Weight to Weigh After Assay and Water Correction
Weight of an active-ingredient lot to weigh for a target of pure active, after the assay and the water correction.
Open the tool → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Target amount of pure active
- 500
- Unit of the target
- mg
- Assay of the lot, percent
- 98.5
- Basis the assay is stated on
- Anhydrous basis
- Water content or loss on drying, percent
- 4.2
Result: Weigh 529.869 mg of this lot for 500 mg of pure active.
The tool opens with these values already filled in. Replace them with your own.
What you enter
- Target amount of pure active
- Unit of the target
- Assay of the lot, percent (certificate of analysis)
- Basis the assay is stated on: as is, anhydrous or dried
- Water content or loss on drying, percent (required for an anhydrous or dried assay)
- Salt factor: weight of salt per weight of base (optional)
How this is calculated
Citation
Arithmetic identity: weigh = target ÷ (assay ÷ 100) for an as-is assay, and ÷ (1 − water ÷ 100) as well for an anhydrous or dried assay. The assay, its basis and the water content are read from the lot's certificate of analysis.
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.