Working standards are an integral part of any pharmaceutical laboratory. The working standard allows knowing the assay value of any tested product against the potency of the working standard. There are two types of standards in the laboratory (i) Reference Standard and (ii) Working Standard. Reference Standards are procured from Central Drug Laboratories like CDL Kolkata or any other Central Lab. Working standards are prepared in-house from tested Raw materials with proper repeat testing and after impurities analysis. Every laboratory follows some specific SOP of working standard adopted by them to ensure the authenticity of the working standard. Â
Preparation and handling of the working standard is a very crucial practice that requires a valid system in writing. The SOP for preparation and handling of the working standard is the document that directs and controls the working standard’s use in the QC department.
SOP on Preparation and handling of working standard
Objective:
This SOP describes the procedure for the preparation and handling of the working standard.
Scope:
This procedure is applicable to the Quality Control Department of XYZ Pharma company
Responsibility:
Quality control Officer/Executive.
Quality control Manager.
Accountability:
QA Head.
Procedure:-
5.1 Selection of batch
5.1.1 For the preparation of Working Standard, select an approved batch of respective material on the basis of its previous certificates of Analysis generated by the quality control department.
5.1.2 Generate the requisition to take the required material from the finished goods store as per the current version of the format.
5.1.3 Collect the sample as per the current version of finished goods sampling SOP. The quantity shall be taken as mentioned in the Working Standard specification.
5.2 Assigning batch numbers for working standards
Assign batch numbers for the working standard as per the following procedure.
Working standard No.: CGC/WS/XXX/01/YY-ZZ
Where:
WS = Working standard
CGC = Company name
XXX = Product Code
01 = Working standard number for a year.
YY-ZZ = Year for 2015-2016 (i.e 15-16)
5.3 Qualification of working standard against reference standard
5.3.1 The sample shall be qualified / standardized against the current lot of Reference Standard/Previous working standard and following common test shall be carried out for the preparation of the working standard.
- Description
- Identification
- Loss on drying / Water (by three different analysts)
- Related substances / Impurity (if applicable)
- Assay (by three different analysts)
5.3.2 Perform the assay and water (by KF / loss on drying wherever applicable) in triplicate by three different analysts and description and identification (if by FTIR ) once, by one analyst, as per Working Standard specification.
5.3.3 Take the average of triplicate analysis and results obtained from the individual analyst should not vary by more than 0.5%.
5.3.4 Relative standard deviation (% RSD) of three assay determinations should not more than 1.0%.
5.3.5 Relative standard deviation (% RSD) of three water / Loss on drying determinations should not more than 1.0 %.
5.3.6 The average of the results of three determinations of assay and LOD/Water shall be taken for routine analysis.
5.3.7 Upon completion of the qualification of the working standard and subsequent approval, prepare a certificate of analysis for the working standard and release for their intended use in the laboratory.
5.4 Packing of working standard.
5.4.1 Prepare the 13 vials of equal quantity of working standard in transparent/amber colour vials.
5.4.2 Number as follows, 1/13, to 13/13. 1/13 for first month from which working standard prepared.
5.4.3 Label the vials as per current version of format
5.4.4 Record the details of the working standard as the current version of format no.
5.5 Validity of the Working standard:
5.5.1The Validity of secondary reference standard shall be one year from the date of preparation or shelf life of the Salt whichever less is.
5.5.2 The validity of the vial shall be one month from the date of opening.
5.5.3 The validity of the vial 1/1 (Working standard reserve) shall be one year from the date of preparation.
5.6 Handling and reconciliation of working standard.
5.6.1 Store the vials in a desiccator and keep the same in a refrigerator at temperature 2-80C over silica gel (unless otherwise recommended for a new product).
5.6.2 The working standards are kept in lock and key and the key is available to QC Executive or QC Manager.
5.6.3 For routine uses, take one vial of working standard which is Stored in a desiccator containing silica gel. Seal the vial after every use with the Para-film.
5.6.4 At the time of opening of the vial, the date of opening shall be mentioned on the vial.
5.6.5 Place the vial at ambient temperature for 30 minutes prior to use.
5.6.6 After weighing of Working Standard vial shall be kept in a desiccator containing silica gel and record the usage of Working Standard on the current version of the format.
5.6.7 In case the working standard is consumed within the usage period and if required, transfer the working standard from the reserve pack and enter the repacking details in the register.
5.7 Working standard to customer or other users.
5.7.1 After receiving and verification the requisition for the working standard from the marketing department or from customers, draw the required quantity of the working standard reserve and pack as per the customer requirement.
Precaution; Vials should be tightly closed after each use and to be kept in an upright position. Working Standard must be replaced with a new one before/on the due date. The Working Standard bottle must be replaced with a new bottle within one month from the date of opening. Allow all such working standard standards, which are stored in the refrigerator (2°C to 8°C) to equilibrate to room temperature before using it. The initial color of the silica gel is dark blue. Replace the silica gel from the desiccators and plastic container of analytical standards when the color of silica gel fades from dark blue to light blue and all such replacement of silica gel is recorded in the current version of the format (Silica gel activation record).
5.8.6 Where any analytical standard is required to be dried before use, then use a clean and dried weighing bottle and not the original container as a drying vessel.
All the working standards are stored under lock and key, when not in use.
5.9 General Conditions
5.9.1 Running working standard must have the date of opening.
5.9.2 Use working standard within specified periods only.
5.9.3 If any abnormality is observed, immediately inform to QC Manager.
5.9.4 Reference Standard / Working Standard must be from the current lot and from official sources.
Only class ‘A’ grade glassware shall be used.
6.0 List of annexure and formats.
S. No.Format TitleAnnexure NumberFormat NumberNo. of Pages1.Silica gel activation and replacement record. 2.Sample request form 3.Specimen label 4.Working standard consumption and reconciliation record. table
7.0. References:
SOP on SOPs.
 Safety Precautions:
None.
 Abbreviations:
SOP – Standard operating procedure
% – Percent
ºC – Degree centigrade
QC – Quality control
No. – Number
KF – Karl Fischer
FTIR – Fourier Transform Infrared Spectrophotometer
RSD – Relative standard deviation
LOD – Loss on drying
ml – Milliliter
10.0 Recommended Distribution:
S. No Department Distribution [Yes / No]
01Quality Control Chemical section Yes
Revision History
SOP Number Effective Date Revision Date Changes done Change control number QC-07-R02
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