Continuous release of rh-interferon alpha-2a from triglyceride matrices.

Area of Science:

• Biomaterials Science
• Drug Delivery Systems
• Protein Therapeutics

Background:

• Biodegradable polymeric matrices for controlled release have limitations.
• Triglycerides offer a potential alternative for sustained drug delivery.

Purpose of the Study:

• To develop a triglyceride-based delivery system for sustained continuous protein release.
• To evaluate the effect of polyethylene glycol (PEG) and hydroxypropyl-beta-cyclodextrin (HP-beta-CD) on protein release and stability.

Main Methods:

• Preparation of tristearin implants containing lyophilized rh-interferon alpha-2a (IFN-alpha) and varying concentrations of PEG.
• Incorporation of HP-beta-CD into the matrices.
• In vitro release studies.
• Scanning electron microscopy (SEM) and mercurial porosimetry for matrix characterization.

Main Results:

• Tristearin implants containing 10% PEG enabled continuous release of over 90% of IFN-alpha over 1 month.
• HP-beta-CD enhanced protein release by stabilizing IFN-alpha and improving solubility.
• SEM and porosimetry indicated the formation of an interconnected pore network within the matrices.
• Released protein was primarily in monomeric form.

Conclusions:

• Triglyceride-based matrices, particularly with PEG and HP-beta-CD, represent a promising alternative to polymeric systems for sustained protein delivery.
• The developed system offers controlled and continuous release of therapeutic proteins like IFN-alpha.
• The matrix structure facilitates protein diffusion and release, maintaining protein integrity.