Pharmaceutical Research

, Volume 27, Issue 9, pp 1977–1986 | Cite as

Inhalable Microparticles as Carriers for Pulmonary Delivery of Thymopentin-Loaded Solid Lipid Nanoparticles

  • Yan-Zhen Li
  • Xun Sun
  • Tao GongEmail author
  • Jie Liu
  • Jiao Zuo
  • Zhi-Rong ZhangEmail author
Research Paper



Microparticles containing solid lipid nanoparticles (SLNs) are receiving increased attention as carriers for the lung delivery of the SLNs. Thus, we aim to prepare the hybrid microparticles and thoroughly evaluate their feasibility for the pulmonary drug delivery.


The microparticles were prepared by co-spray-drying the thymopentin (TP5)-loaded SLNs with bulking agents. Thereafter, we systematically estimated the potential of the microparticles as the carriers for the pulmonary delivery of the SLNs, including the investigations of their characteristics, aerodynamic properties, pharmacokinetics and pharmacodynamics.


The spherical and hollow microparticles presented a size of 4.1 ± 0.1 μm and a low tap density of 0.175 ± 0.02 g/cm3. In addition, the microparticles showed a high aerosolization efficiency (emitted dose of 98.0% ± 1.23% and respirable fraction of 51.07% ± 1.21%). Furthermore, the SLNs could be easily recovered from the microparticles without essential changes on their characteristics and the drug release behavior. The pharmacokinetic and pharmacodynamic studies suggested that, compared to i.v. TP5 solution, the bioavailability and therapeutic efficacy of TP5 were remarkably strengthened after the pulmonary administration of the microparticles.


Taken together, we believe the microparticles were suitable for inhalation and possesed an ample potential for the pulmonary delivery of the SLNs.


pulmonary delivery microparticles solid lipid nanoparticles spray-drying thymopentin 



area under the curve


confocal laser scanning microscope


emitted dose


encapsulation efficacy


dry powder inhaler


fluorescein isothiocyanate


high performance liquid chromatography


intravenous injection


monoclonal Antibodies


mean residence time


phosphate buffer


polydispersity index


respirable dose


respirable fraction


standard deviation


scanning electron microscopy


solid lipid nanoparticles


superoxide dismutase




twin stage impinger


water in oil


water in oil in water



This work was funded by the National S & T Major Project of China (Grant No: 2009ZX09310–002) and the National Science Foundation of PR China (No.30873165).


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Copyright information

© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  1. 1.Key Laboratory of Drug Targeting and Novel Drug Delivery Systems West China School of PharmacySichuan UniversityChengduPeople’s Republic of China

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