Spray freeze drying of small nucleic acids as inhaled powder for pulmonary delivery

作     者：Wanling Liang Alan Y.L.Chan Michael Y.T.Chow Fiona F.K.Lo Yingshan Qiu Philip C.L.Kwok Jenny K.W.Lam 

作者机构：Department of Pharmacology and Pharmacy Li Ka Shing Faculty of Medicine The University of Hong Kong Advanced Drug Delivery Group Faculty of Pharmacy The University of Sydney 

出 版 物：《Asian Journal of Pharmaceutical Sciences》 (亚洲药物制剂科学（英文）)

年 卷 期：2018年第13卷第2期

页      面：163-172页

核心收录：

学科分类：100702[医学-药剂学] 1007[医学-药学(可授医学、理学学位)] 1006[医学-中西医结合] 100602[医学-中西医结合临床] 10[医学] 

基　　金：funded by the Health and Medical Research Fund, Hong Kong (15140962) Research Grant Council, Hong Kong (17110414) 

主　　题：Inhalation Pulmonary delivery Small interfering RNA Spray freeze drying 

摘      要：The therapeutic potential of small nucleic acids such as small interfering RNA(siRNA) to treat lung diseases has been successfully demonstrated in many in vivo studies. A major barrier to their clinical application is the lack of a safe and efficient inhaled *** this study, spray freeze drying was employed to prepare dry powder of small nucleic *** and herring sperm DNA were used as bulking agent and model of small nucleic acid therapeutics, respectively. Formulations containing different solute concentration and DNA concentration were produced. The scanning electron microscope(SEM) images showed that the porosity of the particles increased as the solute concentration decreased. Powders prepared with solute concentration of 5% w/v were found to maintain a balance between porosity and robustness. Increasing concentration of DNA improved the aerosol performance of the formulation. The dry powder formulation containing 2% w/w DNA had a median diameter of 12.5 μm, and the aerosol performance study using next generation impactor(NGI) showed an emitted fraction(EF) and fine particle fraction(FPF) of 91% and 28% respectively. This formulation(5% w/v solute concentration and 2% w/w nucleic acid) was adopted subsequently to produce siRNA powder. The gel retardation and liquid chromatography assays showed that the siRNA remained intact after spray freeze drying even in the absence of delivery vector. The siRNA powder formulation exhibited a high EF of 92.4%and a modest FPF of around 20%. Further exploration of this technology to optimise inhaled siRNA powder formulation is warranted.