Pharmaceutical Research

, Volume 16, Issue 2, pp 249–254

Protein Inhalation Powders: Spray Drying vs Spray Freeze Drying

  • Yuh-Fun Maa
  • Phuong-Anh Nguyen
  • Theresa Sweeney
  • Steven J. Shire
  • Chung C. Hsu
Article

DOI: 10.1023/A:1018828425184

Cite this article as:
Maa, YF., Nguyen, PA., Sweeney, T. et al. Pharm Res (1999) 16: 249. doi:10.1023/A:1018828425184

Abstract

Purpose. To develop a new technique, spray freeze drying, for preparing protein aerosol powders. Also, to compare the spray freeze-dried powders with spray-dried powders in terms of physical properties and aerosol performance.

Methods. Protein powders were characterized using particle size analysis, thermogravimetric analysis, scanning electron microscopy, X-ray powder diffractometry, and specific surface area measurement. Aerosol performance of the powders was evaluated after blending with lactose carriers using a multi-stage liquid impinger or an Anderson cascade impactor. Two recombinant therapeutic proteins currently used for treating respiratory tract-related diseases, deoxyribonuclase (rhDNase) and anti-IgE monoclonal antibody (anti-IgE MAb), were employed and formulated with different carbohydrate excipients.

Results. Through the same atomization but the different drying process, spray drying (SD) produced small (∼3 μm), dense particles, but SFD resulted in large (∼8−10 μm), porous particles. The fine particle fraction (FPF) of the spray freeze-dried powder was significantly better than that of the spray-dried powder, attributed to better aerodynamic properties. Powders collected from different stages of the cascade impactor were characterized, which confirmed the concept of aerodynamic particle size. Protein formulation played a major role in affecting the powder's aerosol performance, especially for the carbohydrate excipient of a high crystallization tendency.

Conclusions. Spray freeze drying, as opposed to spray drying, produced protein particles with light and porous characteristics, which offered powders with superior aerosol performance due to favorable aerodynamic properties.

spray freeze drying spray drying dispersibility fine particle fraction liquid impingement cascade impaction aerodynamic particle size 

Copyright information

© Plenum Publishing Corporation 1999

Authors and Affiliations

  • Yuh-Fun Maa
    • 1
  • Phuong-Anh Nguyen
    • 1
  • Theresa Sweeney
    • 1
  • Steven J. Shire
    • 1
  • Chung C. Hsu
    • 1
  1. 1.Pharmaceutical Research and DevelopmentGenentech, Inc.South San Francisco

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