Nanosizing of sodium ibuprofen by SAS method

Abstract

The micro/nanosizing of drug particles has been identified as a potentially effective and broadly applicable approach. Sodium ibuprofen is a chiral nonsteroidal anti-inflammatory drug. This work aimed to recrystallize particles of sodium ibuprofen, reducing its particle size, using a Supercritical Anti-solvent (SAS) technique performed in a modified supercritical fluid extraction unit. For this purpose, the phase equilibrium of the system sodium ibuprofen+acetone+CO2 was also investigated at temperatures ranging from 35 to 55°C. Phase equilibrium data exhibited solid–vapor–liquid and vapor–liquid transitions. The average particle sizes of the SAS-precipitated ibuprofen were below 380±84nm for all the SAS conditions tested, reducing the original dimension of the samples from micrometric to nanometric order. The best SAS operational conditions, in order to produce the lowest estimated particle size and higher crystallinity were, respectively, using 0.5 and 1.0mgibuprofen/mL, and 1mLsolution/min, 1kgCO2/h, 110bar and 35°C. The DSC results indicated that, besides reducing the ibuprofen particle size, the SAS process appears to have changed the original sodium ibuprofen to the acid form. The PXRD and RAMAN results indicated that the SAS process at 1mgibuprofen/mL, 1mLsolution/min, 1kgCO2/h, 110bar and 35°C is the best condition to obtain ibuprofen particles with higher crystallinity.