Assessment of Monomer Ratio of Polymeric Excipients

The properties of a polymer are determined by the identity of each monomer, but also by their proportions in it. Exting excipientss based on polymer design and manufacturing have been widely used in in vitro drug release. Excipients with different monomers have different characteristics in hygroscopicity, molecular weight (M_w) and glass transition temperature (T_g). These characteristics of materials are essential for the selection of delivery system that are suitable for patients. For example, the rheological properties of a polymer are closely related to the monomer ratio of the polymer. Therefore, the monomer ratio of the polymer is essential for the initial understanding of the product's performance. BOC Sciences has invested in basic research on polymeric excipients, and is still establishing new excipient testing methods to address our customers' different questions. We offer fast and flexible characterization services to analyze the monomer ratio of a variety of polymeric excipients.

Characterization of Monomer Ratio

In the field of analytical chemistry, NMR spectroscopy is a well-established analytical technique used to determine the molecular structure and chemical composition of samples. In the analysis of excipient materials, we use NMR methods for qualitative and quantitative analysis to monitor reactions, identify structures, and assess purity. For the accurate characterization of polymeric excipients, our scientists employ NMR techniques to analyze monomer ratios, molecular weights, ligand structure, sequencing, chain length and branching, and to determine end groups.

Assessment Process of Monomer Ratio

• Firstly, cellulose derivative is etherified by using chemical agents, and the hydroxyls are substituted by the etherifying reagent.
• After the hydrolysis process is completed, all individual monomers are separated.
• The distribution of substituents within the monomer units is identified and quantified to calculate the ratios.

Figure 1. Determination of monomer reactivity ratios and thermal properties of poly copolymers using the ¹H-NMR spectroscopy. (Abdollahi, H.; et al. 2021)

Our Advantages

• BOC Sciences focuses on the physicochemical characterization of pharmaceutical polymeric excipients to help our customers gain a deeper understanding of specific formulation formulations
• Years of pharmaceutical formulation development experience has given us the ability to obtain actual chemical excipient composition profiles beyond the limited information on a Certificate of Analysis (CoA)
• Over the past 10 years, BOC Sciences' analytical scientists have established unique, specific analytical and physicochemical methods and employed ingenious sample preparation techniques to characterize a wide range of pharmaceutical polymeric excipients
• Much knowledge has been gained about many polymeric excipients, their properties and exact composition, the differences between batches, qualities, grades and manufacturers, how to quantify their content in pharmaceuticals and how they can best be used in formulations