Introduction: Bovine mucosal heparins (BMH) are currently being developed for re-introduction for both medical and surgical indications. BMH active pharmaceutical ingredient (API) exhibits a somewhat weaker USP potency when compared to PMHs. We hypothesized that when dosages are normalized based on the USP reference heparin, BMH will exhibit comparable in vitro and in vivo effects to those produced by PMH. Therefore, studies were developed to compare the APIs of bovine and porcine heparin.Materials and Methods: API versions of PMH were obtained from Celsus Laboratories (Franklin, OH) and Medefil (Glen Ellen, IL). API versions of BMH were obtained from Kin Master (Passo Fundo, Brazil). Each of these heparins was assayed for their molecular weight profile, AT affinity, USP potency, and anticoagulant/antiprotease profiles using standard laboratory methods. In vitro protamine neutralization studies were carried out. Antithrombotic and hemorrhagic effects were measured in rats and pharmacodynamic profiles were assessed in primates.Results: Size exclusion chromatography demonstrated that the mean molecular weight of BMH was ~15% higher than that of PMH (BMH: 20.1 ± 0.8 kDa and PMH: 17.5 ± 0.7 kDa). BMH exhibited an anti-Xa potency of 130 U/mg while PMH had an anti-Xa potency of 185 U/mg. In the anticoagulant and antiprotease assays, the BMH exhibited lower functionality which was proportional to USP potency. When the BMH was compared with PMH at potency adjusted concentrations, it showed identical concentration-response curves in the aPTT and anti-protease assays. However, in the protamine neutralization studies, BMH required slightly higher amounts of protamine in contrast to PMH. BMH and PMH administered to rats at equivalent anti-Xa unit dosages resulted in comparable antithrombotic activity and prolongation of bleeding time. Similar pharmacodynamic profiles were observed in primates when BMH and PMH were dosed on an anti-Xa U/kg basis.Conclusion: BMH, when used at comparable anti-Xa unit levels, is comparable to PMH, however, it requires proportionally higher amount of protamine due to the increased mass for adjusting to higher potency. Additional studies on the structural characterization, interactions with PF4 and in vivo neutralization studies are ongoing.

Stevens-Johnson Syndrome (SJS) and toxic epidermal necrolysis (TEN) are Severe Cutaneous Adverse Reactions (SCARS) characterized by fever and mucocutaneous lesions leading to necrosis and sloughing of the epidermis. Conjunctival lesions are reported in 85% of patients. The pathogenesis of SJS/TEN/SCARS is not completely understood. It is hypothesized that IL-13, IL-15 and Granulysin expressed in plasma and skin may play a role. We measured the circulating levels of these cytokines in the plasma using ELISA and their expression in the skin using immunofluorescence microscopy. A total of 12 SJS/TEN skin biopsy samples (8 SJS, 2 SJS/TEN overlap and 2 TEN) were analyzed. Biopsy samples from patients with Lichen Planus (an inflammatory condition of the skin and mucous membranes) served as controls. Studies were also performed in human corneal epithelial cells where expression of these cytokines were measured following a challenge with TNF-α (0, 1, 10 and 100 ng/ml). The intensity of immunofluorescence was measured Using Imaris® software. The results showed significantly increased expression of these cytokines in the skin biopsy samples as measured by the average intensities of IL-13 (6.1 x 133.0 ± 4.231 x 10^8), and Granulysin (4.2 x 123.0 ± 4.231 x 10^8) compared to Lichen planus control (3.0 x 123.0 ±1.62 x 10^5). Increased expression of IL-13 and IL-15 were noted in cell culture studies and in the plasma samples when compared to Normal Human Plasma as controls. It is concluded that IL-13, IL-15 and Granulysin play a role in the pathogenesis of SJS/TEN.

Introduction: Sulodexide represents a glycosaminoglycan derived antithrombotic agent which is clinically used for the management of vascular disorders and is pharmacologically active after both parenteral and oral administration. Similar to unfractionated heparin (UFH), this drug is derived from porcine mucosal tissue and is composed of a mixture of fast moving low molecular weight heparin (molecular weight 7.0 Kda) and dermatan sulfate (molecular weight 20 Kda). The USP anticoagulant potency of sulodexide is 92 + 4 USP units / mg in contrast to unfractionated heparin which is 200 U/mg. The purpose of this study is to compare the relative effect of sulodexide in mediating heparin induced thrombocytopenia (HIT) antibodies induced aggregation of human platelets in a standardized test system which is developed to compare the effects of heparins and related drugs. Materials and Methods: Active pharmaceutical ingredients (API versions of sulodexide), fast moving heparin and dermatan sulfate were obtained from Alfa Sigma (Bologna, Italy). API versions of UFH were obtained from Medefil, Inc (Glendale Heights, IL, USA). All agents were dissolved in saline at a stock concentration of 1 mg/ml. Working dilutions were prepared at 100, 10 and 1 mg/ml. The source of functional HIT antibody represented a frozen pool of aphresis fluid (AF) collected from five clinically confirmed heparin induced thrombocytopenia patients. The functionality of the HIT antibodies in this pool were confirmed in the platelet aggregation 14C serotonin release assay. To test the relative effects of sulodexide, its components and UFH, 175 microliter of platelet rich plasma was mixed with 50 microliter of each of AF and incubated for 3 minutes followed by the addition of 25 microliter of the test agent at a final concentration range of 0 - 100 ug/ml. Platelet aggregation responses were recorded for up to 60 minutes in terms of percent aggregation. To test the ability of each of the agents for relative PF4 release from the whole blood, blood samples from healthy donors (n=20) were incubated with these agents at a concentration of 100 ug/ml for 60 minutes. The released PF4 in plasma was measured by using a commercially available ELISA method. Results: All results were compiled in terms of percent aggregation of platelets and represented as mean + standard deviation (Table 1). UFH produced a concentration dependent aggregation from 0 - 10 ug/ml reaching a peak aggregation of 61 + 12%. Sulodexide produced a relatively weaker aggregatory response and produced mild aggregation in the same concentration range exhibiting 30 + 7 platelet aggregation at 10 ug/ml. The fast moving heparin component of sulodexide produced a concentration dependent response comparable to heparin reaching a maximum aggregation of 66 + 10% at 10 ug/ml. The dermatan sulfate component did not produce any significant aggregation of platelets and no concentration dependence was observed. All agents showed a much lower aggregation at 100 ug/ml. The relative release of PF4 from the whole blood was the highest at UFH (310 + 40 ng/ml), whereas in sulodexide supplemented samples it was much lower (140 + 18 ng/ml). The fast moving heparin showed comparable results to heparin (330 + 46 ng/ml), dermatan sulfate exhibited milder release of PF4 (58 + 11 ng/ml) which was comparable to saline (67 + 14 ng/ml). Discussion: These results clearly show that in comparison to heparin sulodexide produces a relatively milder response in the functional HIT antibody screening studies. However, the fast moving heparin component of sulodexide produces comparable responses to UFH whereas dermatan sulfate has much weaker aggregate response. Similarly in the PF4 release studies while UFH and fast moving heparin produced high release of PF4, sulodexide produces relatively lower levels of PF4. The dermatan sulfate was much weaker in mobilizing PF4 from the platelets. Taken together these results are consistent to the clinical observations where sulodexide is shown to be much weaker in producing HIT responses. Table 1 Disclosures No relevant conflicts of interest to declare.

Introduction: Sulodexide represents a mixture of fast-moving heparin (FMH) and dermatan sulfate (DS) and has been used for the management of venous diseases such as DVT and related disorders. The purpose of this study is to compare sulodexide and its components with unfractionated heparin (UFH) to determine its suitability for the indications in which UFH is used. Materials and Method: Active pharmaceutical ingredients (API) versions of sulodexide, FMH and DS were obtained from Alfasigma. API versions of UFH were obtained from Medefil Inc. Normal human citrated plasma was obtained from blood bank of the Loyola University Medical Center. Each of the individual agents were supplemented in plasma at a graded concentration of 0.0-10 µg/mL. Clotting assays (PiCT, aPTT, PT and TT), anti-Xa and anti-IIa and thrombin generation studies were carried out. Results were compiled as mean ± SD of 3 individual determination. Result: In the clot based (PiCT, aPTT and TT), anti-Xa and IIa assays, both the UFH and FMH produced stronger activities in these assays followed by sulodexide. DS did not show any anticoagulant activity. In the thrombin generation assay, FMH and UFH produced comparable inhibition of thrombin generation as measured by various parameters. Sulodexide was slightly weaker in this assay, whereas DS produced relatively weaker effects. Conclusion: In comparison to sulodexide, both UFH and FMH exhibit comparable anticoagulant activity despite differences in their molecular weight. These results suggest that sulodexide can be developed as a parenteral anticoagulant for indications in which UFH is used.

Introduction: Currently, there is a shortage of porcine heparin due to limited availability of porcine mucosa and supply chain issues. Bovine heparin has been used for clinical purposes globally and is being considered for reintroduction in the U.S. On a mass basis, commercially available porcine heparins exhibit a higher potency (180-220 units/mg) than their bovine counterpart (130-150 units/mg). Therefore, at gravimetric levels, the porcine heparins exhibit stronger biochemical and pharmacological effects in comparison to bovine heparin. Since heparin is standardized in biologic units relative to the USP or EP Standard, it is hypothesized that potency equated porcine and bovine heparin will exhibit similar biologic activities in laboratory assays. The purpose of this study was to compare the biologic properties of the porcine and bovine heparin at USP potency equated levels in standardized laboratory assays used for measuring and monitoring heparins. Materials and Methods: Active pharmaceutical ingredient (API) porcine mucosal heparin (200 units/mg) of U.S. origin was obtained from Medefil Inc. (Glendale Heights, IL). Bovine heparin (140 units/mg) was obtained from KinMaster Produtos Químicos (Passo Fundo, Brazil). Whole blood Activated Clotting Time (ACT) and Thrombelastographic analyses were performed. Clot based assays such as aPTT, TT, and prothrombinase induced clotting time (PiCT) were performed using citrated human plasma supplemented with heparins up to 1 anti-Xa unit/mL. Anti-Xa and anti-IIa activities were determined using chromogenic antiprotease assays (Biophen Kits). In a purified antithrombin-supplemented system, the inhibitory effects of these agents were measured in terms of anti-Xa and anti-IIa activities and expressed as IC50 values. Thrombin generation inhibition was measured using a kinetic assay (CAT system, Diagnostica Stago, Paris, France). Protamine and platelet factor 4 neutralization profiles were investigated in plasma-based systems. The heparin induced thrombocytopenia antibody (HIT) interaction profile was assessed using platelet aggregometry. Results: Both heparins produced comparable prolongation of the ACT to a range of 200-250 seconds. The thrombelastographic profile was comparable at concentrations of 0.125 unit/mL and 2.5 units/mL. Whole blood and plasma clotting times (aPTT and TT assays) were comparable at concentrations up to 1 unit/mL. In the chromogenic anti-Xa and anti-IIa assays, the behavior of both agents was also comparable. In the purified system, the IC50 values for both agents for the anti-Xa activity ranged from 0.33-0.40 unit/mL, whereas the anti-IIa values ranged from 0.38-0.42 unit/mL; no significant differences were noted between the porcine and bovine heparins. In the thrombin generation assays, in terms of peak thrombin generation, area under the curve, and lag time, both the porcine and bovine heparins showed comparable effects. The protamine neutralization profiles of the porcine and bovine heparin exhibited variable assay dependent results. Potency adjusted bovine heparin required higher amount of protamine for the complete neutralization of the biologic effects in comparison to the porcine heparin. Similar results were obtained in the platelet factor 4 neutralization studies. In the functional HIT screening assay, both heparins exhibited a similar concentration dependent aggregation of human platelets. These results are summarized in the Table. Summary and Conclusion: These results show that at potency adjusted concentrations, porcine and bovine heparin exhibit comparable biochemical and anticoagulant responses in whole blood, plasma based, and purified biochemical assays. Most notably, both the porcine and bovine heparin produced comparable HIT antibody mediated aggregation responses. Thus, the proposed approach to standardize heparins against a common standard using a biologic assay such as the USP method is valid. These results warrant additional validation studies to reintroduce bovine heparin for clinical use. Table Disclosures Jeske: KinMaster Produtos Quimicas: Research Funding.