Department of Chemical and Food Engineering, University of Salerno, Via Ponte Don Melillo, 84084 Fisciano-Salerno, Italy.
J Pharm Sci. 2010 Mar;99(3):1484-99. doi: 10.1002/jps.21920.
Supercritical fluid emulsion extraction is an innovative technology that uses supercritical carbon dioxide (SC-CO(2)) to extract the dispersed oily phase of an emulsion. This technology was used to produce poly-lactic-co-glycolic acid (PLGA) microspheres charged with two common NSAIDs: piroxicam (PX) and diclophenac sodium (DF). Single (O/W) and double (W/O/W) emulsions were tested and a comparative study between the characteristics of the microspheres obtained by SC-CO(2) extraction and the ones produced by conventional solvent evaporation (SE) is proposed. Varying the droplet dimensions, microspheres with mean diameters (MDs) of 1, 2, and 3 microm were obtained; however, the microspheres produced by SC-CO(2) gave always a better reproduction of the MD of original droplets because aggregation phenomena often modify the mean size and distribution of the microparticles produced by SE. Moreover, very efficient drug loadings (88% w/w of DF in PLGA using W/O/W emulsion and 97% of PX w/w in PLGA starting from O/W emulsion) were measured in the products obtained by SC-CO(2), respectively; whereas, the SE produced a drug loading of 30% in the case of double emulsion and of 70% for single emulsion. Solvent residue of 10 ppm was also measured by SC-CO(2) technology against the 600 ppm of the SE products. The release profiles of the entrapped drugs were also monitored to check the structure of the microspheres produced by this new technology.
超临界流体乳液萃取是一种创新技术，它使用超临界二氧化碳（SC-CO2）来萃取乳液的分散油相。该技术用于制备载有两种常见非甾体抗炎药（NSAIDs）的聚乳酸-共-羟基乙酸（PLGA）微球：吡罗昔康（PX）和双氯芬酸钠（DF）。测试了单（O/W）和双（W/O/W）乳液，并提出了通过 SC-CO2 萃取获得的微球与通过常规溶剂蒸发（SE）生产的微球的特性的比较研究。通过改变液滴尺寸，获得了平均直径（MD）为 1、2 和 3 微米的微球；然而，SC-CO2 生产的微球总是能更好地再现原始液滴的 MD，因为聚集现象经常改变 SE 生产的微粒子的平均尺寸和分布。此外，通过 SC-CO2 分别在 W/O/W 乳液中测得载有 88% w/w 的 DF 和在 O/W 乳液中起始时载有 97% w/w 的 PX 的非常高的药物负载量（PLGA 中的 DF）；而 SE 生产的双乳液的药物负载量为 30%，单乳液的药物负载量为 70%。通过 SC-CO2 技术还测量了 10 ppm 的溶剂残留，而 SE 产品的残留溶剂为 600 ppm。还监测了包封药物的释放曲线，以检查这种新技术生产的微球的结构。
