Volume 10, Issue 2
Agilent Practical
Solutions
Newsletter
Critical Path for PVT Success
In This Issue:
The Disintegration Apparatus
2
TruAlign Dissolution Vessel 3
Dissolution Workstation Software 4
Agilent 8453 Online UV
Multicomponent Dissolution
5
Dissolution and Vibration
6
The USP Performance Verification Test (PVT) criteria were
significantly altered with the new lot of prednisone tablets,
P1I300, released on March 1, 2010. This lot of tablets, which is a
continuation of lot P0E203 (1), has different acceptance criteria
based on a separate collaborative study to address accuracy and
precision, as well as minor modifications to the recommended
testing criteria. The new criteria call for both a whole-assembly
geometric mean to be within a range and a %CV to be met in
order to pass on a given apparatus. Also, the new testing criteria
offer options for both single- and dual-stage testing.
The purpose of the new specifications is to account for variability
of the dissolution apparatus, which a range alone is not able to
do. Variability can come from a number of sources including the
dissolution apparatus, the accessories, the analyst, and laboratory
environment. It can be difficult to determine which of these plays a
role in a failing run, and after a failure, all of these variables should
be evaluated for potential impact on the dissolution test.
Continued on p. 2
Critical Path: continued
Agilent validation chemists perform the
PVT test on all brands of dissolution
apparatus. As a result, we see a broad
spectrum of results and, where necessary,
perform failure investigations in order
to understand the root cause. Our
application engineers coach individuals
requiring assistance with the PVT and
have found that the areas most correlated
to dissolution failure with lot P1I300 are:
vessel geometry, centering, improper
deaeration, improper sampling and
filtration, stirring vessels prior to starting
the dissolution test, rough or inaccurate
pouring of media, maintenance issues, and
paddle/basket condition.
Vessels
Vessels have been the single largest
cause of failures with the PVT. Vesselrelated failures are correlated to the use of
different vessel types on a single system,
use of poorly manufactured economy
vessels, misalignment within the system,
and scratched or dirty vessels.
Use of mixed and/or economy vessels
is correlated to a higher coefficient of
variation (%CV) and failure rates. The
reason for this is that consistency of vessel
geometry is key to producing reproducible
hydrodynamics in each vessel, which
is required for reproducible dissolution
results. While the vast majority of vessels
available in the market meet USP <711>,
the spec for vessels is very wide allowing
different manufacturers to create vessels
in very different ways. When these vessels
are mixed, they often have different
volumes under the paddle or basket due
to the relationship of height, diameter, and
curvature from one vessel to another and
yield different results. Economy vessels
tend not to have the same level of quality
found in vessels direct from the apparatus
manufacturers, and will show a wider %CV
as well.
Scratched and dirty vessels can also cause
issues with altered hydrodynamics and
adsorption of drug onto the vessel.
Centering
Centering plays an important role in
maintaining hydrodynamics in the vessel;
therefore, centering devices must be in
2
good condition. For dissolution apparatus
with EaseAlign centering rings, all of the
“fingers” on the ring must be intact and the
O-rings within the EaseAlign ring must fit
tightly on the pegs in the vessel plate. This
will ensure proper centering of the vessel,
as well as maintain vessel verticality and
prevent vessel movement during a run. To
avoid variability, use only Agilent centering
rings as replacements.
EaseAlign centering ring systems can also
be upgraded with TruCenter conversion
kits, which have shown reduction in
variability due to superior centering and
verticality. The 708-DS, Agilent’s newest
dissolution apparatus, features TruAlign
vessels, which specifically address
centering and verticality and have shown
similar, if not improved, results to the
TruCenter vessels.
Deaeration
Deaeration continues to be a key
parameter, as it has been with previous
prednisone lots due to the sensitivity of
prednisone. Mix of passive and active.
Change to: The USP degassing procedure
outlined in <711> and the PVT Technical
Data sheet, or a validated alternative,
should be used. If using helium sparging
or an automated media preparation
station, the dissolved gas level should be
cross-checked with a dissolved gas meter
to show <6 ppm. Helium sparging is the
second most common degassing practice
in the industry, and it has been successful
with the current lot of prednisone tablets
when used properly. Helium sparging must
be validated against the USP degassing
procedure to ensure it is acceptable for
prednisone testing.
Care should also be taken in pouring of the
media once degassed. Media should be
poured gently to prevent reaeration. The
best practice would be to weigh media
directly into the vessel so that there is
only one pouring step – and better volume
accuracy is gained as well, which can
reduce %CV. Remember that volumetric
glassware may only be used at the
temperature at which it was calibrated and
graduated cylinders may not meet ± 1.0%
volumetric accuracy required by USP.
Continued on p. 8
The Disintegration Apparatus
Agilent 100
Automated
Disintegration
Apparatus
Conformance to compendia specifications
has and remains our top priority. The
International Conference on Harmonisation
(ICH), which harmonized the EP, USP
and JP, altered the disintegration
apparatus with changes that may require
customers to review their procedures to
ensure compliance with the harmonized
disintegration chapter found in USP 34
<701> Disintegration. Although the
procedures have changed slightly, the
Agilent 100 Disintegration Apparatus
remains unchanged since it is already
compliant with the new harmonized
procedure.
So what does this really mean? Your Agilent
100 still meets either specification for the
beaker dimensions and the disintegration
fluid volume is not stated in USP <701>
Disintegration. Although many procedures
may state that 900 mL should be used
for disintegration, this is not a compendia
requirement. The basket hanger and beaker
volume may easily be adapted to meet these
criteria.
The Agilent 100 is available in two
configurations, either a single-basket model
or the more versatile three-basket unit. This
self-contained system includes an integrated
water bath and circulator, and the drive
mechanism for the basket assemblies is
enclosed in the body of the instrument.
Continued on p. 7
Agilent’s TruAlign Dissolution Vessel – When Quality Counts
The ultimate goal of any dissolution test
is to determine the rate of release of
an active component into solution and,
possibly, detect batch or formulation
differences. As evidenced by recently
published materials from regulatory
agencies, it is becoming increasingly
important to control the physical
parameters, accessories, and techniques
related to the dissolution environment. One
critical component that plays a significant
role in determining dissolution results is
the vessel – and Agilent’s TruAlign vessel
provides a quality solution.
The TruAlign vessel, the standard vessel
used with the 708-DS Dissolution
Apparatus, serves to precisely align
the dissolution vessel every time. Once
installed in the vessel plate, the amount
of possible movement is negligible and
borderline detectable. This enables the
vessel to maintain accurate center and
verticality alignment with respect to the
dissolution apparatus. Each TruAlign vessel
is fitted with a collar incorporated onto
the vessel rim to protect the vessel and
facilitate safe handling. The collar also
includes a helpful indicator tab that allows
for reproducible vessel orientation each
time the vessel is installed.
The USP Performance Verification Test
(PVT) and ASTM and FDA Mechanical
Qualification (MQ) procedures both rely on
quality vessels for acceptable results. The
design, manufacturing, and consistency
of the TruAlign vessel have been shown to
provide a reduced Coefficient of Variation
(%CV) during the USP PVT for paddle
and basket tests. When verifying physical
parameters as part of the MQ, the stability
of the vessel ensures repeatable centering
and vessel verticality values. In both cases,
the indicator tab can be used to ensure the
same vessel orientation upon insertion.
See the difference in the quality and
reliability of Agilent’s newest vessels and
dissolution apparatus.
Link to online store: www.agilent.com/
lifesciences/vessel_ordering
The combination of the TruAlign vessel and
the 708-DS give the dissolution analyst
a clear advantage for achieving proper
results.
3
Dissolution Workstation Software – A “Greener,”
Compliant Approach to Dissolution Testing
Most laboratories performing dissolution
testing have procedures in place requiring
documentation of each step in the
process. This may involve test-specific
information about the product and
instrument, as well as real-time data for
every test. Oftentimes, this information
is manually transcribed in separate log
books, checklists, etc. One way to simplify
this process, increase data integrity,
reduce paperwork and become just a bit
“greener” is by implementing Agilent’s
Dissolution Workstation Software.
The Dissolution Workstation Software
provides complete, integrated control
of multiple dissolution systems (Agilent,
Varian or VanKel) from a single computer.
By utilizing this solution in an electronic
records environment, several aspects of
the dissolution test are documented and
controlled for less reliance on manual
transcription and improved recordkeeping. The software makes it possible
to implement the essential requirements
necessary for compliance in a 21 CFR Part
11 environment.
Setup and execution of dissolution tests
within the Dissolution Workstation
Software is a simple 2-step process.
Separate files are created and maintained
for the system configuration(s) and the
method(s). The configuration file contains
all relevant apparatus information
including serial numbers, accessory
IDs, and specific settings. The method
file stores all pertinent test parameters
such as sample timepoints, temperature,
speed, and volume(s). Each of these files
is created upon initial setup of the system.
For each subsequent test, it is only
necessary to select the appropriate system
and method to be executed. An additional
screen is made available before starting
the test for entering test-specific data,
as well as choosing one of the available
delayed start options.
Individual user rights and privileges are
controlled by the Dissolution Workstation
Software through leveraging the security
capabilities of the Windows ® operating
system. Several user groups exist that,
depending on the user’s credentials,
enable or disable features of the software
according to group membership. This
allows for a higher-level user to create the
system configurations and methods while
someone with lower-level rights can simply
run the necessary tests with no chance
of accidental setup errors. All changes to
any file within the software automatically
trigger the creation of a new version of
that file. The audit trail feature dynamically
determines the differences between two
or more versions and can display these in a
consolidated report.
The test report includes the method and
instrument identification, time/date of test,
real-time equipment data, and a complete
activity log of all events. The data is stored
within a database that may be created
locally or on a network. The client-server
architecture offers the potential to
integrate or export the data to a laboratory
information management system (LIMS).
Agilent’s complete line of dissolution
equipment is available for use with the
Dissolution Workstation Software. This
includes all Apparatus 1/2/5/6 models
(e.g., 708-DS), Apparatus 3/7 models
(e.g., BIO-DIS), and the associated
automated sampling equipment. Up
to four individual systems – even of
different models – may be connected to
a centralized PC to perform concurrent
dissolution tests.
Now, a solution is available to eliminate
the paper trail and streamline dissolution
testing in a compliant environment – let
the Dissolution Workstation Software work
for you.
All results generated with the Dissolution
Workstation Software can be previewed,
exported, digitally signed, and printed.
Method monitoring screen, visible during method setup
and testing.
Sample test report generated by the Dissolution Workstation
Software
Agilent 8453 Online UV Multicomponent Dissolution
chromatographic separation. Not only
are consumable costs kept to a minimum
(without HPLC columns, guard columns,
mobile phase constituents and disposal
costs) but filtration solutions may also
be less expensive with full flow filtration
rather than the 0.45µ filtration commonly
required for HPLC analysis.
Simple Calibration
Dissolution testing is typically quantified
with UV and HPLC analytical techniques.
While UV is often preferred during
analytical development due to its
flexibility, simplicity and cost savings, it
is traditionally used for single component
analysis only. HPLC may be chosen for
a variety of reasons including specificity
requirements and individual quantitation
of multiple active drugs, or the elimination
of interferences commonly seen in the
UV spectra. However, with modern
instrumentation yielding more precise
data and modern regression analysis
techniques, multiple component online
UV dissolution testing becomes feasible.
Agilent offers UV multicomponent
dissolution analysis through the strong
pairing of the Agilent 8453 UV-visible
spectrophotometer, 708-DS Dissolution
Apparatus and UV-visible ChemStation
software.
degradation. Online testing may be the
preferred route for some products that
could potentially decompose over time and
require additional handling, preservation,
or refrigeration. For these products it is
important that measurement be conducted
in real time during the dissolution test.
Post-run spectroscopic analysis or an
even slower HPLC analysis could produce
significant bias due to compromised
sample integrity. Rapid sampling coupled
with fast data acquisition and evaluation
makes real-time multicomponent analysis
possible.
Simplicity and Speed
UV multicomponent dissolution testing
provides solutions for obtaining valuable
information on multiple compounds in the
analytical development phase of dosage
forms, and the quality control process as
well. With high-quality multicomponent
analysis of dissolution samples,
determinations can be made quickly, with
numerous timepoints, and may reduce the
cost of drug development without a loss of
analytical integrity.
Spectroscopic methods of analysis have
an advantage of simplicity and speed
compared to chromatographic methods.
With diode array analysis, dissolution
samples may be taken as often as every
minute. Numerous data points can be
acquired and charting can be completed
for critical profile attributes, even for
immediate release products. Burst phases
may also be adequately captured with
multiple data points in the early stages
of extended and controlled release of
multiple drug products. Analytical R&D
areas may benefit from quick turnaround
time afforded by online analysis, which
yields data at the end of the dissolution
test to expedite review, decision making
and time to market.
Real-Time Analysis
Economic Alternative
A key benefit of real-time analysis may
be realized with multiple drug dosages
where one or more products undergo
Calibration is simple and fast using pure
standards or mixtures of standards.
Statistics for the fit of the standards to
the sample spectra give you confidence in
your results. With modern instrumentation
yielding more precise data and modern
regression analysis techniques available
within ChemStation, multiple component
online UV dissolution testing becomes
feasible. The algorithms provided are linear
least squares fits and maximum likelihood
fits. The maximum likelihood algorithm
uses statistical information available for
each individual data point in the acquired
spectra.
Multicomponent dissolution analysis
may be viewed as a cost-saving
solution compared to the higher cost of
Multicomponent analysis with diagnostic tools that show the
quality of the results.
In summary, your ability to perform
multicomponent dissolution analysis
of known and investigative active drug
substances will provide additional data
points at critical stages of release without
a loss of specificity, accuracy or precision.
Simultaneous acquisition, sophisticated
regression analysis, excellent wavelength
reproducibility, and the ability to obtain
instant spectral absorbance data over
the entire wavelengths range provide the
analyst with a superior tool for dissolution
analysis. Please visit the Agilent website
or contact us for information pertaining
to online multicomponent dissolution
analysis.
5
Dissolution and Vibration
Using the QAII C, you can take several
different measurements, including wobble
and RPM measurement (left) and vibration
measurement (right).
There has been considerable controversy
regarding the qualification of dissolution
apparatus since dissolution laboratories are
now confronted with two sets of standards
concerning the performance qualification
of the apparatus; the traditional USP
Performance Verification Test (PVT) with
prednisone tablets and the new Enhanced
Mechanical Calibrations (or Mechanical
Qualification, (MQ) standards from FDA
and ASTM. The primary focus of both
practices is to provide a suitable apparatus
and environment conducive to providing
accurate results with minimum variability.
Each stresses the detection and elimination
of accuracy and precision issues arising
from the apparatus or its environment
to ensure the quality and integrity of
dissolution results.
The traditional USP PVT is a holistic
method for detecting perturbation within
the dissolution apparatus. In the presence
of vibration, prednisone release rates may
fail the limits for geometric mean or %CV.
The USP test is somewhat analogous to
the check engine light that may illuminate
on your automobile instrument panel
when something is wrong. You really don’t
know exactly what is wrong, but you need
to check it out, isolate the source of the
problem and fix it. In this regard, a failed
PVT result indicates a problem that needs
further investigation for the source of the
problem and then a solution implemented,
including a corrective action to keep the
problem from reoccurring. Vibration may
be a difficult issue to diagnose, especially
after a dissolution run is complete.
The Enhanced MQ procedures which
target individual perturbance are a bit less
precise with regard to vibration. Although
the original PhRMA studies indicated that
6
the USP PVT should be maintained until
there is a suitable vibration specification,
there has not been a suitable vibration
measurement, specification or tolerance
developed at the time of this writing. The
ASTM and FDA procedures, have been
acknowledged as suitable alternatives for
qualification of the dissolution apparatus
by the FDA Guidance for Industry. The
Guidance states “that appropriate
measures be taken to control the
following sources of significant variability
in dissolution testing: dissolved gasses,
vibration and vessel dimensions.” Although
a meaningful vibration tolerance and
specification has yet to be developed, an
FDA collaborative study, in which Agilent
is participating, is working to identify the
definitive parameters of vibration and set a
specification and tolerance. Since the limit
has yet to be determined, the best practice
at the time is elimination of sources of
vibration which may affect dissolution
apparatus.
While there are various means of detecting
vibration, including Agilent’s QAII C
Mechanical Qualification Station, it is
essential that the dissolution environment
is free of sources of vibration. This
not only reduces the risk of impact on
dissolution results which generally may
make products dissolve faster, but it
increases the reliability of the apparatus to
generate results that support the integrity
of the performance test. The approach to
detecting vibration issues may be slightly
different, but the primary goal of providing
good results is best accomplished by
investigating these three areas:
Location of the Dissolution
Laboratory
The location of the dissolution laboratory
is essential for its ability to produce
dissolution testing results that are not
influenced by vibration. The location
surrounding the dissolution laboratory
should be free from non-analytical sources
of vibration routinely found around
and adjacent to the laboratory such as
slamming doors, stairwells, elevators,
process equipment, and forklift traffic.
Dissolution may be greatly affected by
sources immediately outside your facility,
such as heavy machinery, highway or
building construction, railroads, parking
decks and garages. Occasionally,
dissolution laboratories must be relocated
or suspend testing during periods of
construction.
Remove all Sources of Vibration
Dissolution apparatus are best kept away
from other analytical instrumentation and
sample preparation equipment. For the
same reasons that we isolate balances
from vibration, we should use a similar
rationale for dissolution apparatus.
Immediate sources of vibration typically
found in the laboratory are fume hoods,
ultrasonic baths, orbital and wrist-action
shakers, mixers, centrifuges, vacuum
pumps, tapped density equipment and
even other analytical equipment such as
GCs and HPLCs and certain computers
and printers. Agilent qualification chemists
have even observed a radio perched on top
of a dissolution apparatus playing music
with heavy bass, clearly contributing to
vibration issues.
Continued on p. 7
Dissolution and Vibration: continued from p. 6
Disintegration Apparatus: continued from p. 2
Both units are microprocessor controlled
for setting up a test and leaving it
unattended. At the end of the designated
testing time, the basket is suspended
from the media so you can check for any
residual tablet material. The three-basket
model allows for three independent tests
to be performed simultaneously, as each
basket can be independently programmed.
QAIIC vibration sensor
Internal Sources of Vibration
Regular preventative maintenance
procedures should be in place to routinely
check for vibration within the dissolution
apparatus, including the condition and
placement of the heater/circulator. Routine
maintenance should include the removal
of the top cover to check the belt for
performance issues such as missing teeth,
belt wear, and a loose belt, pulleys or
spindles. A slight dusting of black rubber
is common in most apparatus and may
not cause a problem unless the belt is
exhibiting excessive wear. The heater/
circulator should never directly touch the
dissolution apparatus unless it features
isolators to shield the apparatus from
vibration.
In summary, whether a vibration
specification is in place or not, the best
remedy for eliminating the influence
of vibration is to remove all sources of
vibration from the dissolution environment.
The USP PVT cites the sensitivity of
prednisone to several parameters,
including vibration, to alert the user that
conditions for dissolution testing may
be unacceptable. Although existing
mechanical qualification parameters and
enhanced parameters may be used to tune
the apparatus to reduce variability, the
analyst is still responsible for addressing
issues that are not directly addressed by
with the enhanced mechanical qualification
procedures, such as the condition of
vessels, the presence of vibration and
deaeration.
and single-tube baskets for larger dosage
forms such as those required for veterinary
products. Agilent also offers disintegration
beakers and cylindrical disks required for
conformance to compendia specifications,
an assortment of mesh screen sizes, and
individually measured verified components
with NIST-traceable equipment that are
documented for conformance verification.
In addition to the standard six-tube
basket assembly, we offer three-tube
Pre-Harmonization Requirements
from USP <701> Disintegration:
“The apparatus consists of a basket-rack
assembly, a 1000-mL, low-form beaker,
138 to 155 mm in height and having an
inside diameter of 97 to 110 mm for the
immersion fluid”
“The volume of the fluid in the vessel
is such that at the highest point of the
upward stroke the wire mesh remains
at least 2.5 cm below the surface of the
fluid and descends to not less than 2.5
cm from the bottom of the vessel on the
downward stroke.
Post-Harmonization Requirements
from USP <701> Disintegration:
“The apparatus consists of a basket-rack
assembly, a 1000-mL, low-form beaker,
138 to 160 mm in height and having an
inside diameter of 97 to 115 mm for the
immersion fluid”
“The volume of the fluid in the vessel
is such that at the highest point of the
upward stroke the wire mesh remains
at least 15 mm below the surface of the
fluid and descends to not less than 25
mm from the bottom of the vessel on the
downward stroke. At no time should the
top of the basket-rack assembly become
submerged.”
Underlined values indicate changes from Pre- to Post-Harmonization Requirements
Disintegration baskets and accessories
1ASTM E2503-07, Standard Practice for Qualification of Basket and
Paddle Dissolution Apparatus, 2007
2FDA DPA-LOP.002, Mechanical Qualification of Dissolution
Apparatus 1 and 2, Version # 2.0, Effective June 2, 2006
3FDA Guidance for Industry, The Use of Mechanical Calibration of
Dissolution Apparatus 1 and 2 – CGMP, January 2010. www.fda.
gov/downloads/Drugs/.../Guidances/UCM198649.pdf
7
Critical Path: continued from p. 2
Improper Sampling and Filtration
The USP sampling zone is the area in the
vessel which is the most reproducible
and allows for representative sampling.
Sampling and filtration of samples needs to
occur within a 2% window of a timepoint
per USP. Sampling or filtering outside of
this window allows dissolution to continue,
causing higher and more variable results.
We recommend the use of Agilent’s Full
Flow Filters, which filter as you are pulling
a manual sample and save valuable time
compared to using a syringe disk filter.
Also, automated sampling should not be
used for the PVT, unless it has already been
validated. Due to hydrodynamic disturbance
created, resident probes should not be used
in the qualification procedure.
off-center landing can often result in the
prednisone tablet forming an off-center
cone, which then redistributes as a cone
in the center of the vessel. Due to the high
shear rate just outside the calm center of
the vessel the prednisone particles may be
rapidly distributed into the media and exhibit
a rapid rate of dissolution, usually about
3-5% faster, leading to different results than
tablets that initially landed in the center.
To prevent off-center landing, do not stir the
vessels for media equilibration at least two
minutes prior to the start of the run. Even
once the paddles are stopped, the media
will continue to rotate and will give a greater
chance for the tablet to land off-center.
Tablet Positioning
When dropped into the vessel, prednisone
should settle at the bottom-center of the
vessel to ensure proper dissolution. An
Americas Field Support Center
2850 Centerville Road
Wilmington, DE 19808
Learn more:
www.agilent.com/lifesciences/dissolution
8
This information is subject to change without notice.
© Agilent Technologies, Inc. 2011
Printed in U.S.A., June 2011
5990-7913EN
Agilent chemists are always available
to assist you with dissolution questions.
Should you require assistance with
performing and passing the PVT, feel
free to contact our Dissolution Hotline at
[email protected].