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Study of Lysozyme-Loaded Poly-L-Lactide (PLLA) Porous Microparticles in a Compressed CO2 Antisolvent Process
College of Chemical Engineering, Huaqiao University, Xiamen 361021, China
Institute of Pharmaceutical Engineering, Institute of Biomaterials and Tissue Engineering, Huaqiao University, Xiamen 361021, China
These authors contribute equally to this work.
* Author to whom correspondence should be addressed.
Received: 5 May 2013; in revised form: 7 July 2013 / Accepted: 14 August 2013 / Published: 19 August 2013
Abstract: Lysozyme (LSZ)-loaded poly-L-lactide (PLLA) porous microparticles (PMs) were successfully prepared by a compressed CO2 antisolvent process in combination with a water-in-oil emulsion process using LSZ as a drug model and ammonium bicarbonate as a porogen. The effects of different drug loads (5.0%, 7.5% and 10.0%) on the surface morphology, particle size, porosity, tapped density and drug release profile of the harvested PMs were investigated. The results show that an increase in the amount of LSZ added led to an increase in drug load (DL) but a decrease in encapsulation efficiency. The resulting LSZ-loaded PLLA PMs (LSZ-PLLA PMs) exhibited a porous and uneven morphology, with a density less than 0.1 g·cm−3, a geometric mean diameter of 16.9–18.8 μm, an aerodynamic diameter less than 2.8 μm, a fine particle fraction (FPF) of 59.2%–66.8%, and a porosity of 78.2%–86.3%. According to the results of differential scanning calorimetry, the addition of LSZ improved the thermal stability of PLLA. The Fourier transform infrared spectroscopy analysis and circular dichroism spectroscopy measurement reveal that no significant changes occurred in the molecular structures of LSZ during the fabrication process, which was further confirmed by the evaluation of enzyme activity of LSZ. It is demonstrated that the emulsion-combined precipitation with compressed antisolvent (PCA) process could be a promising technology to develop biomacromolecular drug-loaded inhalable carrier for pulmonary drug delivery.
Keywords: PLLA; porous microparticles; PCA process; emulsion; pulmonary drug delivery
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MDPI and ACS Style
Kang, Y.-Q.; Zhao, C.; Chen, A.-Z.; Wang, S.-B.; Liu, Y.-G.; Wu, W.-G.; Su, X.-Q. Study of Lysozyme-Loaded Poly-L-Lactide (PLLA) Porous Microparticles in a Compressed CO2 Antisolvent Process. Materials 2013, 6, 3571-3583.
Kang Y-Q, Zhao C, Chen A-Z, Wang S-B, Liu Y-G, Wu W-G, Su X-Q. Study of Lysozyme-Loaded Poly-L-Lactide (PLLA) Porous Microparticles in a Compressed CO2 Antisolvent Process. Materials. 2013; 6(8):3571-3583.
Kang, Yong-Qiang; Zhao, Chen; Chen, Ai-Zheng; Wang, Shi-Bin; Liu, Yuan-Gang; Wu, Wen-Guo; Su, Xiao-Qian. 2013. "Study of Lysozyme-Loaded Poly-L-Lactide (PLLA) Porous Microparticles in a Compressed CO2 Antisolvent Process." Materials 6, no. 8: 3571-3583.