ABSTRACT
Low-molecular-weight heparin represent a significant advancement in anticoagulant therapy with enoxaparin being a prominent example obtained exclusively through the fragmentation of porcine intestinal heparin. However, escalating demand and limited resources have raised concerns about enoxaparin supplementation. The current challenge involves exploring alternative heparin sources for large-scale enoxaparin production with bovine intestinal heparin emerging as a promising option. Our study demonstrates that enoxaparin derived from the available bovine heparin preparation differs significantly from the reference compound. Yet, the implementation of a straightforward purification step yields a preparation termed "high-anticoagulant bovine heparin". Fragmentation of this purified product through ß-elimination produces enoxaparin akin to the standard from a porcine origin. To ensure physicochemical similarity, we employed various spectroscopic, enzymatic, and chromatographic tests to compare the new bovine-derived enoxaparin with the original porcine compound. Biological activity was confirmed through in vitro coagulation assays and assessments using an animal model of venous thrombosis. Our study affirms that the ß-elimination reaction cleaves the bovine heparin chain without preferential breaks in regions with different sulfation patterns. Additionally, we scrutinized decasaccharides purified from enoxaparin preparations, providing a comprehensive demonstration of the similarity between products obtained from porcine and bovine heparin. In summary, our findings indicate that an enoxaparin equivalent to the original porcine-derived product can be derived from bovine heparin, given that the starting material undergoes a simple purification step.
ABSTRACT
Pharmaceutical heparins from different manufacturers may present heterogeneities due to particular extraction and purification procedures or even variations in the raw material manipulation. Heparins obtained from different tissues also differ in their structure and activity. Nevertheless, there is an increased demand for more accurate assessments to ensure the similarities of pharmaceutical heparins. We propose an approach to accurately assess the similarity of these pharmaceutical preparations based on well-defined criteria, which are verified with a variety of refined analytical methods. We evaluate six commercial batches from two different manufacturers which were formulated with Brazilian or Chinese active pharmaceutical ingredients. Biochemical and spectroscopic methods and analysis based on digestion with heparinases were employed to evaluate the purity and structure of the heparins. Specific assays were employed to evaluate the biological activity. We observed minor but significant differences between the constitutive units of the heparins from these two manufacturers, such as the content of N-acetylated α-glucosamine. They also have minor differences in their molecular masses. These physicochemical differences have no impact on the anticoagulant activity but can indicate particularities on their manufacturing processes. The protocol we propose here for analyzing the similarity of unfractionated heparins is analogous to those successfully employed to compare low-molecular-weight heparins.