Characterization of a novel, co-processed bio-based polymer, and its effect on mucoadhesive strength

In this study, a biological macromolecule obtained from seeds of Manilkara zapota was co-processed with hypromellose (cop-MPH)/sodium carboxymethylcellulose (cop-MPN)/polyvinylpyrrolidone (cop-MPP) in a 1:1 ratio and characterized for powder and mucoadhesive properties. The semi-crystalline nature of co-processed excipients and physical interaction between the component molecules were confirmed by X-ray diffraction and infrared spectroscopy analysis. The morphological study by scanning electron and atomic force microscopy showed spherical and polygonal-shaped particles with predominant smooth surfaces. Thermogravimetric analysis revealed thermal stability to a temperature of 200 °C followed by depolymerization. Zeta potential measurements showed that cop-MPP was anionic, whereas cop-MPH and MPN were non-ionic. Texture analysis revealed that work of adhesion (mN·s) for both cop-MPH (390 ± 0.0018) and MPN (304 ± 0.0024) enhanced the mucoadhesion compared with the un-processed hypromellose (300 ± 0.0019) and sodium carboxymethylcellulose (280 ± 0.0012), whereas cop-MPP (240 ± 0.0028) showed mucoadhesion similar to un-processed polyvinylpyrrolidone (250 ± 0.0022). In addition, the swelling studies showed enhancement in water absorbance for all co-processed excipients. Cytotoxicity against human cells revealed >99% of cell viability. These findings demonstrate that the co-processed biological macromolecule extracted from M. zapota seed could be further explored as an effective alternative drug delivery excipient for pharmaceutical applications.