The purpose of this SOP is to lay down a procedure for rounding to significant figures without affecting the safety, identity, strength, purity and quality of the Product.
This SOP is applicable to Quality Control Department at manufacturing facility.
- Analyst or his designee shall be responsible for follow the SOP.
- The Head of Quality Control Department or his designee shall be responsible and implementation of the SOP.
- Rounding of numbers shall be done in the following cases:
- Analytical results observed in the laboratory (or calculated from experimental measurements) shall be compared with stated limits to determine whether there is conformance with compendial assay or test requirements. The observed or calculated values usually contain more significant figures than there are in the stated limit, and an observed or calculated result shall be rounded off to the number of places that is in agreement with the limit expression by the following procedure.
- Only one digit in the decimal place to the right of the last place in the limit expression shall be taken into account.
- If the digit is smaller than 5, it shall be eliminated and the preceding digit shall remain unchanged.
- If the digit is equal or greater than 5, it shall be eliminated and the preceding digit shall be increased by one.
- Illustration of rounding numerical values for comparison with requirements:
|Compendial Requirement||Un-rounded Value||Rounded Value||Complies|
|Assay Limit ≥ 98.0 %||97.96 %||98.0 %||Yes|
|97.92 %||97.9 %||No|
|97.95 %||98.0 %||Yes|
|Assay Limit ≤ 101.5 %||101.55 %||101.6 %||No|
|101.46 %||101.5 %||Yes|
|101.45 %||101.5 %||Yes|
|Limit Test ≤ 0.02 %||0.025 %||0.03 %||No|
|0.015 %||0.02 %||Yes|
|0.027 %||0.03 %||No|
|Limit Test ≤ 3 ppm||0.00035 %||0.0004 %||No|
|0.00025 %||0.0003 %||Yes|
|0.00028 %||0.0003 %||Yes|
- During calculation, the exact values shall be used. The final calculated value shall be rounded off. Both the original value and the rounded value shall be recorded side by side.
- Rounding of numbers shall not be done in the following cases :
- Disintegration time shall be recorded in minutes and seconds only.
- Dissolution time shall be recorded in minutes only.
- The pH values shall be recorded as displayed on the pH meter.
- Limits, which are fixed numbers, shall not be rounded off.
- While calibrating the weighing balance with standard weights, the weight displayed to the last decimal by the balance shall be recorded without rounding off.
- While weighing the test sample and/or a working standard, actual weight to the last decimal as displayed by the balance shall be recorded without rounding
- Volumetric solution strength should be rounded off with maintaining 4 decimals places e.g.: Original Value Rounded Value
0.001468 N 0.0015 N
Trainer : Head – Quality Control
Trainees : Quality Control chemist / Sectional Heads
Controlled Copy No. 1: Head of Department – Quality Assurance
Controlled Copy No. 2: Head of Department – Quality Control
Original Copy : Head – Quality Assurance
- REVISION HISTORY:
|Sr. No.||Revision No.||Change Control Number||Details of Revision||Reasons(s) for Revision|
|1||00||—-||New SOP||New SOP|