University of Surrey

Test tubes in the lab Research in the ATI Dance Research

Effects of relative humidity on flowability and dispersion performance of lactose mixtures

Lu, X-Y, Chen, L, Wu, Chuan-Yu, Chan, H-K and Freeman, T (2017) Effects of relative humidity on flowability and dispersion performance of lactose mixtures Materials, 10 (6), 592.

materials-10-00592-v2.pdf - Version of Record

Download (3MB) | Preview
[img] Text
materials-192523 - revised.docx - Accepted version Manuscript
Restricted to Repository staff only

Download (1MB)


The flowability and dispersion behavior are two important physicochemical properties of pharmaceutical formulations for dry powder inhalers (DPIs). They are usually affected by the environmental conditions, such as temperature and relative humidity (RH). However, very few studies have been focused on the relationship between the two properties and their dependence on RH during storage. In this research, model pharmaceutical formulations were prepared using mixtures of coarse and fine lactose. The fractions of fines in the mixtures were 0%, 5%, 10% and 20%, respectively. These blends were stored at four different RH, 0%, 30%, 58% and 85%, for 48 hours. The FT4 Powder Rheometer was used to evaluate the powder flowability, and the Malvern Spraytec® laser diffraction system was employed to assess the powder dispersion performance. The results indicated that both the flow and dispersion properties of lactose blends deteriorate after being stored at 85% RH, but improved after being conditioned at 58% RH. The fine particle fractions (FPFs) of the blends with 5% and 10% fine fractions and the as-received coarse lactose decreased when they were conditioned at 30% RH. For the blend with 20 % fine fraction, a high RH during storage (i.e., 85%RH) affected the dispersion property, but had a limited influence on its flowability. While, for the coarse lactose powder, the different RH conditions only affected its flowability, but not the dispersion results. A strong correlation between the powder flowability and its dispersion performance was found.

Item Type: Article
Divisions : Faculty of Engineering and Physical Sciences > Chemical and Process Engineering
Authors :
Lu, X-Y
Chen, L
Chan, H-K
Freeman, T
Date : 29 May 2017
DOI : 10.3390/ma10060592
Copyright Disclaimer : Copyright 2017 The Author(s). This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).
Uncontrolled Keywords : relative humidity; lactose; dry powder inhalation; flowability; dispersion
Depositing User : Melanie Hughes
Date Deposited : 26 May 2017 07:44
Last Modified : 16 Jan 2019 18:52

Actions (login required)

View Item View Item


Downloads per month over past year

Information about this web site

© The University of Surrey, Guildford, Surrey, GU2 7XH, United Kingdom.
+44 (0)1483 300800