handling of reference standard and preparation of working standard

1.0 OBJECTIVE
1.1 To describe a procedure for handling of reference standard and Preparation of Working standard.
2.0 SCOPE
2.1 This procedure applies for handling of reference standard and Preparation of Working standard to the Quality Control Department
3.0 RESPONSIBILITY
3.1 Officer /Executive – QC
4.0 ACCOUNTABILITY

4.1 Head – QC
5.0 PROCEDURE

5.1 Procedure reference standards from sources as mentioned in Format for preparation and standardization of the WS and enter

the details in register as mentioned in Format
5.2 Store the reference standards in their original Stoppard containers away from heat and protected from light. If any special

storage conditions are specified for a particular reference standard, the same shall be followed.
5.3 Select currently approved raw material and collect the required amount of sample for qualified, working standard qualify against reference standard.
5.4 Procure reference standard from as per own suitable resource. Record the same in Format Prepare the working standard using

reference standard Record the same in Format
5.5 After the preparation of the WS, allotment a unique number as below. E.g. AA/XX/YY/ZZZ.
Where AA Stands for Department, XX Stands Working Standard, YY Stands for year and ZZZ stands for serial number.
For Example QC/WS/18/001.
5.6 The WS shall never be used after the validity. If any change in description is observed during storage the same shall be discarded.
5.7 A thorough investigation shall be made to find out the reason for such change and documented.
5.8 Refrigerated stored vials are to be brought to room temperature before use.
5.9 For Pharmacopoeia API’s :
5.9.1 The material to be used for the standardization of working standard must comply with Pharmacopoeia specifications.

5.9.2 The following tests shall be performed for standardizing working standards.
5.9.3 Description: Note down description of the material and physical appearance.
5.9.4 Identification: Wherever applicable, compare the IR spectrum of the sample under test with that of the Pharmacopoeia

reference standard. If IR is not applicable, test such as melting point or UV absorption maxima or Retention time in chromatogram

of test sample can be used for comparison with the reference standard.
5.9.5 Note: Use relevant Pharmacopoeia standard (IPRS / USPRS / BPCRS / EPCRS) of current lot.

5.9.6 Loss On Drying / Water Content by KF: Determine loss on drying by hot air/vacum oven or water content by

KF as mentioned in the individual standard testing procedure in Triplicate.
5.9.7 Acceptance criteria for Loss On Drying or water content: Each individual test result shall comply with the specification limit.
5.9.8 The overall RSD of six test result shall comply to the following requirements

Specification Limit	% RSD
Below 1.0 %	50.0
Between 1.1 % and 5.0 %	25.0
Above 5.0 %	10.0

5.9.9 Related Substances: Perform Related Substances as mentioned in the individual standard testing procedure

Pharmacopeia / in – house use relevant Pharmacopoeia reference standard (IPRS / USPRS / BPCRS / EPCRS) of current lot for standard preparation.
Acceptance criteria for Related Substances: Each Related Substances shall be complying within limit as per respective specification.
5.9.10 Assay: Perform assay in Triplicate as mentioned in the individual standard testing procedure.
In case of assay by HPLC / UV, use relevant Pharmacopoeia reference standard (IPRS / USPRS / BPCRS / EPCRS) of current lot

for standard preparation. For standardization HPLC method shall be given preference.
5.9.11 Acceptance criteria for assay: Calculate assay on dried basis or anhydrous basis.
Each individual assay result shall comply with the specification limit. The overall RSD of six assay values shall comply to the following requirements.

B (%)	% RSD
£ 2.0	NMT 1.0
From 2.1 to 2.5	NMT 1.25
From 2.6 to 3.0	NMT 1.5

B = Upper limit given in the definition of the individual monograph minus 100%, assuming that the upper limit

is set according to the reproducibility of the method.
5.9.12 Purity of working standards: Calculate % purity (i.e., assay on as is basis) of the working standard using the following formula:

% Purity = A (100-B)/100

Where,
A = Average assay of four test results calculated on dried basis or anhydrous basis.
B= Average LOD or water content by KF of four determinations.
5.9.13 Wherever the calculated % purity (i.e. Assay on as is basis) of the working standard exceeds 100%, the same shall be reported as 100% only.
5.9.14 Record the analysis details in data sheet.
5.10 Standardization of new lot: Standardization of new lot of working standards should be always against Pharmacopoeia reference standards of current lot.
5.11 For Non- Pharmacopoeia API:
5.11.1 For non-Pharmacopoeia materials (API) working / primary standards shall be procured along with certificate of analysis

from API manufacturer and used as test standard to qualify the WS against them.
5.11.2 Alternatively working standard of required quantity shall also be procured from the API manufacturer for routine use.
5.11.3 Standardization of new lot: New lot of working standard shall be standardized against the working / primary standard

procured from the manufacturer or the required quantity of working standard shall be taken from the manufacturer for routine use.
5.12 Selection of API’s for Working Standards:
5.12.1 i) API’s of Raw material shall be use for working standard qualification of current/latest manufacturing date.
ii) API’s of Raw material shall be use for working standard qualification of highly purity.
iii) API’s of Raw material shall be use for working standard qualification of approved vendor.
5.13 Assignment of expiry period for working standards:
5.13.1 i) Highly stable API’s shall be given a validity period of two year (Non-hygroscopic and having an expiry period of three years or above).
ii) Antibiotics or Hygroscopic API’s shall be given a validity period of one year (having an expiry period of two to four years).
iii) Vitamins or highly unstable API’s shall be given a validity period of six month ( having an expiry period of two to four years)
5.13.2 Before assigning expiry period for working standard QC personnel shall fill the assessment form (QCA/016/F02/R-00) along with

available supporting data and submit the same to QC In-charge.
5.13.3 The QC In-charge shall review the data and shall approve the proposed expiry period.
5.14 Storage of working standards: Working standards shall be stored in amber glass vial, place these vials in desiccator containing

self indicating Silica gel and keep the desiccator below 25ºC.
5.14.1 Working standard Certificate: Prepare working standard certificate as mentioned in format
5.15.1 Usage of working standards:
5.15.2 Distribute as per required quantity of working standard from the standardized quantity into 12/12/06 respectively in amber

glass vials and one/one vial for breakage and stock. Label affix of the working standard vials as per format
5.15.3 Note: The working standard shall be labeled for drying or moisture determination in accordance to the Pharmacopeia

standard or as recommended by the API manufacturer, wherever applicable based on the lab data generated.
5.15.4 The working standard vials should be used within 2 Month for two year validity and within 1 Month for one

year / six month validity respectively from the date of opening.
5.15.5 Note: If the API is highly hygroscopic single time usage is preferred. In such cases the vials shall be

filled with about 100 mg of working standard and label such vials as “for single use only”.
5.15.6 Enter the inventory details of each working standard uses in relevant format
5.15.7 Handling of working standard :
5.15.8 At the time of use, analyst is to ensure that the standard has not crossed the validity date. The analyst will keep

the standard out of the storage for a shorter period possible to prevent light and moisture from affecting the standard. When the

standards are stored in cool place, equilibrate to room temperature before use.
5.15.9 Do not transfer back into the vial, any excess portion of working standard used during weighing.
5.15.10 After the usage by the analyst the standards it is to be returned to the appropriate storage location immediately.
5.15.11 *NOTE: Working standards received with certificate of Analysis from Raw Material Manufacturer or from any other location can be used.
5.15.12 When self-indicating silica gel colour turns blue to red, dry the silica at 105°C till it regains its original colour. If it does not

regain its original colour change the silica.
5.15.13 All WS should be listed as mentioned in Format
5.15.14 In case we shall be qualify working standard from PTL (NABL Approved Lab), Perform as per site approved

respective sop’s and related document should be comply.
5.15.15 Destruction of the working standards
5.15.16 Deface the vial label.
5.15.17 Transfer the content of the vial in a container.
5.15.18 Rinse the vial with water and send it for disposal.
6.0 RELATED DOCUMENT
6.1 Nil

7.0 REFERENCE
7.1 In House
8.0 FORMATS
8.1 List of Reference Standard
8.2 Working Standard Assessment Form
8.3 Working Standard Certificate / Report
8.4 Working Standard Analytical Data Sheet
8.5 Label for Working Standard
8.6 List of Working Standard
8.7 Working Standard Consumption Record
8.8 Reference Standard Receipt, Issuance and Consumption Record
8.9 Working Standard Destruction Record
9.0 ABBREVIATIONS
9.1 No. : Number
9.2 QA : Quality Assurance
9.3 QC : Quality Control
9.4 QCA : Quality Control Analytical
9.5 SOP : Standard Operating Procedure
9.6 RSD : Relative Standard Deviation
9.7 LOD : Loss on drying
9.8 Ref. No : Reference Number
9.9 % : Percentage
9.10 °C : Degree Celsius
9.11 A. C. : Air conditioned
9.12 COA : Certificate of Analysis
9.13 WS : Working Standard
9.14 Dept. : Department
9.15 PTL : Public Testing Laboratory