Evaluation of process parameters involved in chitosan microsphere preparation by the o/w/o multiple emulsion method

Area of Science:

• Biopolymer science
• Materials science
• Pharmaceutical technology

Background:

• Chitosans are versatile biopolymers with significant potential in medical and pharmaceutical applications.
• Developing effective drug delivery systems for hydrophobic drugs remains a challenge in pharmaceutical science.

Purpose of the Study:

• To prepare hydrophobic drug-loaded microspheres using an oil-in-water-in-oil (o/w/o) multiple emulsion technique.
• To investigate the impact of critical process variables on microsphere characteristics and drug encapsulation efficiency.

Main Methods:

• Utilized an o/w/o multiple emulsion technique for microsphere preparation.
• Employed two chitosans with varying molecular weights and deacetylation degrees.
• Investigated the effects of acetic acid concentration and drug-polymer ratio using ketoprofen as a model hydrophobic drug.

Main Results:

• The multiple emulsion method successfully produced well-formed chitosan microspheres with good yields.
• Acetic acid concentration in chitosan solutions significantly affected microsphere particle size and drug content.
• The lowest theoretical drug-to-chitosan ratio resulted in the highest drug encapsulation efficiencies.

Conclusions:

• The o/w/o multiple emulsion technique is a viable method for producing hydrophobic drug-loaded chitosan microspheres.
• Process parameters, specifically acetic acid concentration and drug-polymer ratio, are critical for controlling microsphere properties.
• Optimizing the drug-polymer ratio is essential for maximizing drug encapsulation efficiency in these chitosan-based delivery systems.