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Physicochemical characteristics of chlorofluorohydrocarbon-based inhalation aerosols

Thesis/Dissertation:

Abstract

The aim of this work was to gain a better understanding of the physicochemical factors which affect the formulation of suspension inhalation aerosols. The adsorption of six nonionic and cationic surfactants onto Spherisorb has been investigated. The results were analyzed by calculating the area occupied by one adsorbed molecule at the surface and by comparing these values for each surfactant. The amount of each surfactant adsorbed was correlated with the number of sites on that surfactant molecule which could interact with the surface. The stability of suspensions, produced by both the model colloid Spherisorb, and by the drug isoprenaline sulfate, after adsorption of the surfactants, has been assessed by measuring settling times and rising times. The most stable suspension were found to be those which had the greatest amounts of long chain fatty acid surfactant adsorbed on their surface. A comparison was made between the effective stabilizing properties of Span 85 and oleic acid on various drug suspension. It was found that Span 85 gave the most stable suspension. Inhalation aerosol suspensions of isoprenaline sulfate were manufactured using the same surfactants used in the adsorption and suspension stability studies and were analyzed by measuring the particle size distributions of the  More>>
Authors:
Publication Date:
Jan 01, 1985
Product Type:
Thesis/Dissertation
Reference Number:
EDB-89-093951
Resource Relation:
Other Information: Thesis (Ph. D.). BRD-80,387
Subject:
54 ENVIRONMENTAL SCIENCES; AEROSOLS; CHEMICAL PROPERTIES; PHYSICAL PROPERTIES; DRUGS; SYNTHESIS; ADSORPTION; COLLOIDS; MANUFACTURING; MOLECULAR STRUCTURE; ORGANIC CHLORINE COMPOUNDS; ORGANIC FLUORINE COMPOUNDS; STABILITY; SURFACE AREA; SURFACTANTS; SUSPENSIONS; DISPERSIONS; ORGANIC COMPOUNDS; ORGANIC HALOGEN COMPOUNDS; SOLS; SORPTION; SURFACE PROPERTIES; 500100* - Environment, Atmospheric- Basic Studies- (-1989)
OSTI ID:
6158758
Research Organizations:
Aston Univ., Birmingham (UK)
Country of Origin:
United Kingdom
Language:
English
Availability:
UMI, Dissertation Information Service, 300 North Zeeb Road, Ann Arbor, MI 48106.
Submitting Site:
JMT
Size:
Pages: 402
Announcement Date:

Thesis/Dissertation:

Citation Formats

Ashurst, I C. Physicochemical characteristics of chlorofluorohydrocarbon-based inhalation aerosols. United Kingdom: N. p., 1985. Web.
Ashurst, I C. Physicochemical characteristics of chlorofluorohydrocarbon-based inhalation aerosols. United Kingdom.
Ashurst, I C. 1985. "Physicochemical characteristics of chlorofluorohydrocarbon-based inhalation aerosols." United Kingdom.
@misc{etde_6158758,
title = {Physicochemical characteristics of chlorofluorohydrocarbon-based inhalation aerosols}
author = {Ashurst, I C}
abstractNote = {The aim of this work was to gain a better understanding of the physicochemical factors which affect the formulation of suspension inhalation aerosols. The adsorption of six nonionic and cationic surfactants onto Spherisorb has been investigated. The results were analyzed by calculating the area occupied by one adsorbed molecule at the surface and by comparing these values for each surfactant. The amount of each surfactant adsorbed was correlated with the number of sites on that surfactant molecule which could interact with the surface. The stability of suspensions, produced by both the model colloid Spherisorb, and by the drug isoprenaline sulfate, after adsorption of the surfactants, has been assessed by measuring settling times and rising times. The most stable suspension were found to be those which had the greatest amounts of long chain fatty acid surfactant adsorbed on their surface. A comparison was made between the effective stabilizing properties of Span 85 and oleic acid on various drug suspension. It was found that Span 85 gave the most stable suspension. Inhalation aerosol suspensions of isoprenaline sulfate were manufactured using the same surfactants used in the adsorption and suspension stability studies and were analyzed by measuring the particle size distributions of the suspension and the emitted doses. The results were found to correlate with the adsorption and suspension stability studies and it was concluded that a deflocculated suspension was preferable to a flocculated suspension in inhalation aerosols provided that the drug density was less than the propellant density. The application of this work to preformulation studies was also discussed.}
place = {United Kingdom}
year = {1985}
month = {Jan}
}