against the WHO 2nd IS yielded, in all laboratories, results that were systematically higher than the potency of 32,500 IU/vial assigned by direct calibration against the WHO 2nd IS in the former study. It was therefore recommended to assign the potency of cBRP3 against BRP2, using the average of all results that were not considered as outlying obtained in the collaborative study, in order to guarantee continuity of unitage between the successive BRP batches. The outcome of the study enabled the Ph. Eur. Commission to establish the proposed standard as 'erythropoeitin BRP batch 3' (BRP3). BRP3 was established in June 2007 for use as a reference preparation for the polycythaemic and normocythaemic mouse bioassay, with an assigned potency of 35,280 IU/vial, the identification by capillary zone electrophoresis, by polyacrylamide gel electrophoresis, immunoblotting and peptide mapping and as a reference for checking the system suitability of size-exclusion chromatographic procedures used in the test for dimers and related substances of higher molecular mass in the Ph. Eur. monograph (1316).

Collaborative study on saccharide quantification of the Haemophilus influenzae type b component in liquid vaccine presentations.

Before release onto the market, it must be demonstrated that the total and free polysaccharide (poly ribosyl-ribitol-phosphate, PRP) content of Haemophilus influenzae type b (Hib) vaccine complies with requirements. However, manufacturers use different methods to assay PRP content: a national control laboratory must establish and validate the relevant manufacturer methodology before using it to determine PRP content. An international study was organised by the World Health Organization (WHO), in collaboration with the Biological Standardisation Programme (BSP) of the Council of Europe/European Directorate for the Quality of Medicines & HealthCare (EDQM) and of the European Union Commission, to verify the suitability of a single method for determining PRP content in liquid pentavalent vaccines (DTwP-HepB-Hib) containing a whole-cell pertussis component. It consists of HCl hydrolysis followed by chromatographic separation and quantification of ribitol on a CarboPac MA1 column using high-performance anion exchange chromatography coupled with pulsed amperometric detection (HPAEC-PAD). The unconjugated, free, PRP is separated from the total PRP using C4 solid-phase extraction cartridges (SPE C4). Ten quality control laboratories performed two independent analyses applying the proposed analytical test protocol to five vaccine samples, including a vaccine lot with sub-potent PRP content and very high free PRP content. Both WHO PRP standard and ribitol reference standard were included as calibrating standards. A significant bias between WHO PRP standard and ribitol reference standard was observed. Study results showed that the proposed analytical method is, in principle, suitable for the intended use provided that a validation is performed as usually expected from quality control laboratories.

Calibration of the Ph. Eur. human coagulation Factor VIII concentrate BRP batch 5.

The European Pharmacopoeia Biological Reference Preparation (Ph. Eur. BRP) for Factor VIII Concentrate batch 5 was established through a collaborative study involving 14 laboratories organised by the European Directorate for the Quality of Medicines & HealthCare (EDQM, Council of Europe) to be used as working standard for potency determination of human coagulation Factor VIII (FVIII) preparations. The potency of the BRP batch 5 was assigned with reference to the WHO 8th International Standard (IS) for FVIII Concentrate and the BRP batch 4. Participants were instructed to perform 3 independent Factor VIII potency assays following their own routine validated methods by the chromogenic assay as it is the assay prescribed by the European Pharmacopoeia. This publication reports the results obtained during the study. The consensus potency, 9.9 IU/ampoule (n = 14) when assessed against both standards, with inter-laboratory geometric coefficients of variation (GCV) of 3.2 % and 1.9 % against the WHO 8th IS and the BRP batch 4 respectively, was consistent with the expected value. The Ph. Eur. BRP batch 5 is a freeze-dried, plasma-derived concentrate. Based on accelerated degradation studies, the stability of the material is suitable as a reference preparation. The Ph. Eur. BRP batch 5 was adopted at the 151st session of the European Pharmacopoeia Commission in March 2015 and is available from the EDQM.

Establishment of the Ph. Eur. Hepatitis A virus RNA for NAT testing BRP batch 1.

Detection of viral contamination in plasma donations is critical to prevent transmission of infectious diseases. The European Pharmacopoeia (Ph. Eur.) monograph 1646 'Human plasma (pooled and treated for virus inactivation)', requires that plasma pools used for the manufacture of this product be tested, among others, for the presence of hepatitis A virus RNA by nucleic acid testing (NAT) using a positive control containing 100 International Units (IU) of hepatitis A virus (HAV) RNA per mL. To this end, the European Directorate for the Quality of Medicines & HealthCare (EDQM, Council of Europe) organised an international collaborative study under the aegis of the Biological Standardisation Programme, for the establishment of the 1st Biological Reference Preparation (BRP) for HAV RNA for NAT testing. A freeze-dried candidate material was thus prepared and calibrated against the WHO 2nd International Standard for HAV for NAT (00/562) in a study in which thirteen European and North American laboratories including Official Medicines Control Laboratories (OMCLs), manufacturers of plasma-derived products, producers of in vitro diagnostic kits and a blood transfusion centre participated. Based on the outcome of the study, an HAV RNA content of 40 000 IU/vial (corresponding approximately to 4.6 log10 IU/vial) was assigned to the BRP, which was adopted by the Ph. Eur. Commission in March 2016 as Ph. Eur. hepatitis A virus RNA for NAT testing BRP batch 1.

Assessment of UV spectrophotometry for determination of plasmid DNA concentration in vector preparations for human gene therapy products.

The European Pharmacopoeia (Ph. Eur.) general chapter 5.14. Gene transfer medicinal products for human use suggests the use of absorbance measurements at 260 nm to determine the DNA concentration of plasmid vectors used for the preparation of gene therapy products for human use. An international collaborative study was organised by the European Directorate for the Quality of Medicines & HealthCare (EDQM) to confirm the suitability of UV spectrophotometry for the quantification of plasmid vectors used in gene therapy (GT). Three Official Medicine Control Laboratories (OMCLs of the European OMCL Network) and members of the OMCL Working Group for GT products took part in the study, in which various types of spectrophotometers were assessed using common test samples. Results of the study demonstrated that UV spectrophotometry can be considered suitable for the quantification of plasmid DNA in GT products regardless of the instrument used.

Validation of ELISA methods for quantification of the major birch allergen Bet v 1 (BSP090).

To date, the potency of allergen products in Europe is expressed in manufacturer-specific units relative to a product-specific in-house reference. Consequently, cross-product comparability of allergen products from different manufacturers with respect to strength and efficacy is impossible. The Biological Standardisation Programme (BSP) project BSP090 addresses this issue via the establishment of reference standards in conjunction with ELISA methods for the quantification of major allergens in allergen products. Since the initiation of BSP090, the recombinant major allergen Bet v 1 has been adopted by the European Pharmacopoeia Commission as a Chemical Reference Substance (CRS). In parallel, two sandwich ELISA systems for quantification of Bet v 1 were found suitable in preliminary phases of BSP090 to be validated in a large collaborative study. In this study, the candidate ELISA systems were compared with respect to accuracy, precision and variability. Thirteen participating laboratories tested model samples containing the CRS as well as spiked and unspiked birch pollen extracts. Both in pre-testing and in the collaborative study, the 2 candidate ELISA systems confirmed their suitability to quantify recombinant and native Bet v 1. As no clear-cut decision for one of the ELISA systems could be made based on the results of the collaborative study, a post-study testing was performed. Bet v 1 content of 30 birch pollen allergen products was determined in parallel in both ELISA systems. Consequently, 1 candidate ELISA system was selected to be proposed as the future European Pharmacopoeia standard method for Bet v 1 quantification.

Establishment of European pharmacopoeia Mycoplasma reference strains.

European Pharmacopoeia (Ph. Eur.) general chapter 2.6.7. Mycoplasma requires for the culture test reference strains of mycoplasma field isolates with fewer than 15 passages for validation and run control and in the test for inhibitory substances. Low passage field isolates of 5 mycoplasma strains (Mycoplasma hyorhinis, Mycoplasma synoviae, Mycoplasma fermentans, Mycoplasma orale and Acholeplasma laidlawii) have been prepared for this purpose and a small scale collaborative study involving European laboratories was carried out to confirm the suitability of the material for the intended purpose. Strains were prepared as 1 ml samples in frozen format and are stored below -60 degrees C. Each laboratory determined a titre for the material on their in-house media. A secondary part of the study also compared the growth of prediluted samples on the different culture media. Results of the study confirm that the material is suitable for use as a biological reference preparation (BRP) and an estimated titre has been provided for each strain based on the results of the study. It was noted that differences in the culture media used in the different laboratories did not have a detrimental effect on titre estimation. The estimated titre is intended as a guide for users to validate the use of the reference material in house. The candidate BRPs were adopted by the European Pharmacopoeia Commission on June 28, 2006 and are available for use from EDQM. A revision to chapter 2.6.7, including reference to the use of nucleic acid amplification techniques (NAT) was also adopted in June 2006 and will appear in the European Pharmacopoeia version 5.8 in January 2007 and come into force the 1st of July 2007. While it was not part of the study a number of participants also performed in-house NAT assays on the study material. Preliminary findings from these studies are presented.

Establishment of the human coagulation factor VII concentrate European Pharmacopoeia biological reference preparation batch 1.

For the potency assay of human coagulation factor VII concentrate preparations according to the European Pharmacopoeia (Ph. Eur.) a reference preparation calibrated in International Units (IU) is needed. Currently, the 1st International Standard (97/592, potency: 6.3 IU/ampoule) but no Ph. Eur. reference preparation is available. A collaborative study was run to calibrate a candidate Ph. Eur. Biological Reference Preparation (BRP) for human coagulation factor VII concentrate against the 1st International Standard; the BRP is intended to be used as working standard. A candidate BRP batch 1 was produced from a plasma-derived human factor VII concentrate preparation available on the European market. It fulfilled the requirements of a BRP with regard to precision and homogeneity of fill, residual water content and stability. In addition, the content of activated factor VII was low. Sixteen laboratories from 9 countries participated in the collaborative study. The potency of the candidate BRP was determined using the participants' chromogenic assay based on the Ph. Eur. and their in-house clotting assay, if available. The statistical model used for analysis of the results from most laboratories was the maximum likelihood of the parallel line model following a logarithmic transformation of the responses. In the chromogenic assay, a potency estimate of 8.2 IU/vial (+/-3.7%) was obtained for the candidate BRP. Results from the clotting assay were lower and less homogenous (6.7 IU/vial+/-11.6%). The results from the collaborative study showed that the candidate BRP is suitable as a reference standard for the chromogenic assay according to the Ph. Eur. It was adopted by the Ph. Eur. Commission in March 2006 as official Ph. Eur. BRP for this purpose.

Collaborative study for the establishment of replacement batches for somatropin CRS batch 1.

A project was run for the establishment of replacement batches of the European Pharmacopoeia (Ph. Eur.) Somatropin Chemical Reference Substance (CRS) batch 1. Twenty two laboratories from 16 countries took part in a collaborative study aimed at demonstrating the suitability of the candidate reference preparations to serve as working references in the tests for identification by peptide mapping and capillary electrophoresis (CE); related proteins, dimers and related substances of higher molecular mass; charged variants distribution; and/or for the assay of somatropin, as performed in accordance with the specifications of the current Ph. Eur. monographs 0950 Somatropin bulk solution, 0951 Somatropin and 0952 Somatropin for injection. Further to the completion of the study the Ph. Eur. Commission adopted one candidate in March 2006 as somatropin CRS batch 2 (with an assigned content of 1.69 mg somatropin monomer per vial) and the second one in June 2006 as somatropin/desamidosomatropin resolution mixture CRS batch 1 (prescribed use of the latter standard is restricted to the test for related proteins).

Collaborative study to establish human immunoglobulin BRP batch 3 and human immunoglobulin (molecular size) BRP batch 1.

A study was carried out by the European Directorate for the Quality of Medicines (EDQM) as part of the joint Biological Standardisation Programme of the Council of Europe and the European Commission with the aim to establish replacement batches of the European Pharmacopoeia (Ph. Eur.) human immunoglobulin Biological Reference Preparation (BRP) batch 2. Twenty-eight laboratories participated in this study. The suitability of the candidate reference preparations to serve as working references in the tests for distribution of the molecular size, anticomplementary activity and Fc function, in accordance with the specifications of the Ph. Eur. monographs Human normal immunoglobulin for intravenous administration (0918), Human normal immunoglobulin (0338) and Anti-T lymphocyte immunoglobulin for human use, animal (1928) was demonstrated. The candidates were therefore established as human immunoglobulin BRP batch 3 and Human immunoglobulin (molecular size) BRP batch 1. The prescribed use of the latter BRP is limited to the test for distribution of molecular size.