Argatroban versus heparin in patients without heparin-induced thrombocytopenia during venovenous extracorporeal membrane oxygenation: a propensity-score matched study.

BACKGROUND: During venovenous extracorporeal membrane oxygenation (vvECMO), direct thrombin inhibitors are considered by some potentially advantageous over unfractionated heparin (UFH). We tested the hypothesis that Argatroban is non-inferior to UFH regarding thrombosis and bleeding during vvECMO. METHODS: We conducted a propensity-score matched observational non-inferiority study of consecutive patients without heparin-induced-thrombocytopenia (HIT) on vvECMO, treated between January 2006 and March 2019 in the medical intensive care unit at the University Hospital Regensburg. Anticoagulation was realized with UFH until August 2017 and with Argatroban from September 2017 onwards. Target activated partial thromboplastin time was 50 ± 5seconds in both groups. Primary composite endpoint was major thrombosis and/or major bleeding. Major bleeding was defined as a drop in hemoglobin of ≥ 2 g/dl/day or in transfusion of ≥ 2 packed red cells/24 h, or retroperitoneal, cerebral, or pulmonary bleeding. Major thrombosis was defined as obstruction of > 50% of the vessel lumen diameter by means of duplex sonography. We also assessed technical complications such as oxygenator defects or pump head thrombosis, the time-course of platelets, and the cost of anticoagulation (including HIT-testing). RESULTS: Out of 465 patients receiving UFH, 78 were matched to 39 patients receiving Argatroban. The primary endpoint occurred in 79% of patients in the Argatroban group and in 83% in the UFH group (non-inferiority for Argatroban, p = 0.026). The occurrence of technical complications was equally distributed (Argatroban 49% vs. UFH 42%, p = 0.511). The number of platelets was similar in both groups before ECMO therapy but lower in the UFH group after end of ECMO support (median [IQR]: 141 [104;198]/nl vs. 107 [54;171]/nl, p = 0.010). Anticoagulation costs per day of ECMO were higher in the Argatroban group (€26 [13.8;53.0] vs. €0.9 [0.5;1.5], p < 0.001) but not after accounting for blood products and HIT-testing (€63 [42;171) vs. €40 [17;158], p = 0.074). CONCLUSION: In patients without HIT on vvECMO, Argatroban was non-inferior to UFH regarding bleeding and thrombosis. The occurrence of technical complications was similarly distributed. Argatroban may have less impact on platelet decrease during ECMO, but this finding needs further evaluation. Direct drug costs were higher for Argatroban but comparable to UFH after accounting for HIT-testing and transfusions.

Comparison of Bivalirudin Versus Heparin for Maintenance Systemic Anticoagulation During Adult and Pediatric Extracorporeal Membrane Oxygenation.

OBJECTIVES: To provide a comparative analysis of conventional heparin-versus bivalirudin-based systemic anticoagulation in adult and pediatric patients supported on extracorporeal membrane oxygenation. DESIGN: Retrospective chart review study of adult and pediatric patients receiving extracorporeal membrane oxygenation from January 1, 2014, to October 1, 2019. SETTING: A large, high-volume tertiary referral adult and pediatric extracorporeal membrane oxygenation center. PATIENTS: Four hundred twenty-four individuals requiring extracorporeal membrane oxygenation support and systemically anticoagulated with either unfractionated heparin (223 adult and 65 pediatric patients) or bivalirudin (110 adult and 24 pediatric patients) were included. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Digital data abstraction was used to retrospectively collect patient details. The majority of both groups were cannulated centrally (67%), and the extracorporeal membrane oxygenation type was predominantly venoarterial (84%). The adult bivalirudin group had a greater occurrence of heparin-induced thrombocytopenia (12% vs 1%; p < 0.01) and was more likely to require postcardiotomy extracorporeal membrane oxygenation (36% vs 55%; p < 0.01). There were no statistical differences between the groups in regards to age, sex, and extracorporeal membrane oxygenation initiation location. The main finding was a reduced mortality in the adult bivalirudin group (odds ratio, 0.39; p < 0.01), whereas no difference was noted in the pediatric group. A significant reduction in the composite transfusion requirement in the first 24 hours was noted in the pediatric bivaluridin group with an odds ratio of 0.28 (p = 0.02). Groups did not differ in regard to laboratories per day, anticoagulant dose adjustments, or ischemic complications. CONCLUSIONS: When compared with heparin-based systemic anticoagulation, bivalirudin demonstrated feasibility and safety as established by the absence of increases in identifiable adverse outcomes while manifesting substantial improvements in hospital mortality in adult patients. Further studies are necessary to corroborate these findings and further elucidate the role of bivalirudin during extracorporeal membrane oxygenation support.

Desarrollo tecnológico del inyectable heparina sódica 5.000 UI/mL en solución / Technological development of sodium heparin injection in solution of 5.000 IU/mL

OBJETIVO: desarrollar una nueva formulación del inyectable en solución heparina sódica 5.000 UI/mL MÉTODOS: se ensayaron tres variantes de formulaciones y fueron preparados, de cada una, tres lotes a escala de laboratorio. Se realizó el escalado a tres lotes pilotos con la comprobación de la estabilidad durante 12 meses de vida de estante y 6 meses acelerados. RESULTADOS: la formulación compuesta por heparina sódica (5.000 UI/mL), clorobutanol como preservo, dos tampones (fosfato de sodio monobásico/fosfato de sodio dibásico) y agua para inyección, como vehículo; en bulbos 6R, transparentes e incoloros, cumplió con los requisitos de calidad. La potencia biológica y el control del pH resultaron estables en los tres lotes preparados a escala de laboratorio. CONCLUSIONES: los resultados obtenidos en estos últimos demostraron la factibilidad del desarrollo tecnológico de este medicamento, cumpliendo con las características de calidad de los inyectables

OBJECTIVE: Developing a new formulation of heparin sodium injection in solution of 5.000 IU/mL. METHODS: Three variants of formulations were tested and three batches were prepared at laboratory scale. Three pilot batches were also scaled up with stability checking for 12 months of shelf life and 6 months accelerated. RESULTS: The formulation composed of heparin sodium (5.000 IU/mL), chlorobutanol as preserve, two buffers (monobasic sodium phosphate/dibasic sodium phosphate) and water for injection, as a vehicle; 6R bulbs, transparent and colorless, met the quality requirements. Biological potency and pH control were stable in the three batches prepared at laboratory scale. CONCLUSIONS: The results obtained in the latter demonstrated the feasibility of the technological development of this medicine, fulfilling the quality characteristics of the injectables

Tools for the Quality Control of Pharmaceutical Heparin.

Heparin is a vital pharmaceutical anticoagulant drug and remains one of the few naturally sourced pharmaceutical agents used clinically. Heparin possesses a structural order with up to four levels of complexity. These levels are subject to change based on the animal or even tissue sources that they are extracted from, while higher levels are believed to be entirely dynamic and a product of their surrounding environments, including bound proteins and associated cations. In 2008, heparin sources were subject to a major contamination with a deadly compound-an over-sulphated chondroitin sulphate polysaccharide-that resulted in excess of 100 deaths within North America alone. In consideration of this, an arsenal of methods to screen for heparin contamination have been applied, based primarily on the detection of over-sulphated chondroitin sulphate. The targeted nature of these screening methods, for this specific contaminant, may leave contamination by other entities poorly protected against, but novel approaches, including library-based chemometric analysis in concert with a variety of spectroscopic methods, could be of great importance in combating future, potential threats.

Revisión de dosieres de heparina y enoxaparina: Incumplimiento de la normativa de Costa Rica para el registro sanitario de biosimilares farmacéuticos / Heparin and enoxaparin dossiers review: Non-compliance of the Costa Rican regulation for the sanitary registration of pharmaceutical biosimilars

Objetivo: Determinar los aspectos esenciales de la reglamentación de Costa Rica referente al registro sanitario de biosimilares y compararlos con la información brindada en los dosieres de laboratorios fabricantes de heparina y enoxaparina. Materiales y métodos: Se examinó el Reglamento de Inscripción y Control de Medicamentos Biológicos: RTCR 440:2010. Luego, se solicitaron los dosieres enviados por los laboratorios fabricantes y se comparó su información con respecto a los datos solicitados por el reglamento anterior. Finalmente, se evaluó la importancia de la información solicitada. Resultados: El RTCR 440:2010 solicita información química, farmacéutica y biológica del producto farmacéutico terminado, resultados sobre seguridad y eficacia, datos administrativos y documentación legal. Para los biosimilares, se debe presentar el ejercicio de biosimilitud y un plan de farmacovigilancia. Esta información no está presente en su totalidad en los dosieres revisados. Conclusiones: Los productos revisados no cumplen con los requisitos solicitados por el reglamento costarricense en lo que respecta al ejercicio de biosimilitud. Por ende, no fueron presentados para el trámite de sus registros sanitarios ante el Ministerio de Salud de Costa Rica

Objective: To determine the essential aspects of the Costa Rican regulation concerning the sanitary registration of biosimilars and to compare them with the information provided in the dossiers of laboratories manufacturing heparin and enoxaparin. Methodology: The regulation for the Registration and Control of Biological Drugs: RTCR 440: 2010 was reviewed. Subsequently, the dossiers sent by the manufacturers were requested, and their information was compared with the data requested by the previous regulation. Finally, the importance of this information was evaluated. Results: The national regulations require chemical, pharmaceutical and biological information on the finished pharmaceutical product, results on safety and efficacy, administrative data and legal documentation. For biosimilars, the biosimilitude exercise and a pharmacovigilance plan must be presented. This information is not available in its entirety in the reviewed dossiers. Conclusions: The products reviewed do not meet the requirements of the Costa Rican regulations regarding the biosimilitude exercise. Therefore, they were not submitted for their drugs' applications before the Ministry of Health of Costa Rica

The Society of Thoracic Surgeons, The Society of Cardiovascular Anesthesiologists, and The American Society of ExtraCorporeal Technology: Clinical Practice Guidelines-Anticoagulation During Cardiopulmonary Bypass.

Despite more than a half century of "safe" cardiopulmonary bypass (CPB), the evidence base surrounding the conduct of anticoagulation therapy for CPB has not been organized into a succinct guideline. For this and other reasons, there is enormous practice variability relating to the use and dosing of heparin, monitoring heparin anticoagulation, reversal of anticoagulation, and the use of alternative anticoagulants. To address this and other gaps, The Society of Thoracic Surgeons, the Society of Cardiovascular Anesthesiologists, and the American Society of Extracorporeal Technology developed an Evidence Based Workgroup. This was a group of interdisciplinary professionals gathered to summarize the evidence and create practice recommendations for various aspects of CPB. To date, anticoagulation practices in CPB have not been standardized in accordance with the evidence base. This clinical practice guideline was written with the intent to fill the evidence gap and to establish best practices in anticoagulation therapy for CPB using the available evidence. To identify relevant evidence, a systematic review was outlined and literature searches were conducted in PubMed using standardized medical subject heading (MeSH) terms from the National Library of Medicine list of search terms. Search dates were inclusive of January 2000 to December 2015. The search yielded 833 abstracts, which were reviewed by two independent reviewers. Once accepted into the full manuscript review stage, two members of the writing group evaluated each of 286 full papers for inclusion eligibility into the guideline document. Ninety-six manuscripts were included in the final review. In addition, 17 manuscripts published before 2000 were included to provide method, context, or additional supporting evidence for the recommendations as these papers were considered sentinel publications. Members of the writing group wrote and developed recommendations based on review of the articles obtained and achieved more than two thirds agreement on each recommendation. The quality of information for a given recommendation allowed assessment of the level of evidence as recommended by the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. Recommendations were written in the three following areas: (1) heparin dosing and monitoring for initiation and maintenance of CPB; (2) heparin contraindications and heparin alternatives; and (3) reversal of anticoagulation during cardiac operations. It is hoped that this guideline will serve as a resource and will stimulate investigators to conduct more research and to expand on the evidence base on the topic of anticoagulation therapy for CPB.

Novel method for the determination of average molecular weight of natural polymers based on 2D DOSY NMR and chemometrics: Example of heparin.

Apart from the characterization of impurities, the full characterization of heparin and low molecular weight heparin (LMWH) also requires the determination of average molecular weight, which is closely related to the pharmaceutical properties of anticoagulant drugs. To determine average molecular weight of these animal-derived polymer products, partial least squares regression (PLS) was utilized for modelling of diffused-ordered spectroscopy NMR data (DOSY) of a representative set of heparin (n=32) and LMWH (n=30) samples. The same sets of samples were measured by gel permeation chromatography (GPC) to obtain reference data. The application of PLS to the data led to calibration models with root mean square error of prediction of 498Da and 179Da for heparin and LMWH, respectively. The average coefficients of variation (CVs) did not exceed 2.1% excluding sample preparation (by successive measuring one solution, n=5) and 2.5% including sample preparation (by preparing and analyzing separate samples, n=5). An advantage of the method is that the sample after standard 1D NMR characterization can be used for the molecular weight determination without further manipulation. The accuracy of multivariate models is better than the previous results for other matrices employing internal standards. Therefore, DOSY experiment is recommended to be employed for the calculation of molecular weight of heparin products as a complementary measurement to standard 1D NMR quality control. The method can be easily transferred to other matrices as well.

Combining NMR Spectroscopy and Chemometrics to Monitor Structural Features of Crude Hep-arin.

Because of the complexity and global nature of the heparin supply chain, the control of heparin quality during manufacturing steps is essential to ensure the safety of the final active pharmaceutical ingredient (API). For this reason, there is a need to develop consistent analytical methods able to assess the quality of heparin early in production (i.e., as the crude heparin before it is purified to API under cGMP conditions). Although a number of analytical techniques have been applied to characterize heparin APIs, few of them have been applied for crude heparin structure and composition analyses. Here, to address this issue, NMR spectroscopy and chemometrics were applied to characterize 88 crude heparin samples. The samples were also analyzed by strong anion exchange HPLC (SAX-HPLC) as an orthogonal check of the purity levels of the crudes analyzed by NMR. The HPLC data showed that the chemometric analysis of the NMR data differentiated the samples based on their purity. These orthogonal approaches differentiated samples according their glycosaminoglycan (GAG) composition and their mono and disaccharide composition and structure for each GAG family (e.g., heparin/heparan, dermatan sulfate, and chondroitin sulfate A). Moreover, quantitative HSQC and multivariate analysis (PCA) were used to distinguish between crude heparin of different animal and tissue sources.

The US regulatory and pharmacopeia response to the global heparin contamination crisis.

The contamination of the widely used lifesaving anticoagulant drug heparin in 2007 has drawn renewed attention to the challenges that are associated with the characterization, quality control and standardization of complex biological medicines from natural sources. Heparin is a linear, highly sulfated polysaccharide consisting of alternating glucosamine and uronic acid monosaccharide residues. Heparin has been used successfully as an injectable antithrombotic medicine since the 1930s, and its isolation from animal sources (primarily porcine intestine) as well as its manufacturing processes have not changed substantially since its introduction. The 2007 heparin contamination crisis resulted in several deaths in the United States and hundreds of adverse reactions worldwide, revealing the vulnerability of a complex global supply chain to sophisticated adulteration. This Perspective discusses how the US Food and Drug Administration (FDA), the United States Pharmacopeial Convention (USP) and international stakeholders collaborated to redefine quality expectations for heparin, thus making an important natural product better controlled and less susceptible to economically motivated adulteration.

Analysis of Heparins Derived From Bovine Tissues and Comparison to Porcine Intestinal Heparins.

Heparin is a widely used clinical anticoagulant. It is also a linear glycosaminoglycan with an average mass between 10 and 20 kDa and is primarily made up of trisulfated disaccharides comprised of 1,4-linked iduronic acid and glucosamine residues containing some glucuronic acid residues. Heparin is biosynthesized in the Golgi of mast cells commonly found in the liver, intestines, and lungs. Pharmaceutical heparin currently used in the United States is primarily extracted from porcine intestines. Other sources of heparin including bovine intestine and bovine lung are being examined as potential substitutes for porcine intestinal heparin. These additional sources are intended to serve to diversify the heparin supply, making this lifesaving drug more secure. The current study examines bovine heparins prepared from both intestines and lung and compares these to porcine intestinal heparin. The structural properties of these heparins are examined using nuclear magnetic resonance, gel permeation chromatography, and disaccharide analysis of heparinase-catalyzed depolymerized heparin. The in vitro functional activities of these heparins have also been determined. The goal of this study is to establish the structural and functional similarities and potential differences between bovine and porcine heparins. Porcine and bovine heparins have structural and compositional similarities and differences.

Evaluation of a Heparin-Calibrated Antifactor Xa Assay for Measuring the Anticoagulant Effect of Oral Direct Xa Inhibitors.

The introduction of oral direct anti-Xa anticoagulants apixaban and rivaroxaban has significantly impacted the treatment and prevention of thromboembolic disease. Clinical scenarios exist in which a quantitative assessment for degree of anticoagulation due to these agents would aid management. The purpose of this work was to evaluate the chromogenic antifactor Xa assay calibrated with heparin standards at our institution for assessment of intensity of anticoagulation with rivaroxaban or apixaban in addition to its current use for unfractionated heparin or low-molecular-weight heparin. We also aimed to propose expected steady state peak and trough antifactor Xa activities for these agents based upon dosing regimens approved for nonvalvular atrial fibrillation. Antifactor Xa activity correlated very strongly with apixaban and rivaroxaban concentration in both spiked samples and treated patient plasma samples (r (2) = .99, P < .001). This correlation was observed over a broad range (20-500 ng/mL) of drug concentrations, as sample dilution with pooled normal plasma significantly extended the range of quantitative assessment. Based on drug concentrations previously published in pharmacokinetic studies, the expected steady state peak and trough antifactor Xa activity ranges for apixaban are 1.80 to 2.20 IU/mL and 0.70 to 1.10 IU/mL, respectively. For rivaroxaban, these ranges are 3.80 to 6.20 IU/mL and 0.60 to 1.00 IU/mL, respectively. In conclusion, our findings demonstrate that heparin-calibrated antifactor Xa activity correlates strongly with apixaban and rivaroxaban concentration. The dilution of samples allowed for this correlation to be extended over the majority of on-therapy drug concentrations.

Combining 1H NMR spectroscopy and multivariate regression techniques to quantitatively determine falsification of porcine heparin with bovine species.

(1)H NMR spectroscopy was used to distinguish pure porcine heparin and porcine heparin blended with bovine species and to quantify the degree of such adulteration. For multivariate modelling several statistical methods such as partial least squares regression (PLS), ridge regression (RR), stepwise regression with variable selection (SR), stepwise principal component regression (SPCR) were utilized for modeling NMR data of in-house prepared blends (n=80). The models were exhaustively validated using independent test and prediction sets. PLS and RR showed the best performance for estimating heparin falsification regarding its animal origin with the limit of detection (LOD) and root mean square error of validation (RMSEV) below 2% w/w and 1% w/w, respectively. Reproducibility expressed in coefficients of variation was estimated to be below 10% starting from approximately 5% w/w of bovine adulteration. Acceptable calibration model was obtained by SPCR, by its application range was limited, whereas SR is least recommended for heparin matrix. The developed method was found to be applicable also to heparinoid matrix (not purified heparin). In this case root mean square of prediction (RMSEP) and LOD were approximately 7% w/w and 8% w/w, respectively. The simple and cheap NMR method is recommended for screening of heparin animal origin in parallel with official NMR test of heparin authenticity and purity.

Specific anti-IIa activity is a key indicator of safety and efficacy in validation of biosimilarity of unfractioned heparin preparations.

We compared anti-IIa activity of a heparin analogue and a reference product was carried out to confirm their biosimilarity. The experiment was based on the method of estimation of anti-IIa activity of a commercial sodium heparin preparation according to United States Pharmacopoeia. High similarity of the two medicinal heparin preparations by this parameter is shown. The method is recommended for the use in comparability studies.

Protamine requirements in cardiac surgery: effect of changes in the heparin reference standard.

OBJECTIVE: UFH (unfractionated heparin) and protamine are integral to cardiac surgery, and inappropriate dosing can predispose to coagulopathy and hemorrhage. The FDA (Food and Drug Administration) recently has instituted changes to UFH formulation and it is not known if this has influenced its susceptibility to neutralization by protamine. Hence, the authors sought to compare 2 commercial preparations of UFH (old and new) with regard to their neutralization by protamine in patients undergoing cardiopulmonary bypass (CPB). DESIGN: Prospective, observational, cohort study. SETTING: Tertiary care university hospital and associated research laboratory PARTICIPANTS: Twenty adult patients undergoing elective cardiac surgery with CPB. INTERVENTIONS: Blood samples were drawn preinduction, prior to, and 5 and 30 minutes following protamine, and 0 and 2 hours after ICU admission. Protamine titration assays were conducted in vitro on samples drawn prior to and following protamine administration. Anti-IIa and anti-Xa activity were assayed in all samples. RESULTS: Anti-IIa and anti-Xa activity were detected ubiquitously at all time points following CPB, and there were no differences in susceptibility to protamine neutralization between the 2 groups. In vitro protamine titration studies revealed that anti-IIa was more resistant to protamine neutralization compared to anti-Xa activity. CONCLUSIONS: The 'old' and 'new' formulations of UFH evaluated in this study were similar in their susceptibility to protamine neutralization. Circulating UFH is detected as early as 5 minutes after protamine administration and anti-IIa is more resistant to protamine neutralization as compared to anti-Xa activity. Further studies are required to quantify the precise dose of protamine following CPB.

Collaborative study for the recalibration of Ph. Eur. Heparin sodium BRP batch 3 for chromogenic potency assays.

Following the heparin adulteration crisis, the European Pharmacopoeia (Ph. Eur.) Group of Experts on Biologicals (Group 6) considered a revision of the general chapter 2.7.5. Assay of heparin with regard to the assay of the anticoagulant activity of heparin in order to replace the clotting method with more specific chromogenic methods for anti-IIa and anti-Xa activities. An international collaborative study was carried out in 3 phases under the aegis of the Biological Standardisation Programme (BSP) of the Council of Europe and the European Commission in order to recalibrate Heparin sodium Biological Reference Preparation (BRP) batch 3 for these new assays. Phase 1 confirmed the feasibility of the project, but also indicated that the composition of the buffers affects the assay results, thereby highlighting the importance of using common assay procedures. Phase 2 consisted of a collaborative study involving 15 laboratories to calibrate the anti-IIa and anti-Xa activities of Heparin sodium BRP batch 3. The collaborative study confirmed that Heparin sodium BRP batch 3 is suitable for use as a reference preparation in the proposed chromogenic assays for unfractionated heparin. It also showed that the currently defined acceptance limits (90 % to 111 %) can be maintained in the revised Ph. Eur. texts. Phase 3 of the study collected data on the impact of the new unitage on the release of products marketed in Europe. The data from 5 manufacturers, who each reported results from both the clotting and chromogenic assays for a total of 23 batches, indicated that the replacement of the pharmacopoeial method is unlikely to cause batch release issues. Based on the results of this study, the Ph. Eur. Commission assigned Heparin sodium BRP batch 3 with a potency of 1000 IU/vial for both anti-IIa and anti-Xa activities in the chromogenic assays.

Has the new USP assay for heparin affected dosage for patients undergoing cardiopulmonary bypass?

In October 2009, the U.S. Pharmacopoeia (USP) changed the monograph for heparin to bring USP units in line with international units for heparin. The result was a 10% decrease in potency as measured by in vitro laboratory tests. This decrease led to questions regarding dosing guidelines. There existed a need for an in vivo study to determine the practical changes that may need to be implemented in regard to heparin administration for cardiopulmonary bypass in the clinical setting. A retrospective study was conducted to determine the heparin dose administered and the corresponding effect on patients undergoing coronary artery bypass grafting surgery using cardiopulmonary bypass. The study compared the heparin dose requirements and activated clotting time (ACT) results using the heparin before and after the USP changes. An analysis of the data was performed to determine the increased heparin dose required to achieve the same effect as before the USP change. This new heparin dosing protocol was instituted at Concord Hospital, Concord, NH. A prospective study was then preformed to verify the effects of the dosing change. In the new heparin group, the postheparin ACT fell by 9.1% (p = .028) and the patients achieving an ACT > 479 seconds fell by 12.8% as compared with the old heparin group. After adjustment of the loading dose calculation for heparin, the prospective study demonstrated the postheparin ACT (p = .684) and the percentage of patients achieving an ACT > 479 seconds (p = 1.000) to be similar to the values obtained before the USP change. An increase of the loading dose of approximately 12% is needed to achieve the patient effects seen before the UPS change.

Electrophoresis for the analysis of heparin purity and quality.

The adulteration of raw heparin with oversulfated chondroitin sulfate (OSCS) in 2007-2008 produced a global crisis resulting in extensive revisions to the pharmacopeia monographs and prompting the FDA to recommend the development of additional methods for the analysis of heparin purity. As a consequence, a wide variety of innovative analytical approaches have been developed for the quality assurance and purity of unfractionated and low-molecular-weight heparins. This review discusses recent developments in electrophoresis techniques available for the sensitive separation, detection, and partial structural characterization of heparin contaminants. In particular, this review summarizes recent publications on heparin quality and related impurity analysis using electrophoretic separations such as capillary electrophoresis (CE) of intact polysaccharides and hexosamines derived from their acidic hydrolysis, and polyacrylamide gel electrophoresis (PAGE) for the separation of heparin samples without and in the presence of its relatively specific depolymerization process with nitrous acid treatment.

Validation of quantitative polymerase chain reaction methodology for monitoring DNA as a surrogate marker for species material contamination in porcine heparin.

Heparin is a widely used intravenous anticoagulant comprising of a very complex mixture of glycosaminoglycan chains, mainly derived from porcine intestinal mucosa. The species of origin and the absence of contaminants from other species are important determinants of the different physicochemical characteristics of heparin. They also determine the potential for introducing infectious and adventitious agents into heparin batches destined for medicinal use. We perform routine quantitative polymerase chain reaction (Q-PCR) release tests to confirm the quality of all crude heparin batches, including those used for the manufacture of enoxaparin sodium. Here we further demonstrate that the assessment of the DNA content in crude heparin is a good surrogate marker of contamination at the mucosa level. After spiking porcine mucosa with ovine mucosa and processing this material to form crude heparin, we were able to observe similar ratios of species-specific DNA in both the starting and end products. Experiments performed with 3,000 and 1,500 ppm contamination found these concentrations to be well above the detection limit for our assay of heparin batches. Additionally this Q-PCR method can be used to detect contamination in mucosa, thus providing a tool capable of monitoring for contaminants throughout the crude heparin manufacturing process. Q-PCR analysis of industrial crude heparin samples has confirmed over time the value of this method to assess the pure porcine origin of heparin.

Mantenimiento y cuidado de catéteres intravasculares. La importancia de la heparinización / No disponible

No disponible

History of heparin.

The history of heparin is described from its initial discovery in 1916 to recent developments in knowledge of its mechanism of action and clinical use. Commercial production started soon after its discovery, in the 1920s, and improved purification methods led to animal studies and the first clinical trials in the 1930s. Research into heparin's chemical structure proved difficult, with uncertainty about the uronic acid moiety and the N-acetyl content, but the structure of the basic disaccharide unit was established by the 1960s, though knowledge of the heterogeneity and fine structure of heparin chains continued to accumulate over the next 20 years. In 1976, it was found that only one third of heparin chains bound with high affinity to antithrombin, and subsequent studies identified a unique pentasaccharide sequence, which was essential for antithrombin binding and anticoagulant activity - this pentasaccharide was synthesised in 1983. Clinical usage of heparin continued to increase and two major developments were the use of low- dose heparin for prevention of deep vein thrombosis and pulmonary embolism, and the development of low-molecular-weight heparin as a separate drug.