Surgery – Liquid medicament atomizer or sprayer – Pre-pressurized container holding medicament
Reexamination Certificate
1998-06-18
2001-07-17
Weiss, John G. (Department: 3761)
Surgery
Liquid medicament atomizer or sprayer
Pre-pressurized container holding medicament
C128S200140, C128S200240, C128S203120, C128S203250
Reexamination Certificate
active
06260549
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a device for dispensing medication in the respiratory tract, and more particularly to a breath-activated device with provision for open and closed-mouth techniques, electronic measurement and control, and electro-mechanical activation.
2. Background
Asthma is a disease that is a growing epidemic in this country and affects 14.6 million Americans, including 5 million children. (Cowley G., & Underwood A., Why Ebonie Can't Breathe, Newsweek, May 26, 1997, 129(21), 58-64). According to the American Lung Association, the number of sufferers has risen by 61 percent since the early 1980's. Id. The death toll from asthma has also nearly doubled, to a tragic 5000 per year. Id. These statistics are appalling considering that today, physicians have many more types of medications available for treatment.
The majority of medications for asthma treatment are intended for delivery to the lung. In this way, the drug can most quickly reverse the acute breathing problem that asthma causes to the sufferer. Delivery of medication directly to the lung also allows use of less drug, minimizing systemic side effects, since only the lung is affected by the disease.
Techniques of medication delivery to the lungs for asthma sufferers have a long history and have seen many improvements. However, significant disadvantages remain in the delivery systems in use today. The nineteenth century saw the invention and use of the glass bulb nebulizer. (Hampson N. B., Mueller M. P., Reduction In-Patient Timing Errors Using A Breath-Activated Metered Dose Inhaler, Chest, August 1994, 106(2), 462-465). At the turn of the century, cigarettes laced with atropine were used. Id. The first pressure metered dose inhaler (MDI) was introduced in 1956. (Newman S. P., Weisz A. W., Talaee N., Clarke S. W., Improvement Of Drug Delivery With A Breath-Activated Pressurized Aerosol For Patients With Poor Inhaler Technique, Thorax, 1991, 4(46), 712-716). Though bulky, noisy and cumbersome to use, the first breath activated aerosol inhaler was introduced a number of years ago. Id. In an effort to improve medication delivery, spacer devices used with MDI's were introduced in the 1970's. (Iula, A. K., Flynn C. L., Delucca F., Comparative Study Of The In Vitro Dose Delivery And Particle Size, Distribution, Characteristics Of An Azmacort Metered-Dose Inhaler In Combination With Four Different Spacer Devices, Current Therapeutic Research, August 1997, 58(8), 544-554).
Nebulizers have been the treatment mainstays for acute asthmatics in emergency departments. Nebulizers offer an advantage of delivering a higher dose of medication to the lung than MDI's (Newman S. P., Sted K. P., Resader S. J., Hooper G., Zierenberg B., Efficient Delivery To The Lungs Of Flunisolide Aerosol From A New Portable Hand-Held Multi-Dose Nebulizer, Journal of Pharm. Science, September 1996, 85(9), 960-964) and once set up, the nebulizer requires no training and minimal cooperation from the patient. With a nebulizer, there is also less deposition of medication in the oropharynx as compared to MDI's. (Battistini A., The Best Way To Apply Aerosol Therapy, Pediatric Med. Chir, March-April 1995, 17(2), 97-103). The deficiencies of nebulizers are that they are expensive, time consuming, bulky, non-portable, and usually AC current-dependent. A nebulizer also takes minutes to deliver its dose, and needs considerable time to set-up for that delivery. The output of nebulizers is device-dependent and there is significant inter-nebulizer and intra-nebulizer output variance. (National Institutes of Health: National Heart, Lung, and Blood Institute. Guidelines For The Diagnosis And Management Of Asthma, July 1997, Bethesda Md., NIH Publication No. 97-44051, 1-154).
Another treatment technique uses dry powder medication as a substitute for aerosol medication. Children and elderly patients often find dry powder inhalers easier to use than MDI's. (Newman S. P., Weisz A. W., Talaee N., Clarke S. W., Improvement Of Drug Delivery With A Breath-Activated Pressurized Aerosol For Patients With Poor Inhaler Technique, Thorax, 1991, 4(46), 712-716). It is reported that inhaler induced symptoms are lower with some dry powder inhalers (dry powder budesonide and turbutan) as compared to MDI's. (Pauwels R. A., Hargreave F. E., Camus P., Bukoski M., Stahl E., A 1-Year Study Of Turbohaler Vs Pressurized Metered Dose Inhaler In Asthmatic Patients, Chest, July 1996, 110(1), 53-57). Certain dry powder inhalers are also reported to deliver more drug to the lungs than an equivalent aerosol inhaler. (Borgstrom L., Derom E., Stahl E., Wahlin-Boll E., Pauwels R., The Inhalation Device Influences Lung Deposition And Bronchodilating Effect Of Terbutaline, American Journal of Respiratory and Critical Care Medicine, May 1996, 153(5), 1636-1640). However, another study reported that dry powder inhalers deliver only 10% of the inhaled medication dose to the lungs. (Taburet A. M., Schmidt B., Pharmacokinetic Optimisation Of Asthma Treatment, Pharmacokinetics, May 1994, 26(5), 396-418/published erratum in August 1994, 27(2), 149)
Currently, there are also breath activated dry powder inhalers on the market. Dry powder breath activated inhalers do not rely on coordination between activation and inhalation and therefore are easier for the patient to use. However, existing dry powder inhalers, including breath activated devices, have a number of disadvantages. The medication dose is lost if a patient exhales through the device. (National Institutes of Health: National Heart, Lung, and Blood Institute. Guidelines For The Diagnosis And Management Of Asthma, July 1997, Bethesda Md., NIH Publication No. 97-44051, 1-154). It is also necessary to inhale rapidly to use a dry powder inhaler properly. Id. Rapid inhalation may not be possible during an acute asthma exacerbation. (Boulet L.P., d'Amours P., Berube D., Rouleau M., Parent J. G., Pelletier C. & Touchette C., Update On Inhalation Therapy In Asthma And Obstructive Bronchopulmonary Diseases, Union Med. Canada, January 1994, 123(1), 23-31§). Thus, inspiratory flow may not be sufficient when medication is most needed.
Devices that do not rely on patient inhalation technique have an advantage in medication delivery for asthmatics. Spacers are one such device that is being promoted as a way to deliver aerosol from MDI's to the patient's lung without the need for skillful patient technique. Spacers used with MDI's also offer an advantage to MDI's alone in that less medication is deposited in the oropharynx, reducing local side effects. (National Institutes of Health: National Heart, Lung, and Blood Institute. Guidelines For The Diagnosis And Management Of Asthma, July 1997, Bethesda Md., NIH Publication No. 97-44051, 1-154). Larger volume spacers (>600 cc) increase lung delivery in MDI's in patients with poor MDI technique. Id. This is due to the large droplets precipitating out in the spacer holding chambers prior to inspiration.
However, spacers also present certain disadvantages. Currently many spacers are being sold as universal for all aerosol canisters. A study found significant differences in the amount of drug available for inhalation when different spacers were used as inhalation aids with different drugs. (Barry P. W., O'Callaghan C., Do Multiple Actuations Of Salbutamol MDI Into A Spacer Device Reduce The Amount Of Drug Recovered In Respirable Range? European Respiratory Journal, September 1994, 7(9), 1707-1709). Spacers can also vary widely as to the amount of respirable dose delivered. (Iula, A. K., Flynn C. L., Delucca F., Comparative Study Of The In Vitro Dose Delivery And Particle Size, Distribution, Characteristics Of An Azmacort Metered-Dose Inhaler In Combination With Four Different Spacer Devices, Current Therapeutic Research, August 1997, 58(8), 544-554)
Another major problem with spacers is that multiple actuations into the volumetric spacer does not linearly increase the amount of drug
Clavius Devices Inc.
Morgan & Finnegan , LLP
Weiss John G.
Weiss, Jr. Joseph F.
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