肺部给药-英文课件.ppt
《肺部给药-英文课件.ppt》由会员分享,可在线阅读,更多相关《肺部给药-英文课件.ppt(70页珍藏版)》请在三一文库上搜索。
1、PULMONARY DRUG DELIVERY,Tarun K. Mandal, Ph.D.,Pulmonary Drug Delivery,MISCELLANEOUS PREPARATIONS,Pulmonary Drug Delivery,AEROSOLS Aerosols are defined as colloidal systems of very finely subdivided liquid or solid particles dispersed in and surrounded by a gas.,Pulmonary Drug Delivery,Classificatio
2、ns of Aerosol Products: 1. space sprays 2. surface coating 3. aerated sprays,Pulmonary Drug Delivery,1. Space sprays. Disperse the active ingredients as a finely divided spray with the particle no longer than 50 m in diameter. 2. Surface coating. Disperse larger particle, generally produce a wet or
3、course spray.,Pulmonary Drug Delivery,3. Aerated sprays. Disperse medicated foams, vaginal foams, shaving cream.,Pulmonary Drug Delivery,Advantages of the Aerosol Dosage form: Minimum Contamination Maximum Stability Reduces the irritation; cooling effect Easy to control: physical form; particle size
4、; dose Clean process; require no wash-up,Pulmonary Drug Delivery,The aerosols are used in pharmacy for local or systemic delivery of drugs. The total sales of beta agonist and cromolyn sodium aerosols in the United States 1984 1988 Beta agonist $121,000,000 $238,000,000 Cromolyn sodium $12,000,000 $
5、56,000,000.,Pulmonary Drug Delivery,Aerosols for local (topical) treatment: 1. Topical medication may be applied in a uniform thin layer to the skin, without touching the affected area 2. Aerosols are also used in the diagnosis, prevention or control of lung disease,Pulmonary Drug Delivery,Aerosols
6、for systemic treatment: Polypeptide drugs The advantages of therapeutic aerosols 1. The drugs begin to act very rapidly 2. Smaller dose can be used than with oral or intravenous delivery 3. Reduction in the incidence of systemic side effect.,Pulmonary Drug Delivery,OVERALL STRUCTURE AND FUNCTION OF
7、THE RESPIRATORY TRACT FUNCTION: The primary function of the respiratory tract is gas exchange A secondary function is cleaning and humidifying of the incoming air to prevent damage of this vital organ Only delivery by breathing via mouth is considered for aerosol dosage forms.,Pulmonary Drug Deliver
8、y,STRUCTURE: Upper airways oropharynx and larynx Lower airways trachea which is followed by successive bifurcations into bronchi and bronchioli. terminal bronchioli then divide into respiratory bronchioli until the ultimate respiratory zone, the alveoli is reached.,Pulmonary Drug Delivery,BLOOD AND
9、LYMPH FLOW IN THE RESPIRATORY TRACT Pulmonary vasculature forms a separate circuit from the systemic circulation. The main pulmonary artery starts in the right ventricle, then it divides into two branches for the left and right lungs. Drugs absorbed into the pulmonary circulation will avoid the firs
10、t-pass hepatic effect, although they could be metabolized in the respiratory tract.,Pulmonary Drug Delivery,PHYSICAL MECHANISMS OF PARTICLE DEPOSITION IN RESPIRATORY TRACT The three mechanisms of aerosol kinetics govern the majority of particle deposition within the respiratory tract.,Pulmonary Drug
11、 Delivery,1. INERTIAL IMPACTION: Particles of diameters ranging from a few microns to greater than 100. The inertia of an airborne particle will tend to cause it to travel in its initial path when the supporting airstream is suddenly deflected (turbinates, bifurcations).,Pulmonary Drug Delivery,2. S
12、EDIMENTATION: Every particle allowed to fall in air will accelerate to a terminal settling velocity (v) where the force of gravity is balanced by the resistance of the air through which the particle is falling:,Pulmonary Drug Delivery,2 r2 (d1 - d2) g v =- 9 n r =radius of the particle; d1 =density
13、of the particle; d2 =density of air; n =viscosity of air; g = gravitational constant.,Pulmonary Drug Delivery,Factors that may increase particle deposition by sedimentation are: a) increase in particle size b) decrease in airflow (breath- holding or long slow breathing).,Pulmonary Drug Delivery,3. D
14、IFFUSION: Particle deposition by diffusion or brownian motion predominates for very small particles (5 or less) and occurs predominantly in the periphery of the lung (respiratory bronchiole and alveolus).,Pulmonary Drug Delivery,FACTORS AFFECTING DEPOSITION A wide range of other factors influences t
15、he deposition of aerosols within the respiratory tract.,Pulmonary Drug Delivery,1. MODE OF INHALATION: The most important features of inhalation are a) inhaled volume b) flow rate c) breath holding pause maintained at end inspiration,Pulmonary Drug Delivery,2. AEROSOL PROPERTIES: The vital physical
16、property of the aerosol itself is the aerodynamic diameter (the product of physical diameter and the square root of density).,Pulmonary Drug Delivery,aerodynamic diameter 2 m -deposition in the oropharynx -less reaches the most peripheral parts of the lung The ideal size for a therapeutic aerosol sh
17、ould not be more than 5 m to penetrate into the tracheobronchial tree and smaller airways if peripheral deposition is required.,Pulmonary Drug Delivery,AEROSOL FORMULATION The Aerosol Principle 1. Product Concentrate 2. Propellant,Pulmonary Drug Delivery,Product Concentrate 1. Active Ingredients 2.
18、Antioxidants 3. Surface Active Agent 4. Solvent,Pulmonary Drug Delivery,Propellant Liquified GasMixture Example: Fluorinated Hydrocarbon Nonliquified Gas Example: Carbon Dioxide, Nitrogen, Nitrous Oxide Advantages of Nitrogen as Propellent: 1. It is insoluble in the product concentrate 2. It is an o
19、dorless and tasteless gas,Pulmonary Drug Delivery,The pressure of an Aerosol is critical to its performance. It can be controlled by: 1. The type and amount of propellant 2. Nature/Amount of the product concentrate,Pulmonary Drug Delivery,Space Sprays- 85% Propellant Surface Sprays- 30-70% Propellan
20、t Aerated Sprays- 6-10% Propellant Blends of the various liquified gas propellants are generally used.,Pulmonary Drug Delivery,AEROSOLS AND RAOULTS LAW The vapor pressure of pure propellant 11 (MW 137.4) at 210 C is p110 = 13.4 pounds/square inch (psi) and that of propellant 12 (MW 120.9) is p120 =
21、84.9 psi.,Pulmonary Drug Delivery,A 50:50 mixture of gram weight of the two propellants consists of 50 gm 137.4 g mole-1 =0.364 mole of propellant 11, and 50 gm 120.9 g mole-1 = 0.414 mole of propellant 12. What is the partial pressure of propellants 11 and 12 in the mixture and what is the total va
22、por pressure of this mixture?,Pulmonary Drug Delivery,p11= n11/(n11+n12) p110 =0.364/(0.364+0.414)(13.4)=6.27 psi p12=n12/(n11+n12) p120 =0.414/(0.364+0.414)(84.9)=45.2psi The total vapor pressure of the mixture is 6.27 + 45.2 = 51.5 psi,Pulmonary Drug Delivery,TOXICITY The Physiologic Effect Must B
23、e Considered. Fluorinated Hydrocarbons have a relatively low order of toxicity. Rapid and repeated use may exhibit Cardiotoxic Effect. Cardiac toxicity is likely to be a problem only for the occasional adult or child who deliberately abuses his/her metered dose inhaler, apparently to satisfy a cravi
24、ng for fluorinated hydrocarbon.,Pulmonary Drug Delivery,AEROSOL SYSTEMS Two-Phase Systems Liquid Phase 1. Liquified Propellant 2. Product Concentrate Vapor Phase,Pulmonary Drug Delivery,Three-Phase Systems 1. Water immiscible liquid propellant 2. Highly aqueous product concentrate 3. Vapor phase.,Pu
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- 肺部 英文 课件
链接地址:https://www.31doc.com/p-3567390.html