Solid lipid micro-particles carrying insulin formed by solvent-in-water emulsion-diffusion technique

Area of Science:

• Pharmaceutical Sciences
• Materials Science

Background:

• Oral insulin delivery remains a significant challenge due to insulin's degradation in the gastrointestinal tract.
• Developing effective delivery systems is crucial for improving patient compliance and therapeutic outcomes.

Purpose of the Study:

• To produce solid lipid insulin-loaded micro-particles using a solvent-in-water emulsion-diffusion technique.
• To evaluate the potential of these micro-particles as oral delivery systems for insulin.

Main Methods:

• Utilized isobutyric acid as the solvent phase, glyceryl monostearate or cetyl palmitate as the lipid matrix, and soya lecithin/taurodeoxycholate as emulsifiers.
• Employed a high-shear homogenizer at 50°C to achieve sub-micron particle size and increase lipid load.
• Assessed insulin encapsulation efficiency, chemical stability, and in vitro release profiles.

Main Results:

• Achieved approximately 80% insulin encapsulation efficiency with no observed chemical modification of insulin.
• Demonstrated very low in vitro insulin release, with an initial burst effect of 20%.
• Observed a 24% loss of encapsulated insulin after pepsin treatment, indicating partial degradation.

Conclusions:

• Solid lipid micro-particles show promise as a viable system for oral insulin delivery.
• The developed micro-particles offer a potential solution to overcome insulin's oral bioavailability challenges.
• Further research is warranted to optimize the system for enhanced stability and controlled release in vivo.