SOP on Calculation of Yields

SOP on Calculation of Yields

1.0 Purpose: This SOP describes the guidelines for calculating yields at various stages during manufacture of a batch of drug product.

2.0 Scope: This SOP applies to Production staff.

3.0 Responsibility: Production Chemist to ensure that procedure is followed.

4.0 Materials and Equipment: As required.

5.0 Procedure: 

5.1 Actual yields and percentages of theoretical yield shall be determined after each appropriate phase of manufacturing, processing, packing, or holding of drug product. Such calculations shall be performed by one person and independently verified by a second person.

5.2 Theoretical yield is the maximum quantity that could be produced, based on quantities of components used, in the absence of any loss or error in the production.

5.3 Theoretical yield consists of the summation of weights of all raw materials entering the production cycle. For granulations, powders, and tablet coatings, an amount equal to the evaporated solvent should be subtracted.

5.4 Based on historical data an acceptable range for actual yield at each appropriate stage can be calculated.

5.5 The range is set so that 95% of batches produced will fall within the range when the process is operating correctly.

5.6 The purpose of this is to alert management to atypical situations that may require investigation.

5.7 Low yields may not only signal potential problems but may also indicate opportunities for process improvement with subsequent cost benefits.

5.8 Process loss can occur for a variety of reasons including dust extractions, spillage of components or product, machine losses such as in compression, machine adjustments, samples, or residue on equipment.

5.9 A second person verifies independently yield calculations.