Shruti Bhat PhD, MBA, Lean Six Sigma Black Belt
  • Home
  • About Shruti
  • Consulting
  • Workshops
  • Patents
  • Articles
    • Case Studies
    • Innovation Portfolio Development & Patents
    • Drugs-in-the- making
    • Culture Change & Business Transformation
    • Operational Excellence, Quality & Continuous Improvement
  • Books
  • Digital
  • Blog
  • Videos
  • Contact

Pulmonary route for mucosal drug delivery- I

7/4/2017

0 Comments

 
Choosing the lungs to deliver drugs beyond airways is not new. Nicotine and other anesthetics have been delivered to the blood stream this way for many years. However, the high surface area for absorption, the low level of enzymatic activity, the high physiologic pH together with rapid onset of drug action are key reasons why lung is a good site of delivery for peptides and proteins. It is particularly good for those, which have short half-lives.
Pulmonary route for mucosal drug delivery_1

The key to delivering peptides & proteins to lungs is to target the small airways where the endothelial cells are directly connected with the alveolar endothelium. To deliver drugs deep into the lungs require particles of a precise size and a device, which delivers the drug regardless of a patient’s breathing patterns. Delivering drugs by inhalation requires precision engineering for optimum results. 

Inhalation devices- an engineering overview  

Today’s inhalation devices have many design criteria, which they must meet. Not only is it important that they deliver the drug in the correct form, to the correct target site they must also offer the patient ease of use, guarantee repeatable performance and low cost and all of which should be coupled to aesthetic appeal and social acceptability. 

The large number of devices currently available can be amalgamated into 3 groups broadly, nebulisers, metered dose inhalers (MDIs) and dry powder inhalers (DPIs). For each, the basic operating principles, advantages and drawbacks will be reviewed followed by a consideration of possible enhancements and the future for devices in general. 

Nebulisers-  

Nebulisers could mostly be described as devices for generating aerosols using an external energy source to achieve atomization. Commercially, there are two basic systems available grouped by the energy source used, air jet nebulisers wherein a stream of high velocity air (dry and clean) is passed over a source of liquid (water) containing the drug. The resulting negative pressure causes the liquid to be drawn into the air stream from the reservoir. The air flow rate, the rate of which liquid is drawn into the stream and to a certain extent the surface tension of the liquid determine the initial droplet size. The stream may then be impacted into a baffle system of plates and filters, which refines the aerosol by removing the large droplets and releasing an aerosol, which is closer to being mono-dispersed at the target size. Typically for air jet nebulisers, this is in the range of 2-4 mm. 

Ultrasonic nebulisers are the high frequency vibrations of piezo electric crystals to impart kinetic energy to the liquid; some of this energy in turn is used to create new surface area in the liquid, which will assume the most stable form of spherical droplets, due to its surface tension. These new droplets of liquid retain some of the imparted kinetic energy, which throws them clear of the bulk liquid, forming an aerosol in the nebuliser.           

Both types of nebulisers can produce similar size distributions of aerosol, the ultrasonic systems having the advantage that they can nebulise relatively large volumes of liquid, without the associated high airflow requirement and resultant evaporative losses. 

Metered dose inhalers (MDI)-  

Metered dose inhalers (MDIs) can be viewed as a number of individual interactive components- the valve, the propellant & the inhaler (activator). The propellant systems normally used consist of a cocktail of one or more chloro-fluorocarbon (CFC). These compounds possess properties, which make them difficult to replace easily, such as volatility, low toxicity and low flammability. Because these propellants possess a distinct equilibrium vapor pressure at a given temperature in a closed MDI system that pressure is acting throughout the system and is effectively constant through the life of the pack, as long as liquid propellant remains (excluding preferential evaporation). 

The portability, close consistency, accurate targeting, low cost and discrete use of MDIs mean that in terms of total numbers, they are the most frequently prescribed form of inhalation device. Unfortunately there are 2 main disadvantages. The first of these has developed in recent years, in as much as MDI are no longer considered environmentally acceptable (an issue which is beyond the scope of this article) due to the use of chloroflurocarbon propellants. The second disadvantage is a more long-standing problem and is one of misuse, patient in co-ordination and cold cough syndrome. Breath actuated inhalers (BAIs) and inhalers with spacer chamber offer solution to the problems. 

​Continued in Part 2 ...

Follow Shruti on Twitter, Facebook, YouTube, LinkedIn
0 Comments

Your comment will be posted after it is approved.


Leave a Reply.

    Shruti Bhat, global leader in business turnaround, operational excellence and continuous improvement

    New Book Released!

    top ten strategic decision-making tools for operational excellence

    Shruti's YouTube Channel ...

    Picture

    Blog Categories

    All
    3D Printing
    5S
    Agile
    Artificial Intelligence
    Automation
    Balanced Score Card
    Biotechnology
    Books
    Business Turnaround
    Case Studies
    Change Management
    Chemical Industry
    CMMI
    Continuous Improvement
    Design Thinking
    Digitalization
    Drug Delivery
    External News Links
    Food Industry
    Hall Of Fame
    Healthcare
    Hoshin Kanri
    HR Development
    Innovation
    ISO
    Just In Time
    Kaizen
    Leadership
    LEAN
    Lean Six Sigma
    Life Sciences
    Machine Learning
    Manufacturing
    Medical Devices
    Mistake Proofing
    Motivational Cards
    Nanotechnology
    Operations
    Packaging
    Patents
    Personal Products
    Process Improvement
    Product Development
    Productivity Increase
    QbD
    Quality Management
    Robotics
    Scrum
    Service Industry
    Six Sigma
    Strategy
    Supply Chain Logistics
    Telecom Industry
    TQM
    Videos
    Voice Of Customer
    Workshops

    Shruti's books...

    Picture
    shruti bhat, business process management, continuous improvement
    kaizen for pharmaceutcials, medical devices and biotech industry book by Dr Shruti Bhat
    Book on Continuous improvement tools by Dr Shruti Bhat
    kaizen for leaders, continuous process improvement tool to increase profit and organizational excellence by shruti bhat
    kaizen, shruti bhat, continuous improvement, quality, operations management
    Picture
    how to overcome challenges of creating effective teams
    how to lead a successful business transformation

    ​Micro-Learning
    ​Partner

    Picture

    Publishing Partner

    fast read books, business management books, health and wellness books, spiritual guidance books, best online book store

    Wellness
    ​Partner

    Picture
© Copyright 1992- 2022 Dr. Shruti Bhat ALL RIGHTS RESERVED.
See Terms and Conditions for details on this site usage.
SHRUTI BHAT, CONTACT
Click to connect.
Created by Macro2Micro Media