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UK scientists have used a laser beam trap to examine how drug particles from asthma inhalers behave as they are projected through the air. Their findings could improve the effectiveness of inhalers for the over 5 million people in the UK suffering from asthma.

Over 73 million inhalers are used every year in the UK. By studying how the expelled drug particles might behave as they enter the human respiratory tract and travel into the lungs, this new research could lead to an improvement in the formulation of these drug delivery systems, increasing their effectiveness whilst reducing negative side effects.

Using the Octopus laser imaging facility at the Science and Technology Facilities Council (STFC) Central Laser Facility, the scientists trapped individual solid particles of the drug salbutamol sulphate. They suspended them in air to test how they behave in conditions modelled to simulate those in the human respiratory system.

This is the first time that tests on these microscopic particles have been carried out in an environment that mimics their journey from inhaler to lung. Their research is published today (13 November 2014) in the Royal Society of Chemistry journal, Chemical Communications.

“The human respiratory tract is anatomically evolved to prevent particles being inhaled”, said Dr Peter Seville from the University of Birmingham’s School of Clinical and Experimental Medicine, one of the researchers on the project.Dr Andy Ward from the STFC Central Laser Facility explained, “We captured each particle by trapping it between two focused laser beams, and then tested its behaviour in different temperatures and levels of humidity. Our tests show how water is adsorbed by following changes in chemical bond vibrations. Usually such tests are done on a glass slide so this is the first time the particles have been tested while airborne, as they would be when travelling through the respiratory tract”

“To overcome the natural defence mechanisms of the body, complex delivery devices and extremely small drug particles are required. These particles are typically 2-5 micron in diameter, making them approximately a tenth of the width of a human hair. Any moisture that clings to the particles as they travel from inhaler to lung is likely to increase the particles’ size, and this may affect the site of particle deposition within the lung. It can result in the drug being deposited in a non-ideal site, giving rise to less effective treatment and potentially an increase in side effects.”

Using Raman spectroscopy techniques to measure the vibration and wavelength of light from molecules, the research team was able to provide a new method of studying the salbutamol sulphate as it exited from a commercially-available inhaler.

Lead investigator, Dr Francis Pope from the University of Birmingham, said,” This research could lead to more efficient inhalers to deliver drugs for respiratory problems. Our results will also inform pharmaceutical companies who may be looking to improve the chemical structure of the drug, increasing effectiveness whilst reducing negative side effects. We would not have been able to do this work without the unique capability of these lasers to capture and levitate particles, providing a new way to test the performance of the inhalers.”They discharged the inhaler into the optical laser trap, without changing the drug’s physical and chemical properties, captured a microscopic particle in air and recorded its size, shape and chemical signature to show evidence of any water adsorption. This all happened within a matter of seconds, closely replicating the time, relative humidity and trajectory of the particle in the lung.

These pressurised inhalers, which deliver a measured dose of drugs with each use, account for around 70% of inhaler sales in the UK, and are the most frequently used devices for asthma and chronic obstructive pulmonary disease.

The research team comprised scientists from the Universities of Birmingham and Cambridge, Imperial College London and the STFC Central Laser Facility, based at the Research Complex at Harwell, Oxfordshire.

The research was funded by STFC, NERC and the European Research Council.

More information: 

Marion O'Sullivan 
STFC Press Office
Tel: 01793 445627
Mob: 07824 888990

Notes for Editors:

1. Rapid interrogation of the physical and chemical characteristics of salbutamol sulphate aerosol from a pressurised metered-dose inhaler (pMDI) by H-J Tong, C Fitzgerald, P J Gallimore, M Kalberer, M K Kuimova, P C Seville, A D Ward and F D Pope is published in the RSC journal Chemical Communications.
    
2. Raman spectroscopy research from STFC’s Central Laser Facility is currently opening doors to make life better for people by being applied to a number of other applications, such as non-invasive testing for breast cancer or testing for dangerous substances being carried in liquids at airports.
    
3. STFC Central Laser Facility (CLF) at the Research Complex at Harwell is a partnership between its staff and the large number of members of UK and European universities who use the specialised laser equipment provided to carry out a broad range of experiments in physics, chemistry and biology. The CLF’s wide ranging applications include experiments in physics, chemistry and biology, accelerating subatomic particles to high energies, probing chemical reactions on the shortest timescales and studying biochemical and biophysical process critical to life itself.

4. The University of Birmingham is a truly global university producing world-leading research and is ranked amongst the world’s top 100 institutions. Birmingham benefits from mutual partnerships with a wide range of international institutions and hosts a large international community of researchers and students.

   With almost 5,000 international students from more than 150 countries, and 31% of academic staff from overseas, Birmingham’s campus is truly a diverse and global place which attracts the brightest and best international students and staff.

   The University of Birmingham was named The Times and The Sunday Times University of the Year 2013/14.

5. Imperial College London: Consistently rated amongst the world's best universities, Imperial College London is a science-based institution with a reputation for excellence in teaching and research that attracts 14,000 students and 6,000 staff of the highest international quality. Innovative research at the College explores the interface between science, medicine, engineering and business, delivering practical solutions that improve quality of life and the environment - underpinned by a dynamic enterprise culture.

   Since its foundation in 1907, Imperial's contributions to society have included the discovery of penicillin, the development of holography and the foundations of fibre optics. This commitment to the application of research for the benefit of all continues today, with current focuses including interdisciplinary collaborations to improve global health, tackle climate change, develop sustainable sources of energy and address security challenges.

   In 2007, Imperial College London and Imperial College Healthcare NHS Trust formed the UK's first Academic Health Science Centre. This unique partnership aims to improve the quality of life of patients and populations by taking new discoveries and translating them into new therapies as quickly as possible.

6. University of Cambridge : The mission of the University of Cambridge is to contribute to society through the pursuit of education, learning and research at the highest international levels of excellence. To date, 90 affiliates of the University have won the Nobel Prize.

   Founded in 1209, the University comprises 31 autonomous Colleges, which admit undergraduates and provide small-group tuition, and 150 departments, faculties and institutions.

   Cambridge is a global university. Its 19,000 student body includes 3,700 international students from 120 countries. Cambridge researchers collaborate with colleagues worldwide, and the University has established larger-scale partnerships in Asia, Africa and America.

   The University sits at the heart of one of the world’s largest technology clusters. The ‘Cambridge Phenomenon’ has created 1,500 hi-tech companies, 14 of them valued at over US$1 billion and two at over US$10 billion. Cambridge promotes the interface between academia and business, and has a global reputation for innovation.

7. The Science and Technology Facilities Council (STFC) is keeping the UK at the forefront of international science and tackling some of the most significant challenges facing society such as meeting our future energy needs, monitoring and understanding climate change, and global security. The Council has a broad science portfolio and works with the academic and industrial communities to share its expertise in materials science, space and ground-based astronomy technologies, laser science, microelectronics, wafer scale manufacturing, particle and nuclear physics, alternative energy production, radio communications and radar.

   STFC operates or hosts world class experimental facilities including in the UK the ISIS pulsed neutron source, the Central Laser Facility, and LOFAR, and is also the majority shareholder in Diamond Light Source Ltd. It enables UK researchers to access leading international science facilities by funding membership of international bodies including European Laboratory for Particle Physics (CERN), the Institut Laue Langevin (ILL), European Synchrotron Radiation Facility (ESRF) and the European Southern Observatory (ESO).

   STFC is one of seven publicly-funded research councils. It is an independent, non-departmental public body of the Department for Business, Innovation and Skills (BIS). Follow us on Twitter at @STFC_Matters.

8. NERC is the UK's main agency for funding and managing research, training and knowledge exchange in the environmental sciences. Our work covers the full range of atmospheric, Earth, biological, terrestrial and aquatic science, from the deep oceans to the upper atmosphere and from the poles to the equator. We co-ordinate some of the world's most exciting research projects, tackling major issues such as climate change, environmental influences on human health, the genetic make-up of life on Earth, and much more. NERC is a non-departmental public body. We receive around £370m of annual funding from the Department for Business, Innovation & Skills (BIS).

9. Set up in 2007 by the EU, the European Research Council(ERC) is the first pan-European funding organisation for frontier research. It aims to stimulate scientific excellence in Europe by encouraging competition for funding between the very best, creative researchers of any nationality and age. The ERC also strives to attract top researchers from anywhere in the world to come to Europe.

   Under the new EU research and innovation programme Horizon 2020, the ERC has a substantially increased budget of over €13 billion.