Screening of anionic-modified polymers in terms of stability, disintegration, and swelling behavior

Abstract

This study aimed to screen the stability, disintegration, and swelling behavior of chemically modified anionic polymers. Investigated polymers were well-known and widely used staples of the pharmaceutical and medical field, namely, alginate (AL), carboxymethyl cellulose (CMC), polycarbophil (PC), and hyaluronic acid (HA). On the basis of amide bond formation between the carboxylic acid moieties of anionic polymers and the primary amino group of the modification ligand cysteine (CYS), the modified polymers were obtained. Unmodified polymers served as controls throughout all studies. With the Ellman's assay, modification degrees were determined of synthesized polymeric excipients. Stability assay in terms of erosion study at physiological conditions were performed. Moreover, water uptake of compressed polymeric discs were evaluated and further disintegration studies according to the USP were carried out to define the potential ranking. Results ranking figured out PCCYS > CMCCYS > HACYS > ALCYS in terms of water uptake capacity compared to respective controls. Cell viability assays on Caco-2 cell line as well as on RPMI 2650 (ATTC CCL30) proved modification not being harmful to those. Due to the results of this study, an intense screening of prominent anionic polymer derivate was performed in order to help the pharmaceutical research for the best choice of polymeric excipients for developments of controlled drug release systems.

Comparative mucoadhesive study of hyaluronic acid‐based conjugates on different mucosae

“…Anchored HA yielded a 2.7‐, 2.6‐, and 1.25‐fold improvement in swelling behavior in comparison to unmodified HA on nasal, buccal, and vaginal mucosa, respectively. Furthermore as found HA–SH exhibited more pronounced water uptake potential compared to unmodified HA on all types of mucosae which is in good correlation with already established screenings of the proficiency to uptake water with a series of anionic sulfhydryl‐anchored polymers . Declarations could be given caused by the covalent attachment of cysteine.…”

“…Tissues were brought to dryness and histological images were recorded using ibidi mounting medium in connection with a Zeiss Axiovert 40 CFL inverted, digital light microscope (Carl Zeiss AG, Jena, Germany). The microscope was equipped with an InfinityX‐32C, 32‐megapixal CCD digital video camera (Lumenera Corporation, Ottawa, Canada) …”