# Solid Lipid Nanoparticles by Coacervation from Natural Soaps: Preliminary Studies for Oral Delivery of an Insulin Analogue

## TL;DR

Researchers developed solid lipid nanoparticles from natural soaps to improve oral delivery of insulin, showing potential for better gut absorption.

## Contribution

A novel method using coacervation from Shea and Mango soaps to create nanoparticles for oral insulin delivery is proposed.

## Key findings

- Solid lipid nanoparticles enhance peptide permeation into gut sections.
- Spray-drying allows scalable production of re-dispersible oral dosage forms.
- The method shows promise for future in vivo studies on oral insulin efficacy.

## Abstract

Background/Objectives: Oral insulin continues to constitute a challenge due to its low uptake by the gut wall and degradation by gastrointestinal proteolytic enzymes. Such concerns might be surmounted by means of nanoparticle delivery. Methods: In this study, glargine insulin has been loaded into solid lipid nanoparticles prepared via coacervation from Shea and Mango soaps, due to hydrophobic ion pairing. Subsequently, ex vivo tied-up-gut experiments were performed with fluorescently labeled peptide. Additionally, re-dispersible oral solid dosage forms (powders and tablets) were obtained from nanoparticle suspensions via freeze-drying and spray-drying. Results: Solid lipid nanoparticles are capable of enhancing peptide permeation into different gut sections. Furthermore, spray-drying permits the preparation, which can be scaled up, of a re-dispersible powder from the nanoparticle suspension. Conclusions: This engineered process is suitable for the formulation of solid oral dosage forms, such as granulates and tablets, and presents promising potential for oral insulin delivery, paving the way for the assessment of its pharmacological efficacy in further in vivo studies.