title: Stability and aerosolization of pressurized metered dose inhalers containing thymopentin nanoparticles produced using a bottom-up process.
abstract: The objective of this study was to investigate the stability and aerosolization of pressurized metered dose inhalers (pMDIs) containing thymopentin nanoparticles. Thymopentin nanoparticles, fabricated by a bottom-up process, were suspended in hydrofluoroalkane (HFA) 134a together with cineole and/or n-heptane to produce pMDI formulations. The stability study of the pMDIs obtained was carried out at ambient temperature for 6 months. The amount of thymopentin and the aerosolization properties of pMDIs were determined using high-performance liquid chromatography (HPLC) and a twin-stage impinger (TSI), respectively. Based on the results, thymopentin nanoparticles were readily suspended in HFA 134a with the aid of cineole and/or n-heptane to form physically stable pMDI formulations, and more than 98% of the labeled amount of thymopentin and over 50% of the fine particle fraction (FPF) of the pMDIs were achieved. During storage, it was found that for all pMDIs more than 97% of the labeled amount of thymopentin and FPF greater than 47% were achieved. Moreover, the size of thymopentin nanoparticles in propellant containing cineole and n-heptane showed little change. It is, therefore, concluded that the pMDIs comprising thymopentin nanoparticles developed in this study were stable and suitable for inhalation therapy for systemic action.
authors.affiliation: School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, PR China.
authors.forename: Yinhe
authors.initials: Y
authors.lastname: Tan
authors.forename: Zhiwen
authors.initials: Z
authors.lastname: Yang
authors.forename: Xin
authors.initials: X
authors.lastname: Pan
authors.forename: Meiwan
authors.initials: M
authors.lastname: Chen
authors.forename: Min
authors.initials: M
authors.lastname: Feng
authors.forename: Lili
authors.initials: L
authors.lastname: Wang
authors.forename: Hu
authors.initials: H
authors.lastname: Liu
authors.forename: Ziyun
authors.initials: Z
authors.lastname: Shan
authors.forename: Chuanbin
authors.initials: C
authors.lastname: Wu
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage*; D000336:Aerosols; D002626:Chemistry, Pharmaceutical; D005617:Chlorofluorocarbons, Methane; D002851:Chromatography, High Pressure Liquid; D003511:Cyclohexanols / Q000737:chemistry; D004355:Drug Stability; D004356:Drug Storage; D000077591:Eucalyptol; D006536:Heptanes / Q000737:chemistry; D006845:Hydrocarbons, Fluorinated; D054709:Lecithins; D036501:Metered Dose Inhalers; D046529:Microscopy, Electron, Transmission; D039821:Monoterpenes / Q000737:chemistry; D053758:Nanoparticles; D010316:Particle Size; D016305:Thymopentin / Q000008:administration & dosage*; D005466:Fluorocarbons
chemical_list: D000276:Adjuvants, Immunologic; D000336:Aerosols; D005617:Chlorofluorocarbons, Methane; D003511:Cyclohexanols; D000077591:Eucalyptol; D006536:Heptanes; D006845:Hydrocarbons, Fluorinated; D054709:Lecithins; D039821:Monoterpenes; D016305:Thymopentin; C028618:n-heptane; C094049:apaflurane; D005466:Fluorocarbons