| Popis: |
Low molecular weight chitosan (LMWC) is a semi synthetic biopolymer with potential uses as a pharmaceutical excipient, though, consistent and reliable grades of pure LMWC are scarce. Credible and competent preparation and characterization methods are, therefore, of utmost importance to specialized laboratories. Although acid hydrolysis of chitosan is already known, existing protocols produce oligomer mixtures of high polydispersity and fail to predict the ensuing molecular weights. We, herein, optimize a mild acid-catalyzed depolymerization of high molecular weight chitosan (HMWC) of 100kDa and 93% degree of deacetylation, and develop a standardized protocol that enables the predetermination of resultant molecular weight and re-acetylation in the ranges of 1.4-28.1 kDa and 55.1-81.1%, respectively. Molecular weight measurements were extracted and verified based on dynamic viscosity readings and dynamic light scattering. Degree of deacetylation was calculated by H1 NMR. These protocols were found to be efficient, time and cost-effective, reproducible, and gave LMWC with the desired quality and yield for research purposes. |
