Journal of Ravishankar University–B, 31
(1), 32-39 (2018)
Key Aspects of Analytical
Method Development and Validation
Suman Shrivastava, Pooja Deshpande, S. J. Daharwal*
University Institute of
Pharmacy, Pt. Ravishankar Shukla University, Raipur-492010, Chhattisgarh, India.
*Corresponding Author: firstname.lastname@example.org
[Received: 20 February 2018; Revised
version: 08 April 2018; Accepted: 13 April 2018]
Abstract: Development of a method is crucial for discovery,
development, and analysis of medicines in the pharmaceutical formulation. Method
validation could also be thought to be one in all the foremost well-known areas
in analytical chemistry as is reproduced within the substantial variety of
articles submitted and presented in peer review journals every year. Validation of an analytical procedure is to
demonstrate that it's appropriate for its intended purpose. Results from method
validation are often wont to decide the quality, reliability and consistency of
analytical results. Analytical methods need to be validated or revalidated.
This review describes general approach towards validation process and
validation parameters to be considered during validation of an analytical
method. It also refers to various regulatory requirements like WHO, USFDA,
EMEA, ICH, ISO/IEC. The parameters described here are according to ICH guidelines
which include accuracy, precision, specificity, limit of detection, limit of quantification,
linearity range and robustness.
Keywords: Method development; Validation; Analytical method; ICH
guidelines; Accuracy and precision.
vital in any product or service, and it is also important in drug because it
involves life (Hema and Reddy, 2017). Analytical chemistry is the analysis of
separation, quantification and chemical additives identification of herbal and
synthetic materials constituted with one or more compounds or factors.
Analytical chemistry is separated into two predominant classes, a qualitative
evaluation that is to say the identification with regard to the chemical
additives exists in the sample, whereas quantitative evaluation estimates the
amount of positive detail or compound within the substance, i.e. the sample
(Ravisankar et al., 2015). The consistency of an analytical finding could be a
matter of great importance to drive the formulation scientist in the developing
stage and impurity profile in stability study and dissolution data of the
stability study yet as routine analysis. The importance of validation is
producing reliable and repeatable results for routine analysis and stability
analysis. This is often very true within the context of quality management and certification,
that became matters of increasing importance in analytical in dissolution and
impurity profile within the recent years. Therefore, this subject ought to
extensively be mentioned on an international level to achieve a harmony on the
extent of validation experiments and on acceptance criteria for validation
parameters of analytical methods (Thompson et al., 2012).
In pharmaceutical industry, Validation
is an important part of quality control and quality assurance. Various
regulatory authorities offer special importance on the validation of all the
processes used in the industry. Validation may be formal and systematic way to
demonstrate suitability of the method to provide helpful information to confirm
that the method or the method gives satisfactory and consistent results among
the scope of the method. The analytical methods refer to the manner of
performing the analysis. “Validation is that the method by that it is
established by laboratory studies, that the performance characteristics of the
method meet the requirements for the intended application” (Chan, 2010; Huber,
2007). All the analytical methods that are meant for analyzing any sample got
to be valid. The current good manufacturing practices suggest that quality
should be built into the product, and testing alone cannot be relied on to
ensure product quality. Pharmaceutical products got to maintain prime quality
so as to supply safe and effective usage. From the analytical purpose of interpretation,
analytical methods used to test these products should have quality attributes
built into them. Validation ensures these quality attributes are built into the
method. Validation of analytical methods is a vital but time-consuming activity
for most analytical laboratories. But it results inexpensive, eliminates
frustrating repetitions and leads to better time management in the end. The
analytical methods need to be validated or revalidated before initial use of
the method in routine analysis, when transferred from one laboratory to
another, whenever the conditions or method parameters that technique has
been valid amendment and alter is outside the initial
scope of the method (Paithankar, 2013).
validation is that the method used to ensure that the analytical procedure
utilized for a selected check is appropriate for its meant use. Results from
method validation may be able to decide the quality, reliability, and
consistency of analytical results; it is an essential part of any good
methods need to be validated or revalidated.
i. Before their introduction
into routine use
the conditions change for which the method has been validated (e.g., an
instrument with different characteristics or samples with a different matrix);
the method is changed, and the change is outside the original scope of the
method (Patil et al., 2017).
validation has received significant attention within the literature and from
industrial committees and regulatory agencies.
guidelines on Analytical Procedure development: The new
guideline is proposed for harmonising the scientific approaches of Analytical
Procedure Development, and providing the principles relating to the description
of Analytical Procedure Development process. Applying this guideline can improve regulatory
communication between industry and regulators and facilitate additional
economical, sound scientific and risk-based approval further as post-approval modification
management of analytical procedures (ICH Q14, 2018).
on Analytical Method Validation: This presents some information on the
characteristics that should be considered during validation of analytical
methods. Approaches other than those specified may be followed and may be
acceptable. Manufacturers should choose the validation protocol and procedures
most suitable for testing of their product. The manufacturer should demonstrate
that the analytical procedure is suitable for its intended purpose. Analytical
methods, whether or not they indicate stability, should be validated. The
analytical method should be validated by research and development before being
transferred to the quality control unit when appropriate. The recommendations
as provided for in good laboratory practices and guidelines for transfer of
technology should be considered, where applicable, when analytical method
validation is organized and planned (Guidelines on validation, 2016).
Q2R1 and EMEA guidelines on Validation of Analytical Procedures: This document
presents a discussion of the characteristics for consideration during the
validation of the analytical procedures included as part of registration
applications submitted within the EC, Japan and USA. This document does not
necessarily seek to cover the testing that may be required for registration in,
or export to, other areas of the world. Furthermore, this text presentation
serves as a collection of terms, and their definitions, and is not intended to
provide direction on how to accomplish validation. These terms and definitions
are meant to bridge the differences that often exist between various compendia
and regulators of the EC, Japan and USA. The objective of validation of an
analytical procedure is to demonstrate that it is suitable for its intended
purpose. A tabular summation of the characteristics applicable to identification,
control of impurities and assay procedures is included. Other analytical
procedures may be considered in future additions to this document (ICH Q2R1,
2005; EMEA, 1996).
ISO/IEC 17025 includes a
chapter on the validation of methods with a list of nine validation parameters.
The International Conference on Harmonization (ICH) has developed a consensus
text on the validation of analytical procedures. The document includes
definitions for 8 validation characteristics. ICH also developed a guidance with
the detailed methodology (ISO, 2005). The US EPA prepared guidance for
method’s development and validation for the Resource Conservation and Recovery
Act (USEPA, 1995). The FDA has also published guidance for the
validation of bioanalytical methods (USFDA, 2001).
method development: When there are no definitive
techniques are present, new methodologies are being progressed for evaluation
of the novel product. To investigate the presence of either pharmacopoeial or
non-pharmacopoeial product novel techniques are developed to reduce the value
besides time for higher precision and strength. These methodologies are
optimized and valid through preliminary runs. Alternate ways are planned and
place into practice to exchange the present procedure within the comparative
laboratory information with all accessible merits and demerits (Chauhan et al.,
method development: Drug
evaluation exhibits the identity characterization and resolution of the drugs
in combination like dosage forms and organic fluids. At some point of producing
technique and development of drug the principal purpose of analytical
strategies is to generate data regarding efficiency (which might be directly
connected with the need of a identified dose), impurity (related to safety of
the medication), bioavailability (consists of key drug traits like crystal
kind, uniformity of drug and release of drug), stability(that shows the
degradation product), and effect of manufacturing parameters to verify that the
production of drug product is steady (Sharma et al., 2018).
reasons for the development of novel methods of drug analysis are:
there is no official drug or drug combination available in the pharmacopoeias.
there is no decorous analytical process for the existing drug in the literature
due to patent regulations.
there are no analytical methods for the formulation of the drug due to the
interference caused by the formulation excipients.
methods for the quantitation of the analyte in biological fluids are found to
existing analytical procedures may need costly reagents and solvents. It may
also involve burdensome extraction and separation procedures.
Steps for the
development of the method: Development procedure follows with the proper
documentation. All data relating to these studies must be recorded either in
laboratory notebook or in an electronic database (Ravisankar et al., 2015).
All known important information about the analyte and its structure that is to
say physico-chemical properties like solubility, optical isomerism etc., is
The standard analyte (≈100 % purity) is obtained. Necessary arrangement is to
be made for the perfect storage (refrigerator, desiccators, and freezer).
In the sample matrix when multiple
components are to be analyzed, the number of components is noted duly
presenting the data and the accessibility of standards is estimated.
Methods like spectroscopic, HPLC, GC, MS
etc., are considered when matched with the sample stability (Ravisankar et al., 2015).
requirements of the analytical method need to develop the analytical figures of
merit such as linearity, selectivity, range, accuracy, precision, detection
limits etc., shall be defined (Ravisankar et
search and prior methodology: All the information of literature
connected with the drug is reviewed for physico-chemical properties, synthesis,
solubility and appropriate analytical methods with reference to relevant books,
journals, USP/NF, AOAC and ASTM publications and it is highly convenient to
search Chemical Abstracts Service automated computerized literature (Ravisankar et al., 2015).
a) Duly utilizing the information
available from the literature, methodology is evolved since the methods are
changed wherever required. Occasionally it is imperative to get additional
instrumentation to develop, modify or reproduce and validate existing
procedures for analytes and samples.
If there are no past suitable methods available to analyze the analyte to be
examined (Ravisankar et al., 2015).
setup and initial studies: Installation, operational and performance
qualification of instrumentation with reference to laboratory standard
operating procedures is verified by setting up appropriate instrumentation (Ravisankar et al., 2015).
performing optimization, one parameter is changed at a time and a set of
conditions are isolated, before utilizing trial and error approach. The said
work need to be accomplished basing on a systematic methodical plan duly
observing all steps and documented with regard to dead ends (Ravisankar et al., 2015).
analytical figures of merit: The actual decided analytical figures of
merit like Limit of quantitation, Limit of detection, linearity, time taken for
analysis, cost, preparation of samples etc. are also documented (Ravisankar et al., 2015).
development method with real samples: The sample solution should lead to
unequivocal, total identification of the peak interest of the drug apart from
all other matrix components (Ravisankar et
percent recovery of real samples and demonstration of quantitative sample
Percent recovery of spiked, genuine standard drug into a sample matrix which
contains no analyte is estimated. Optimization to reproducibility of recovery
(average ± standard deviation) from sample to sample has to be showed. It is
not necessary to get 100% recovery so far as the results are reproducible to
recognize with a high degree of certainty (Ravisankar et al., 2015).
of an analytical approach is established through laboratory research, that the
execution attributes of the procedure meet the requirements for the proposed
scientific application. Validation is required for any new or altered procedure
to verify that it is fit for giving predictable and dependable outcomes, once used
by various administrators by usage of comparable instrumentation inside the
similar or absolutely distinct laboratories (Bhardwaj et al., 2015).
process of validation of analytical method is adopted to confirm that the
employed analytical procedure for a specific test meet the intended
requirements. Guidelines from the USP, ICH, FDA etc., can provide a framework
for validations of pharmaceutical methods. Results from the method validation
can be considered to judge its quality, reliability as well consistency pertaining
to analytical results. In the realm of pharmaceutical industry, the prominent
reasons for validating assay are the first crucial one is validation of assay
which is the integral part of the quality-control system and secondly
regulation of genuine manufacturing practices inevitably needs assay validation
(USP, 2000; USFDA).
Importance of validation (Nandhakumar et
al., 2011; Bansal et al., 2004; Jenke, 1996)
Assurance of quality
Reduction of quality cost.
Nominal mix-ups, and bottle necks
Minimal batch failures, improved efficiently and
Reduction in rejections.
Avoidance of capital expenditures
Fewer complaints about process related failures.
Reduced testing in process and in finished goods.
More rapid and reliable start-up of new equipment
Easier scale-up form development work.
Easier maintenance of equipment.
Improved employee awareness of processes.
More rapid automation.
Government regulation (Compliance with validation
requirements is necessary for obtaining approval to manufacture and to
introduce new products)
for the validation of methods: The validity of a specific method
should be demonstrated in laboratory experiments using samples or standards
that are similar to unknown samples analyzed routinely. The preparation and
execution should follow a validation protocol, preferably written in a
step-by-step instruction format. This proposed procedure assumes that the
instrument has been selected, and the method has been developed. It meets
criteria such as ease of use; ability to be automated and to be controlled by
computer systems; costs per analysis; sample throughput; turnaround time; and
environmental, health, and safety requirements (Patil et al., 2017).
in Method Validation: (CITAC/EURACHEM,
a validation protocol, an operating procedure or a validation master plan for
a specific validation, project defines owners and responsibilities
a validation project plan
the application, purpose, and scope of the method
the performance parameters and acceptance criteria
relevant performance characteristics of equipment
materials, for example, standards and reagents for purity, accurate amounts,
and sufficient stability
method parameters or/and acceptance criteria if necessary
full internal (and external) validation experiments
SOPs for executing the method in the routine
criteria for revalidation
type and frequency of system suitability tests and/or analytical quality
control checks for the routine
validation experiments and results in the validation report.
of analytical procedures to be validated:
discussion of the validation of analytical procedures is directed to the four
most common types of analytical procedures:
tests for impurities' content;
tests for the control of impurities;
tests of the active moiety in samples of drug substance or drug
or other selected component(s) in the drug product.
Identification tests are intended
to ensure the identity of an analyte in the sample. This normally achieved by
comparison of a property of the sample (e.g., spectrum, chromatographic behaviour,
chemical reactivity, etc) to that of a reference standard. Testing for
impurities can be either a quantitative test or a limit test for the impurity
in a sample. Either test is intended to accurately reflect the purity
characteristics of the sample. Different validation characteristics are
required for a quantitative test than for a limit test. Assay procedures are
intended to measure the analyte present in a given sample. In the perspective
of this document the assay presents a quantitative measurement of the major
components in the drug substances.
the drug products similar characteristics also apply when assaying for the
active or other selected components. The same validation characteristics also
apply to assay associated with other analytical procedures (Lavanya et al., 2013).
method validation parameters
The parameters for validation as per ICH
guidelines (ICH, 2005) need to be selected as per the regulatory requirements.
The parameters considered in chromatographic method validation are discussed
Figure 1. Validation
is the ability to assess the analyte for the presence of various components
that may be present. It can be established by a number of approaches, depending
on the intended purpose of the method. The ability of the method to assess the
analyte of interest in a drug product is determined by a check for interference
by placebo. Specificity can be assessed by measurement of the API in samples
that are spiked with impurities or degradants.
API-related compounds are not available, drug can be stressed or force-degraded
in order to produce degradation products. In chromatographic separations,
apparent separation of degradants may be confirmed by peak purity
determinations by photodiode array, mass purity determinations by mass
spectroscopy (MS) or by confirming separation efficiency using alternate column
chemistry. Lack of specificity of an individual analytical procedure may be
compensated by other supporting analytical procedures (ICH, 2005).
term selectivity is sometimes used interchangeably with specificity.
Technically, however, there is a difference. Selectivity is defined as the
ability of the method to separate the analyte from other components that may be
present in sample, including impurities. Selectivity is separate and shows
every component in the sample. Therefore, one could have a method that is
specific, yet it may not be selective (Shrivastava and Gupta, 2012).
linear relationship should be evaluated across the range (see section 3) of the
analytical procedure. It may be demonstrated directly on the drug substance (by
dilution of a standard stock solution) and/or separate weighing of synthetic
mixtures of the drug product components, using the proposed procedure. The
latter aspect can be studied during investigation of the range. Linearity
should be evaluated by visual inspection of a plot of signals as a function of
analyte concentration or content. If there is a linear relationship, test
results should be evaluated by appropriate statistical methods, for example, by
calculation of a regression line by the method of least squares. For the
establishment of linearity, a minimum of 5 concentrations is recommended (ICH,
2005; Araujo, 2009).
accuracy of an analytical procedure expresses the closeness of agreement
between the value which is accepted either as a conventional true value or an
accepted reference value and the value found. This is sometimes termed trueness
and several methods available of determining the accuracy. Accuracy should be
established across the specified range of the analytical procedure. Accuracy
should be assessed using a minimum of 9 determinations over a minimum of 3
concentration levels covering the specified range (e.g., 3concentrations/3
replicates each of the total analytical procedure). Accuracy should be reported
as percent recovery by the assay of known added amount of analyte in the sample
or as the difference between the mean and the accepted true value together with
the confidence intervals (Srivastava and Kumar, 2017).
precision of an analytical procedure expresses the closeness of agreement
(degree of scatter) between a series of measurements obtained from multiple
sampling of the same homogeneous sample under the prescribed conditions. It can
be sub divided into repeatability, intermediate precision and reproducibility.
Precision should be investigated using homogeneous, authentic samples. However,
if it is not possible to obtain a homogeneous sample it may be investigated
using artificially prepared samples or a sample solution. The standard
deviation, relative standard deviation like coefficient of variation and
confidence interval should be reported for each type of precision investigated.
Repeatability: Repeatability is
also termed intra assay precision. Repeatability is the variation experienced
by a single analyst on a single instrument. Repeatability does not distinguish
between variation from the instrument or system alone and from the sample
preparation process. During the validation, repeatability is performed by
analyzing multiple replicates of an assay composite sample by using the
analytical method. Repeatability should be assessed using a minimum of 9
determinations covering the specified range for the procedure by 3 replicates
or 6 determinations at 100% of the test concentration (Daksh et al., 2015).
Intermediate precision expresses within-laboratories variations: different
days, different analysts, different equipment, etc. Intermediate precision
depends upon the circumstances under which the procedure is intended to be
used. The applicant should establish the effects of random events on the
precision of the analytical procedure. Typical variations to be studied include
days, analysts, equipment, etc. It is not considered necessary to study these
effects individually. The use of an experimental design (matrix) is encouraged.
A statistical comparison is made to the first analyst’s results (Daksh et al., 2015).
expresses the precision between laboratories (collaborative studies, usually
applied to standardization of methodology). Reproducibility is assessed by
means of an inter-laboratory trial (Tijare et
quantity of an analyte which may be detected by the chromatographical
separation however it is not necessary that this quantity will quantify as a
precise value. A blank resolution is injected and peak to peak quantitative
noise relation we have to calculate from blank chromatograms. Then, calculate
the concentration at the signal to quantitative noise relation is concerning
can be expressed as
LOD = 3.3 σ /S
σ = Standard deviation of response, S = Slope of calibration curve (Pasbola and Chaudhary, 2017).
slope S may be estimated from the calibration curve of the analyte. The
estimate of σ may be carried out in a variety of ways, based on the standard
deviation of the blank and the calibration curve.
Quantitation limit of an individual analytical procedure is the lowest amount
of analyte in a sample which can be quantitatively determined with suitable
precision and accuracy. The quantitation limit is a parameter of quantitative
assays for low levels of compounds in sample matrices, and is used particularly
for the determination of impurities and/or degradation products. It can be
determined visually, by signal to noise ratio, standard deviation of the
response and the slope. Quantitation limit signal to noise approach can only be
applied to analytical procedures which exhibit baseline noise. Comparing
measured signals from samples with known concentrations of analyte with those
of blank samples and establishing the minimum concentration at which the analyte
can be reliably detected. A signal-to-noise ratio between 10 or 10:1 is
generally considered acceptable for estimating the quantitation limit.
quantitation limit may be expressed as
LOQ=10 σ/ S
σ=Standard deviation of the response, S= Slope of the calibration curve.
slope S may be estimated from the calibration curve of the analyte. The
estimate of σ may be carried out in a variety of ways, based on the standard
deviation of the blank and the calibration curve. The LOQ level is usually
confirmed by injecting standards which have an acceptable percent relative
standard deviation (% RSD) not more than 10% (ICH, 2005; Geetha et al., 2012).
evaluation of robustness should be considered during the development phase and depends
on the type of procedure under study. It should show the reliability of an
analysis with respect to deliberate variations in method parameters. If
measurements are susceptible to variations in analytical conditions, the
analytical conditions should be suitably controlled or a precautionary
statement should be included in the procedure. One consequence of the
evaluation of robustness should be that a series of system suitability
parameters (e.g., resolution test) is established to ensure that the validity
of the analytical procedure is maintained whenever used (ICH, 2005; Ajay and
is the degree or measure of reproducibility under different situations such as
in different laboratories, different analyst, different machines, environmental
conditions, operators etc (Boque et al.,
suitability test is used to check the sensitivity, resolution, and
reproducibility of the chromatographic system are well for the analysis to be
done. The factors mainly used in system suitability are tailing factor, a
number of the theoretical plate, retention time, resolution, etc. (Gupta et
al., 2012; Sanap et al., 2017).
article gives an idea that what is validation, its types, why it is necessary,
how to develop a method and how to carry out the validation procedure to
demonstrate that the technique is able for its proposed reason. All validation
parameters such as linearity, LOQ, LOD, Range, specificity, robustness,
ruggedness and system suitability are defined.
authors are grateful to Director, University Institute of Pharmacy, Raipur for
providing encouragement and critical review on the manuscript.
is no conflict of interest from the authors.
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