University Of Bath Researchers Use Freeman Powder Tester In New Dry Powder Inhaler Studies

Researchers at the University of Bath (UK) are using the FT4 Powder Rheometer from Freeman Technology to understand and optimise the performance of dry powder inhalers (DPIs). Recently published data highlight a direct correlation between the flow properties of excipient powders, measured with the FT4 under aerating conditions, and the effectiveness of drug delivery of carrier based DPI formulations. The research will also be presented at RDD Respiratory Drug Delivery 2008 (11-15 May, Arizona, USA) by Drs Jagdeep Shur and Robert Price of the Pharmaceutical Surface Science Group, Department of Pharmacy and Pharmacology, University of Bath.

Relatively coarse excipient particles are used to improve the flow properties of the micronized active pharmaceutical ingredients (APIs) used in DPIs. As a patient inhales, drawing air through the device, the resulting blend is fluidised, stripping API from the excipient, for deposition in the lung. This process is promoted by the inclusion of excipient fines.

With the FT4, a universal powder tester, samples can be characterised under aerating/fluidising conditions. In this research the instrument was used to measure aerated flow energy, bulk density, compressibility and permeability for various DPI blends. A direct correlation was observed between aerated flow energy and fine particle dose – the amount of formulation deposited in the lung - which both increased with increasing fines.

The results suggest that higher fines concentrations increase the resistance of the bed to flow, ultimately subjecting the powder to higher aerodynamic drag forces during fluidisation. These forces encourage the removal of API from the excipient, enhancing drug delivery to the lung.

About Freeman Technology
Freeman Technology is a specialist company pioneering the measurement and understanding of powders and their flow properties. Founded in 1989, the company developed the novel, patented technology that forms the core of its Powder Rheometer system at its design and manufacturing centre in Worcestershire, UK where all manufacturing takes place in an ISO 9001:2000 accredited environment. The FT4 Powder Rheometer is a universal powder tester that provides three complementary approaches in a single instrument: measurement of bulk properties including permeability, bulk density and compressability; shear property determination with automated shear cells; and dynamic flowability using patented methodology. In April 2007 the company received the Queen's Award for Enterprise in Innovation.

Freeman systems are installed around the world in a diverse range of industries. Applications range from optimising new formulations and improving the efficiency of manufacturing processes to the establishment of QC criteria for raw materials, intermediates and final product. www.freemantech.co.uk

About the Pharmaceutical Surface Science Research Group
The pharmaceutical surface science research group was established by Dr Robert Price at the Department of Pharmacy and Pharmacology, University of Bath. A major research interest of the group has been in the area of particle interactions and their influence on the bulk properties of powder systems. Their research has focussed on the use of surface sensitive techniques to measure the environmental and physical factors that govern bulk properties of particulate systems. Specific areas of research include measuring particulate interactions in dry powder inhalation formulations and suspension based pressurised metered dose inhaler formulations and the development, processing and optimisation of active pharmaceutical ingredients and excipients for inhalation formulations. The development of a systematic and scientific approach to formulation science has provided both an invaluable insight into the physico-chemical properties which govern formulations and practical solutions for pharmaceutical applications, which is highly significant to the advancement and knowledge base of the pharmaceutical sciences. www.bath.ac.uk/pharmacy/staff/price.shtml

SOURCE: Freeman Technology Ltd