Evaluation of the Effect of Formulation Composition and Physicochemical Properties of Omeprazole and Bisoprolol Hemifumarate on Electrospun Nanofibers Characteristics.

Abstract

Purpose: Electrospinning enables the formation of nanofibers by elongating a polymer solution droplet in a high-voltage electrostatic field. The drug substance incorporated into nanofibrous matrix exhibits unique dissolution characteristics, modifiable by polymers selection. The physicochemical properties of the drug substance may also influence structural and functional attributes of the nanofibers. This study aimed to produce nanofibers loaded with small-molecule drugs - omeprazole (OMZ) and bisoprolol hemifumarate (BIS) to investigate how drug and polymer properties influence fiber formation and drug release. The effect of compression into minitablets on dissolution parameters was also assessed.

Methods: Ethanolic solutions of Eudragit^® RL (ERL), Eudragit^® RS (ERS), and polyvinylpyrrolidone (PVP) were mixed in 13 combinations. OMZ or BIS was dissolved in each mixture and electrospun. Selected nanofibers were compressed into minitablets. Nanofiber morphology, diameter, drug crystallinity and content uniformity were assessed. Dissolution profiles and release kinetics were evaluated for nanofibers and minitablets.

Results: Nanofibers morphology depended on the API and polymers composition. The BIS fibers were nanosized, while OMZ fibers showed heterogeneous thicknesses ranging from 0.54 µm to 5.7 µm. The drug substances were amorphous in nanofibers. OMZ formulations exhibited a sustained release except OMZ_PVP fibers, which released OMZ immediately. The BIS-loaded nanofibers demonstrated a rapid and nearly complete drug release, except for the BIS_ERL+ERS_7+3 formulation, which exhibited prolonged release. Compression of fibers into minitablets preserved the sustained drug release for both drug substances.

Conclusion: The study proves that nanofibers based on Eudragit RL/RS and PVP can be obtained by the electrospinning method. BIS properties such as good solubility, balanced hydrophobic-lipophilic nature, surface charge, and amorphous form contributed to its rapid release, unlike OMZ.