Calculations and weighing

Procedure

1. Define the strength basis: w/w, w/v, v/v, salt or free base. Distinguish added volume from final q.s. ad.
2. Check composition and mass balance against the source. Do not silently repair discrepancies or assume water-like density.
3. Record the scaling factor and any assay, water or equivalence correction only with suitable data. A second person independently checks critical calculations.
4. Select a balance and vessel within the qualified range. A quantity below reliable weighing capability requires an approved alternative procedure.
5. Weigh one material at a time, verifying identity and lot. Record the actual quantity, unit, operator and independent check where required.
6. Reconcile inputs, losses and final yield against predefined limits. Do not simply top up volume to conceal active-substance loss.

Edition-specific detail

For scaling, k = requested final quantity / reference quantity; apply the same k to every quantitative ingredient. A q.s. ad instruction means make up to the final total, not add that entire amount. The reviewer recalculates from the original order, not merely the operator’s result. Document any justified salt, hydration or potency correction separately.

Related forms

F-002, F-003