Ethyl formate - alternative dispersed solvent useful in preparing PLGA microspheres

Area of Science:

• Materials Science
• Chemical Engineering
• Pharmaceutical Technology

Background:

• Methylene chloride, a common solvent in microsphere fabrication, poses toxicity concerns.
• Developing safer, effective alternatives is crucial for sustainable pharmaceutical manufacturing.
• Ethyl formate presents a promising, less toxic solvent option.

Purpose of the Study:

• To develop and evaluate novel ethyl formate-based emulsion processes for poly-D,L-lactide-co-glycolide (PLGA) microsphere fabrication.
• To compare the performance of ethyl formate with methylene chloride in terms of solvent evaporation and process efficiency.
• To investigate the impact of ethyl formate quenching parameters on microsphere characteristics.

Main Methods:

• Emulsification of a polymeric dispersed phase in a polyvinyl alcohol aqueous solution using ethyl formate.
• Microsphere hardening via solvent evaporation and quenching techniques.
• Evaluation of encapsulation efficiency using progesterone as a model drug.

Main Results:

• Successful fabrication of PLGA microspheres using ethyl formate-based processes.
• Achieved high average encapsulation efficiency of progesterone (95.2+/-2.7%).
• Ethyl formate exhibited a 2.1 times faster evaporation rate than methylene chloride, shortening hardening time.
• Optimized quenching timing was found to significantly influence microsphere size distribution and aggregation.

Conclusions:

• Ethyl formate-based emulsion processes are effective for producing PLGA microspheres.
• These processes offer a safer and potentially more efficient alternative to traditional methylene chloride methods.
• Further optimization of quenching parameters can control microsphere properties for specific drug delivery applications.