Scholarlink

Introduction <p>Oral delivery of insulin remains a major challenge due to enzymatic degradation, poor intestinal permeability, and low bioavailability. Several studies have reported the development of oral insulin delivery systems as alternatives to parenteral administration, enabling sustained oral delivery compared with injectable insulin.</p> Methodology <p>This study aimed to develop and evaluate a sustained-release polymeric nanosphere system for oral insulin delivery using a multi-component formulation strategy. Insulin-loaded nanospheres were prepared using chitosan, sodium alginate, Eudragit E, β-cyclodextrin, and folic acid, and five formulations (F1–F5) were optimised based on particle size, polydispersity index (PDI), zeta potential, and entrapment efficiency. </p> Results <p>The optimised formulation showed a mean particle size of 188.9 ± 5.1 nm, a low PDI (0.218), a high positive zeta potential (+ 56.8 ± 2.7 mV), and an entrapment efficiency of 79.84%. In vitro release studies demonstrated pH-dependent sustained release, with minimal insulin release under acidic conditions (pH 1.2) after 2 h, and near-complete release (96%) over 24 h at intestinal pH 6.8. Release kinetics followed first-order and Hixson–Crowell models, indicating diffusion- and erosion-controlled mechanisms. ATR-FTIR and DSC analyses confirmed the absence of chemical incompatibility and suggested molecular dispersion of insulin within the polymeric matrix. Morphological evaluation using optical microscopy, SEM, and ESEM revealed predominantly spherical nanospheres with well-defined structures. Circular dichroism spectroscopy showed preservation of insulin’s α-helical secondary structure after formulation and during refrigerated storage, indicating conformational stability. Physical stability studies demonstrated maintained particle characteristics for up to 45 days at 2–4 °C.</p> Conclusion <p>This multi-component nanosphere system effectively protected insulin, enabled sustained release as confirmed by HPLC, and preserved structural integrity, highlighting its potential as a promising oral insulindelivery platform.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Formulation and Characterization of Sustained-Release Multipolymeric Nanospheres for Oral Insulin with Emphasis on Structural Stability and Release Kinetics

  • 期刊论文

  • 发表日期：

    2026年4月27日

查看全文
  • Aida Kazempourfard,
  • Azney Zuhaily Md. Taib,
  • Khater AL-Japairai,
  • Pornanong Aramwit,
  • Syed Mahmood

摘要

Introduction

Oral delivery of insulin remains a major challenge due to enzymatic degradation, poor intestinal permeability, and low bioavailability. Several studies have reported the development of oral insulin delivery systems as alternatives to parenteral administration, enabling sustained oral delivery compared with injectable insulin.

Methodology

This study aimed to develop and evaluate a sustained-release polymeric nanosphere system for oral insulin delivery using a multi-component formulation strategy. Insulin-loaded nanospheres were prepared using chitosan, sodium alginate, Eudragit E, β-cyclodextrin, and folic acid, and five formulations (F1–F5) were optimised based on particle size, polydispersity index (PDI), zeta potential, and entrapment efficiency.

Results

The optimised formulation showed a mean particle size of 188.9 ± 5.1 nm, a low PDI (0.218), a high positive zeta potential (+ 56.8 ± 2.7 mV), and an entrapment efficiency of 79.84%. In vitro release studies demonstrated pH-dependent sustained release, with minimal insulin release under acidic conditions (pH 1.2) after 2 h, and near-complete release (96%) over 24 h at intestinal pH 6.8. Release kinetics followed first-order and Hixson–Crowell models, indicating diffusion- and erosion-controlled mechanisms. ATR-FTIR and DSC analyses confirmed the absence of chemical incompatibility and suggested molecular dispersion of insulin within the polymeric matrix. Morphological evaluation using optical microscopy, SEM, and ESEM revealed predominantly spherical nanospheres with well-defined structures. Circular dichroism spectroscopy showed preservation of insulin’s α-helical secondary structure after formulation and during refrigerated storage, indicating conformational stability. Physical stability studies demonstrated maintained particle characteristics for up to 45 days at 2–4 °C.

Conclusion

This multi-component nanosphere system effectively protected insulin, enabled sustained release as confirmed by HPLC, and preserved structural integrity, highlighting its potential as a promising oral insulindelivery platform.