Process parameters of microsphere preparation based on propylene carbonate emulsion-precursors

Abstract

Aim

This study aimed for a detailed understanding of the impact of different process parameters involved during celecoxib-loaded microsphere preparation based on propylene carbonate emulsion-precursors.

Methods

Microspheres were prepared by a modified emulsification-solvent extraction method. Performed investigations included polymer solubility and viscosity, microsphere size, morphology and stability, propylene carbonate content as well as celecoxib solid state, content and release.

Results

Rough-walled round microspheres with sizes between 21 µm and 122 µm and an internal sponge-like structure filled with residual propylene carbonate (content between 1.9 ± 0.1% and 6.7 ± 0.5% w/w) were obtained. Encapsulation efficiencies varied between 28.3 ± 0.1% and 66.8 ± 1.0%. The release rates were affected by the polymer concentration, the emulsion phase ratio and the residual propylene carbonate content (t_50% varied between 2.2 hours and 23.4 hours).

Conclusions

This study identified the most relevant process parameters for this new preparation method for the model drug celecoxib.

Keywords:

• Microencapsulation
• process parameters
• propylene carbonate
• PLGA
• celecoxib

Acknowledgement

Daris Grizic would like to acknowledge the German Academic Exchange Service (DAAD) for the financial support (91540177; A/13/91141).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was partially supported by a French Government grant managed by the French National Research Agency under the program “Investissements d’Avenir” with reference ANR-11-LABX-0021.