• Login
    View Item 
    •   UMB Digital Archive
    • School, Graduate
    • Theses and Dissertations All Schools
    • View Item
    •   UMB Digital Archive
    • School, Graduate
    • Theses and Dissertations All Schools
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of UMB Digital ArchiveCommunitiesPublication DateAuthorsTitlesSubjectsThis CollectionPublication DateAuthorsTitlesSubjects

    My Account

    LoginRegister

    Statistics

    Display statistics

    Effervescent Aerosols: A Novel Formulation Technology for Solution and Suspension-type Metered Dose Inhalers

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    Kelkar_umaryland_0373D_10702.pdf
    Size:
    2.750Mb
    Format:
    PDF
    Download
    Author
    Kelkar, Mukul Sunil
    0000-0002-5087-4051
    Advisor
    Dalby, Richard N.
    Date
    2016
    Type
    dissertation
    
    Metadata
    Show full item record
    Abstract
    Pressurized metered dose inhalers are complex drug delivery systems which have revolutionized the treatment of asthma and chronic obstructive pulmonary disease since the 1950s. Since the early 1990s, solution and suspension metered dose inhalers have been formulated using HFA-134a and HFA-227 as the propellants of choice, along with other excipients such as ethanol and oleic acid. Performance of an inhaler is partially dependent upon the size of particles it generates, which is partially dictated by intra-canister pressure. In this dissertation, a novel method of formulation of inhalers- the "effervescent aerosol technology" has been introduced. A propellant consisting of HFA-134a containing dissolved carbon dioxide has been used to formulate solution and suspension inhalers. We hypothesized that dissolution of carbon dioxide in HFA-134a will lead to higher degree of aerosol particle size reduction upon actuation, caused due to the process of effervescence i.e. escape of dissolved carbon dioxide from HFA -134a droplet. Since this is a novel technology, the initial part of the dissertation tested the hypothesis in a custom-designed pressure vessel capable of holding and spraying solution inhaler formulations. Particle size analysis was done using Malvern Spraytec®, a laser diffractometry instrument. Formulations prepared using a mixture of HFA-134a and carbon dioxide showed significantly lower particle sizes compared to analogous, pressure-controlled formulations. In the later part of the dissertation, a method to transfer the formulation from the pressure vessel to commercially viable canisters has been described. Further laser diffractometry experiments showed that solution and suspension inhalers prepared using effervescent aerosol technology consistently produce particles with significantly lower particle sizes than HFA-134a-only inhalers. Cascade impaction testing showed that inhalers prepared using a mixture of HFA-134a and carbon dioxide cause significantly lower throat deposition and show improvements in other crucial performance parameters, when compared to HFA-134a-only formulations. Additionally, spray characterization studies such as spray force and plume geometry have also been conducted. This thesis demonstrates that using a combination propellant of liquefied HFA-134a and dissolved CO2 to prepare solution and suspension-type metered dose inhalers is a viable formulation strategy to achieve improved inhaled drug delivery.
    Description
    University of Maryland, Baltimore. Pharmaceutical Sciences. Ph.D. 2016
    Keyword
    effervescent
    formulation
    Aerosol Propellants
    Metered Dose Inhalers
    Solutions
    Suspensions
    Identifier to cite or link to this item
    http://hdl.handle.net/10713/5487
    Collections
    Theses and Dissertations All Schools
    Theses and Dissertations School of Pharmacy

    entitlement

     
    DSpace software (copyright © 2002 - 2023)  DuraSpace
    Quick Guide | Policies | Contact Us | UMB Health Sciences & Human Services Library
    Open Repository is a service operated by 
    Atmire NV
     

    Export search results

    The export option will allow you to export the current search results of the entered query to a file. Different formats are available for download. To export the items, click on the button corresponding with the preferred download format.

    By default, clicking on the export buttons will result in a download of the allowed maximum amount of items.

    To select a subset of the search results, click "Selective Export" button and make a selection of the items you want to export. The amount of items that can be exported at once is similarly restricted as the full export.

    After making a selection, click one of the export format buttons. The amount of items that will be exported is indicated in the bubble next to export format.