analytical chemistry tests
Ethylene
Oxide Content based on Simulated Use
This test is generally performed on devices that are not implanted
or in use for extended periods, and analysis of the total EO
content of the device may not be required. The test simulates
clinical use of the device including temperature and time of
exposure to tissue to determine the potential residual EO dose
to a patient.
Ethylene
Oxide Content Following Exhaustive Solvent Extraction
The test article is extracted repeatedly with the appropriate
solvent (acetone or water are commonly used) and the EO content
of the extracts is measured until either no more EO is found
or until less than 10% of the EO found in the initial extract
is detected. The sum of the EO detected in all of the extracts
is reported.
Ethylene
Oxide Content by Exhaustive Headspace Analysis
The test article is repeatedly heated in a sealed container
and the EO content of the gaseous headspace is measured. Number
of heatings, their duration and temperature are determined in
accordance with AAMI guidelines. The sum of the EO detected
in each of the heatings is reported.
Ethylene
Glycol and Ethylene Chlorohydrin in Aqueous Extracts
Ethylene oxide can react with water to form ethylene glycol,
and if chloride is present, ethylene chlorohydrin may also form.
The reactions are pH, temperature and material dependent. Water
extraction (either simulated use or exhaustive extraction) followed
with gas chromatographic analysis is employed for determination
of these two residual products.
Particle
Sizing and Counting
Ethox STS offers particle counting services for both pharmaceutical
products and medical devices following USP, JP, EP or other
guidelines. To protect samples against any inadvertent particulate
contamination, test articles are carefully prepared in a class
100 laminar flow hood within hardwall environmentally controlled
rooms. Particle enumeration is then accomplished utilizing either
light obscuration (electronic particle counter) or light microscopy
following USP <788>.
The
preferred method of particle enumeration is by electronic
particle counter. However, some samples due to viscosity or
due to the presence of surfactants, may be unsuitable for that
method and must counted visually by collecting any particulate
contamination onto a filter. In the latter case experienced
personnel count and size particles visually using a binocular
microscope equipped with the appropriate reticules and lighting.
Ethylene
Oxide residuals analyzed according to ISO 10993-7
• Ethylene Oxide (aqueous extraction)
• Ethylene Oxide (solvent extraction)
• Ethylene Oxide (headspace)
• Ethylene Chlorohydrin (aqueous extraction)
• Ethylene Glycol (aqueous extraction)
Particle
Analysis
• Analysis of injectable products using USP <788>)
by electronic counter (Light Obscuration) or by microscopic
inspection of membrane filter-collected samples
• Ethox STS also performs particle analysis of pharmaceutical
products conforming to the requirements of the JP and EP.
• Analysis of particle contamination of non-pharmaceutical
products following ANSI/AAMI AT6 and ISO 8536-4.
Gas
Chromatography
• Trace solvent analysis
• Contact lens residual monomers (HEMA, EGDM, MEHQ)
• Ethylene oxide gas mixture analysis
• Ethylene oxide sterilization chamber content analysis
• Development of gas chromatographic methods
• Residual glutaraldehyde analysis
High
Performance Liquid Chromatography (HPLC)
• Quantitative and stability-indicating assays of pharmaceutical
products using isocratic and gradient separations.
• Development and validation of HPLC methods using USP-defined
principles
USP
General Chapters Assays
• Identification Tests USP <191>: Identification of
a variety of anions and cations using non-instrumental methods.
• Arsenic Method I USP <211>: This test is used to
determine the presence of trace amounts of arsenic in inorganic
materials.
• Heavy Metals USP <231>: Total heavy metal (lead,
mercury, bismuth, arsenic, antimony, tin, cadmium, sliver, copper
and molybdenum) content is determined through visual comparison
with known lead standards.
- Method I This method is used unless otherwise specified
in the USP monograph.
- Method II This method is used when specified by USP
for substances that interfere with heavy metal analysis by Method
I.
• Residue on ignition USP <281>
• Volatile Organic Impurity Assays USP <467>: This method is generally used to look at solvent residuals that remain after drug production or purification processes.
• Physicochemical Tests, Plastics, USP <661>: Extracts
from plastics are evaluated using the complete battery of tests
described in USP including nonvolatile residue, residue on ignition,
heavy metals and buffering capacity
• Loss on drying USP <731>
• Loss on ignition USP <733>
• Melting Range or Temperature USP <741>
• pH USP <791>
• Specific Gravity USP <841>
Refractive
Index
Using an Abbe refractometer Spectrophotometric
Scanning
• UV/Visible
• Infrared (FTIR)
Medical
Device Cleaning Studies
The Ethox STS Chemistry Department works with our Reusable Device
group to design and perform cleaning studies. Cleaning efficacy
may be determined by use of a total protein assay, or by other
client-specified measures of contamination removal.
To learn more call Joy Perry at 1.800.836.4850 or e-mail us!
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