Controlling in situ crystallization of pharmaceutical particles within the spray dryer

Meng Wai Woo, May Ginn Lee, Soroush Shakiba, Shahnaz Mansouri

Research output: Contribution to journalReview ArticleResearchpeer-review

10 Citations (Scopus)


Introduction: Simultaneous solidification and in situ crystallization (or partial crystallization) of droplets within the drying chamber are commonly encountered in the spray drying of pharmaceuticals. The crystallinity developed will determine the functionality of the powder and its stability during storage. This review discusses strategies that can be used to control the in situ crystallization process. Areas covered: The premise of the strategies discussed focuses on the manipulation of the droplet drying rate relative to the timescale of crystallization. This can be undertaken by the control of the spray drying operation, by the use of volatile materials and by the inclusion of additives. Several predictive approaches for in situ crystallization control and new spray dryer configuration strategies are further discussed. Expert opinion: Most reports, hitherto, have focused on the crystallinity of the spray dried material or the development of crystallinity during storage. More mechanistic understanding of the in situ crystallization process during spray drying is required to guide product formulation trials. The key challenge will be in adapting the mechanistic approach to the myriad possible formulations in the pharmaceutical industry.

Original languageEnglish
Pages (from-to)1315-1324
Number of pages10
JournalExpert Opinion on Drug Delivery
Issue number11
Publication statusPublished - 2 Nov 2017


  • amino acids
  • crystallization
  • drying history
  • excipients
  • lactose
  • mannitol
  • pharmaceuticals
  • protein stability
  • Spray drying

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