Preparation And Handling Of Working Standards


To establish procedure for preparation and handling of working standards.

2.0  SCOPE:

This procedure is applicable for all working standards which are to be used as reference standard for analysis.


3.1  Doing: Technical Assistant.

3.2  Checking: Executive/Manager.


Head of the Q.A Department.


5.1  Select latest approved batch of Raw Material preferably having maximum purity and minimum impurity level.

5.2  Collect the required quantity of material from the selected batch.

5.3  Give the reference number to working standard as follows.



                       X= corresponds the first alphabet of name of raw material.

000= corresponds to Sr. No. starting from 001 continuously to have details of total working standard in quality control laboratory.

A= corresponds the last digit of year in which working standard prepared.

BB= corresponds the no. of vial prepared for particular working standard starting from 01.

5.4  For the second reference standard of same material to be prepared in the same current year then the suffix of alphabet A, B, C…… is to be added in the above logic with A. i.e. X000/AS/BB


AS= last digit of year with suffix.

5.5  Carry out the following test for preparation of working standard.

5.5.1        Assay (in six sets by two or more than two different chemists).

5.5.2        Loss on drying/ water content (in two sets by two different chemists).

5.5.3        Chromatographic purity/ related substance.

5.5.4        I.R. (where applicable).

5.6  Carry out assay determination against reference standard wherever possible.

5.7  Enter the results in the protocol of the respective material prepared as per SOP and also attach the Xerox copy of original C.O.A.

5.8  Calculate the average of six assay values obtained on as is basis. The RSD of these six values should not be more than 1.0% for chemical assay and 5.0% for microbial assay.

5.9  Store the material in light resistant glass vials closed with rubber bungs and sealed with aluminum seal.

5.10                            Label the vials with the following details.

5.10.1    Name of working standard.

5.10.2    Ref. No.

5.10.3    Assay (as such).

5.10.4    LOD/ water content.

5.10.5    Date of preparation.

5.10.6    Use before.

5.11                            Assign one year shelf life for working standard except following working standard for which assign shelf life six months.

5.11.1    Ranitidine HCl.

5.11.2    Nifedipine.

5.11.3    Omeprazole.

5.11.4    Nicorandil.

5.11.5    Captopril.

5.12    Store all additional vials of working standard in A.C control area (below 27oC)/ refrigerator (between 2 to 8oC).

5.13    Keep one vial of each working standard in the allocated area in a plastic bottle containing silica bag.

5.14    Every month change the previous vial with fresh vial along with silica bag for all working standard, by referring respective bin card.

5.15    Check the % assay and LOD of each working standard on its expiry date as per initial test method applied and record results.

5.16    If the difference is more than 1%, between initial assay and assay on expiry inform the department head.

5.17    In case on expiry if new material is not available then extend the shelf life for that working standard as per point no. : 5.10 or till new material received on the basis of the result obtain on retest.

5.18    Maintain the issue record.

5.19    Destroy the expired vials of working standard after completion of shelf life and keep the record.

5.20    Procedure for discard:

5.20.1    Empty the contents in waste beaker containing water. After the material gets soften, decant the water & transfer the paste into the polyethylene bag. This paste is then sent to scrap.

5.20.2    Deface the labels of the working standard vial or ampoules.

5.20.3    Discard the vial & ampoule into the dust bin for broken glassware.


Revision No.

Effective Date







7.1  Not Applicable.


8.1  Not Applicable.



Expanded Form


Standard operating procedure