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3M Drug Delivery Systems An Evaluation of Analytical Techniques for Characterising the Plume Velocity and the Plume Force of Pulmonary and Nasal Products Chris Blatchford & Gemma Nixon, 3M Drug Delivery Systems, Morley St, Loughborough, UK . Graham Hargrave, Tim Justham & Edward Long, Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, UK . . Introduction The pMDI units were held at an angle so that the plume had a horizontal trajectory. The data from three selected pMDI products also show that measurements can be Text Here – Body copy will vary in size depending on how much text you have to fill the whole poster Two analytical techniques, high speed laser imaging and plume force The actuation was triggered by a solenoid valve with a compressed air supply held at taken at different distances and there is obvious consistency of the data at the 60psi. The trigger was also synchronised to start the video camera. The high different distances (Figure 4). measurements have been investigated for measuring the ex-actuator plume from NOTE* - You cannot reduce your Body Copy smaller than 12 pt type on this template. pulmonary and nasal products. The advantages and disadvantages of the resolution images were transferred to a PC and the digital data manipulated using techniques are discussed with an analysis of data from a range of marketed products. The Leading edge velocity data gives a better indication of the way the plumes from specifically designed in-house software. different pMDI products dissipate with distance (Figure 5). Some devices have Software algorithms were set up to follow the leading edge of the ex-actuator plume plumes with leading edge velocities of more than 20 msec-1 when close to the over the first 10 cm and the distance/time data was converted into distance/velocity actuator but at a distance of 5 cm these have typically reduced to below 15 msec-1. data as shown in Figure 5. Product B has consistently lower plume force and leading edge velocity between 3 and 7 cm firing distance, whereas Product C has the highest force and the highest Spray Force Experimental leading edge velocity. Results The Copley Scientific SFT1000 Spray Force Tester has an integrated Mecmesin AFG 2.5N Force sensor which records the spray force from the evolved plume. During initial testing it was found there was mechanical interference both actuating the unit and pressing the tare button on the force sensor. The instrument was used The spray force data showed that there was a very high range of forces for different Leading Edge Velocity at distance from actuator - High Speed Laser Imaging products and there was a large overlap in the plume forces for pMDI and nasal spray 30.00 products (Figures 2 and 3). 25.00 in a modified configuration with the force sensor and plate re-positioned so they Boxplot of Maximum Spray Force (mN) vs Product 100 Header Here - light blue background Maximum Spray Force (mN) shown in Figure 1. 20.00 Velocity (m/s) were facing in the opposite direction and the actuator held in a separate jig, as 90 80 70 15.00 10.00 60 50 5.00 40 30 0.00 20 0 1 2 3 4 10 0 0 0 ir S le ent te ent te er BDP er aler ade aler i 5 8 L 5 l l l a r m a t a iv il r o odu trov tide cloh Fo oh ics de c or V AR voh voh b i T oh r Ai i v n v i i m o r M A a E E E C Q 0E e so ul m t ec Co n n Fil ide i os O n B l 5 P t Ge ve to im e o t e n d x i r i A e et Ve Fl r S Se Conclusions Product 5 6 7 8 9 10 Distance (cm) Product A Product B Product C Figure 5 – Leading edge velocity by High Speed Laser Imaging for Products A, B and C Figure 2 – Spray Force of pMDI products Conclusions Boxplot of Maximum Spray Force (mN) vs Product Leading edge velocity and spray force measurements are both useful analytical 60 Maximum Spray Force (mN) Figure 1 – Spray Force Tester Modified Set-Up The Spray Force Tester can be set up in two modes, either to measure the maximum force over the duration of the spray plume, or a high speed analogue output. High speed analogue data capture showed that when a force was applied to the plate there was a resonance set up in the sensor at about at about 1kHz. This resonance interfered with the high frequency force of the plume and therefore 50 on a wide range of commercially available inhalation products. The data from three 40 pMDI products show that both plume force and leading edge velocity measurements 30 have detected similar trends i.e. those plumes with a higher leading edge velocity tend to have a higher spray force. 20 Leading edge velocity measurements require sophisticated research equipment and 10 ics r ne e (G all further studies were performed with the instrument in maximum force mode. techniques for the characterisation of spray plumes and this has been demonstrated DP B ) Be se a n co t s 0 a s u 5 u a x eo ol Aq e u n n t i q r o A o s Rh F c a c o N in be h o s R Na se a n o x li R te a in c ri s om n r c ta a n n Sy Ry when the operator presses the buttons or actuates the MDI and from the resonance products (Figure 2) and nasal spray products (Figure 3) at a firing distance of 5cm using 3 shots from 3 devices for each product (n=9). Three pMDI products were Scientific SFT1000 Spray Force Tester is much easier to use and is a less costly option, however there were some imitations including the vibration of the instrument Product The equipment was used to analyse a wide range of commercially available pMDI customised software which is not available as a commercial product. The Copley frequency in the force sensor. Figure 3 – Spray Force of nasal spray products also measured at 3cm, 5cm and 7cm (Figure 4) for comparison with the leading edge velocity experiments. Acknowledgements and References Peak Spray Force - Copley Scientific Spray Force Tester SFT1000. (Error bars indicate data range) The authors would like to thank Mark Copley for helpful discussions and for the loan 200.0 180.0 A method was developed using a pulsed laser (20nsec pulse width) and a synchronised high speed video camera to record images of the ex-actuator pMDI plume at a frequency of 10kHz. The laser beam was configured as a vertical sheet of light which passed through the ex-actuator plume in the opposite direction to the plume trajectory. The plane of light was aligned slightly in front of the nozzle so that any heating affects caused by the high intensity light source would not affect the atomisation process or distort the actuator orifice. The video camera was focused precisely on the laser light plane. 3M Drug Delivery Systems 160.0 Peak Spray Force, mN High Speed Laser Imaging Experimental of a Copley SFT1000 Spray Force Tester 140.0 Gabrio B, Stein S and Velasquez D. 120.0 100.0 A New Method to Evaluate Plume Characteristics of Hydrofluoroalkane and Chlorofluorocarbon Metered Dose Inhalers. 80.0 International journal of Pharmaceutics, Volume 186, Issue 1, 10 September 1999, 60.0 40.0 Pages 3-12. 20.0 0.0 3 cm 5 cm 7 cm Guo C and Doub W. Development of a Novel Technology to Measure impaction Firing Distance Product A Product B Product C Figure 4 – Peak Spray Force using Copley Scientific Spray Force Tester for Products A, B and C Force of Nasal Sprays and Metered Dose Inhalers Using the Texture Analyser. Respiratory Drug Delivery 2006. 3