SOP-007 · Calculations and weighing

SOP-007 · 1.0 · 10.09.2026

Scope

Batch calculations, units, potency corrections and weighing records.

Roles and prerequisites

Responsible pharmacist: approves implementation and release. Trained operator: performs and records work. Reviewer: verifies critical items. Specialist clinician/analytical partner: as specified.

Before implementation complete local document IDs, named roles, suitable equipment, specific specifications and acceptance criteria. Check the applicable framework in your country.

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.

Stop criterion

Related records

• F-002 · Master formulation record
• F-003 · Blank batch record

Sources

• AEMPS PN/L/OF/001/00 — Pesada
• NAPRA — Guidance Document for Non-sterile Preparations

These sources inform the original editorial synthesis. Their publishers do not adopt or endorse this SOP.

Local approval

Local version: __________ Effective date: __________
Author: __________ Reviewer: __________ Pharmacist approval: __________
Signatures / dates: __________ Next review: __________