An introduction to analytical method validation

Mr. Bhavadip B. Tanna

For Pharmaceutical drug analysis analytical method validation is very important parameter. So, there is a need for the study of validation parameters.

The analytical procedure refers to the way of performing the analysis. Analytical method validation is required for herbal procedure,new process and reaction,new molecules, active ingredients,residues, impurity profiling and component of interest in different matrices.An analytical methodology consists of the techniques,method , procedure and protocol.this methodology the required data for a given analytical problem, required sensitivity,required accuracy,required range of analysis and required precision to the analyst.It is required for assuring quality,achiving acceptance of products by the international agencies, mandatory requirment purposes for accreditation as per ISO 17025 guidelines,mandatory requirment for registration of any pharmaceutical product or pesticide formulation.The main objective is to demonstrate that the procedure is suitable for its intended purpose.the method validation studies for the developed methods for various parametersas per protocol and guidelines which are EN 45000 series of standards,ISO\ IEC Guide 25, Internation conference on harmonization (ICH) , US EPA, USP, published litreture.There are 4 types of analytical procedures which includes identification testes, impurity tests, limit tests and potency tests.Identification testes which normally compares that sample under evalution with a known reference sample standard with spectrographic or chromatographic methods. Impurity tests may be either quantitative or limit test and different validation requirements applied. For limit testes, specificity and detection limits only may required.For assay of actives or other key components of drug products potency tests is performed.

The validation parameters that should be considered during validation of analytical procedures are shown as:

§ Specificity: It conforms the ability of the methods to evalute the desired analyte in the presence of known other components like degradants, impurities, potential contamination and excipients.It is not possible to demonstrate that an analytical procedures is specific for a particular analyte. In such case a combination of two or more analytical procedure is recommended to achieve the necessary level of discrimination.lack of specificity of an individual analytical procedure may be compensated by other supporting analytical procedures or tests.

§Accuracy: The accuracy of analytical procedure expresses the closeness of agreement between the values which is accepted either as conventional true value or an accepted reference value in the value found which is sometimes called as trueness.It should be established across the specified range of procedure.

§ Precision: The procedure 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 condition.

It may be considered at 3 levels:

~~Repeatability: It expresses the precision under the same operating conditions over a short interval of time .It is also known as inta-assay precision.

~~Inter mediate precision: It express within laboratory variations like different analysts, days and equipments.

~~Reproducibility: It expresses the precision between laboratories.There are variations like differences in room temperature and humidity, operating with different expertience and thoroughness,variation in material and instrument condition , equipment and consumable of different ages affecting a method’s reproducibility.

§ Limit of Detection (LOD): The detection of an individual analysis procedure is the lowest amount of analyte in a sample which can be detected but not necessarily quantify as an exact value. It may be determined by the analysis of sample with known concentrations of the analyte and by establishing the minimum level at which the analyte can be reliably detected.

Based on standard deviation of the response and the slope it is shown as:

DL= 3(SD/Slope)

§ Limit of quantification(LOQ) :The quantification limit of an individual analytical procedure is the lowest amount of analyte in a sample which can be quantitatively determine with suitable precision and accuracy .It is used particularly for the determination of impurities and degradation products. It is shown as:

DL=10(SD/Slope)

§ Linearity : The linearity of an analytical procedure is its ability to obtain test results which are directly propotional to the concentration of analyte in the sample.Minimum 5 concentrations are recommended for the establshiment of linearity.

§ Range: The range of an analytical procedure is the interval between the upper and lower concentration of analyte in the sample for which it has been demonstrated that the analytical procedure has a suitable level of precision , accuracy and linearity.

§ Robustness : The robustness of analytical procedure is a measure of Its capacity to remain unaffected by small,but deliberate variations(e.g.stability of analytical solutions, extraction time ,etc.) in method parameters and provide an indication of its reliability during normal usage.

§ System Suitability Testing: It is an integral part of many analytical procedure.The tests are based in the concept that equipment electronics , analytical operations and sample to be analysed constitute an integral system that can be evaluated as such.

Revalidation:

operating ranges should be defined for each method based on experience with similar methods. The availability of such operating ranges makes it easier to decide when a method should be revalidated.It is necessary whenever a method is changed and the new parameters is outside the operating range.For example , a revalidation is necessary if a high –performance liquid chromatography method has been developed and validated on a pump with a delay volume of 5ml and the new pump only has 0.5ml

Conclsion:

The efficient development and validation of analytical methods are critical element in the development of pharmaceuticals. Success in this area can be attributed to several important factors,which in turn will contribute to regulatory compliance.A strong mmenotering and training program is an important factor for ensuring successful methods development and validation.

References:

1. http://www.shriraminstitute .org

2. S.Iyer; “Guidelines on cGMP AND QUALITY OF PHARMACEUTICAL PRODCUCTS”; D. K. publications; First Edition ; January 2003 ; pg no. 145-157

3. Sidney H. Willing and James R. Stokar; “Good Manufacturing Practices for Total Quality Control”; Fourth Edition, Revised and expanded; MARCEL DEKKER INC.; 141-143

4. World Health Organization – Geneva “ Quality assurance of Pharmaceutical – A Compendium of guidelines and related materials”; Pharma Book Syndicate ; Volume -1 ; 119-123

5.Robert A. Nash and Alfred H. Wachter ; “ Pharmaceutical Process Validation; An International Third Edition ‘ Revised and expanded ; MARCEL DEKKER INC.; 507-522

6.http://www.who.org

7. http://www.fda.gov/cder/guidance/4252fnl.htm

8. http://www.pharmatech.com

About Authors:

Bhavadip B. Tanna

Student, Final Year B.Pharm, Maliba Pharmacy College, Tarsadi, Surat – 394 350, Gujarat, India

Nilesh K. Patel

M.Pharm.,Lecturer, Department of Quality Assurance, Maliba Pharmacy College, Tarsadi, Surat-394350, Gujarat, India
e-mail : nkpatel99@gmail.com

Mr. Bhavin P. Marolia

M.Pharm, Lecturer, Department of Quality Assurance, Maliba Pharmacy College, Tarsadi, Surat-394350, Gujarat, India
e-mail : bhavinrx001@gmail.com

Dr. Dinesh R. Shah

M.Pharm., Ph. D., Professor, Department of Quality Assurance, Maliba Pharmacy College, Tarsadi, Surat-394350, Gujarat, India