The interplay between trehalose and dextran as spray drying precursors for cationic liposomes

Area of Science:

• Pharmaceutical Technology
• Drug Delivery Systems
• Biomaterials Science

Background:

• Oral delivery of liposomes faces challenges due to harsh gastrointestinal conditions.
• Solid-state formulations and gastro-resistant devices are crucial for successful liposome delivery.
• Spray drying is a key technique for creating stable, solid-state liposome formulations.

Purpose of the Study:

• To evaluate trehalose-dextran mixtures as dehydration precursors for spray-dried liposomes.
• To determine the protective capacity of these excipients during the drying process.
• To optimize liposome concentration and rehydration kinetics in the final dry formulation.

Main Methods:

• Spray drying of CAF®04 liposomes using various trehalose-dextran mixtures.
• Analysis of liposome protection and content in the resulting dry powder.
• Assessment of rehydration kinetics for the optimized formulations.
• Quantification of lipid concentration in the spray-dried liposomes.

Main Results:

• A mixture of 8.5% dextran and 76.5% trehalose effectively protected CAF®04 liposomes during spray drying.
• Liposome content was maintained at 15% of the dry powder formulation.
• Rehydration kinetics showed slight improvement with up to 8.5% dextran.
• A 2.4-fold increase in lipid concentration (from 3 mM to 7.245 mM) was achieved.

Conclusions:

• Trehalose is a significant carrier for spray drying CAF®04 liposomes.
• Incorporating small amounts of dextran can modulate the rehydration properties of spray-dried liposomes.
• This approach enhances liposome stability and lipid concentration for improved oral delivery potential.