The cytisine-enriched poly(3-hydroxybutyrate) fibers for sustained-release dosage form

The polymeric cytisine-enriched fibers based on poly(3-hydroxybutyrate) were obtained using electrospinning method. The biocompatibility study, advanced thermal analysis and release of cytisine from the poly(3-hydroxybutyrate) fibers were carried out. The nanofibers' morphology was evaluated by scanning electron mi-croscopy. The formation and description of phases during the thermal processes of fibers by the advanced thermal analysis were examined. The new quantitative thermal analysis of polymeric fibers with cytisine phases based on vibrational, solid and liquid heat capacities was presented. The apparent heat capacity of fibers was measured using the standard differential scanning calorimetry. The quantitative analysis allowed for the study of the glass transition and melting/crystallization process. The mobile amorphous fraction, degree of crystallinity and rigid amorphous fraction were determined depending on the thermal history of semicrystalline polymeric fibers. Furthermore, the cytisine dissolution behaviour was studied. It was observed that the kinetic of the release from polymeric nanofiber is delayed than for the marketed product. The immunosafety of the tested polymeric nanofibers with cytisine was confirmed by the Food and Drug Agency Guidance as well as the European Med-icines Agency. The polymeric matrix with cytisine seems to be a promising candidate for the prolonged release formulation.

Automated summary

Polymeric cytisine-enriched fibers were prepared using electrospinning method based on poly(3-hydroxybutyrate). The biocompatibility, thermal analysis, and cytisine release from the fibers were examined. The morphology of the nanofibers was evaluated using scanning electron microscopy. Advanced thermal analysis was conducted to study the phases and thermal processes of the fibers. Quantitative thermal analysis revealed the heat capacities and allowed for the study of the glass transition and melting/crystallization process of the polymeric fibers. The dissolution behavior of cytisine was also investigated, showing delayed release from the polymeric nanofibers compared to the marketed product. The immunosafety of the tested polymeric nanofibers with cytisine was confirmed by regulatory agencies. The polymeric matrix with cytisine holds promise as a prolonged release formulation.