A guarana extract reported as 20% caffeine on a dry basis does not necessarily supply 50 mg of caffeine in 250 mg of powder weighed from the bag. If that powder contains 5% water and the assay excludes water from its denominator, the calculated contribution is 47.5 mg. Check the reporting basis before using a certificate of analysis (COA) to set a pouch formula.
GuaranaPouches.com editorial guide for formulation and purchasing teams. Calculations are hypothetical training examples, not batch results or consumer dosing advice.
What dry basis and as-is mean on a guarana extract COA
An as-is result expresses caffeine against the material in its tested condition. A dry-basis result expresses it against a mass corrected for the specified drying loss. The words beside the assay therefore matter as much as the percentage. “Caffeine: 20.0%” leaves an important question unanswered if the report never identifies that basis.
The Indian Pharmacopoeia Commission’s calculations guidance explains conversion between as-is and dried or anhydrous assay values. That is an analytical calculation reference, not a guarana pouch specification. Ask the ingredient laboratory which correction its method uses. Also confirm whether 20% is an actual batch result, a minimum specification or a rounded product description. A standardized extract specification should never be presented as the natural caffeine percentage of every guarana seed.
Five fields to request together
- Actual caffeine result, with units and reporting basis.
- Water or loss-on-drying result from the identified lot.
- Test method and the correction used in the assay calculation.
- Sample date, lot number and storage condition.
- Specification limits, separately from measured results.
Calculate the caffeine contribution from the powder you weigh
For an example in which the assay is corrected only for water, multiply the dry-basis caffeine fraction by the fraction of material remaining after water is excluded. The result is the caffeine fraction of the as-is powder. Use percentages consistently: 20% becomes 0.20, and 5% becomes 0.05.
As-is caffeine fraction = dry-basis fraction × (1 − water fraction)
Caffeine contribution = extract mass × as-is caffeine fraction
| Input or result | Value |
|---|---|
| Extract weighed | 250 mg |
| Caffeine, dry basis | 20.0% |
| Water used in this example | 5.0% |
| As-is caffeine | 20.0% × 0.95 = 19.0% |
| Calculated caffeine contribution | 250 mg × 0.19 = 47.5 mg |
A 50 mg formulation target would require approximately 263.2 mg of this example extract before considering other caffeine sources or manufacturing controls. If the COA already reports 20% as-is, applying the 5% correction again would be wrong. The arithmetic supports formula development; finished-pouch testing remains necessary.
Why loss on drying is not always a water result
A drying test can remove more than water. The public description of USP General Chapter 731, Loss on Drying, defines the measurement in terms of volatile matter removed under specified conditions. Treating every drying loss as water can therefore use the wrong denominator. A COA marked “anhydrous basis” also deserves a method-specific explanation rather than an automatic substitution of the loss-on-drying value.
For procurement, ask the laboratory to show the basis conversion on the same report or in a signed clarification. Keep that clarification with the approved ingredient specification. If two laboratories disagree, compare the reporting basis before concluding that the ingredient has lost caffeine. Then compare sample identity and preparation. Sending a supplier a screenshot of the percentage alone discards the information needed to investigate the difference.
Carry the corrected value into a controlled pouch formula
The formulator should record which assay value was used and why. Purchasing should not replace that value with a catalog specification when a new lot arrives. If the approved formulation permits lot-specific potency adjustment, the adjustment needs a documented calculation and an authorized formula version. A buyer should request this process without assuming that every supplier uses the same approach.
For the finished product, specify total caffeine per pouch and the test plan. Guarana extract may be the only caffeine source, or the formula may contain another source that must be included in the total. Our individual versus composite testing guide explains why a pooled result does not describe every pouch. Include the reporting basis in your private-label RFQ, alongside the declared strength and the agreed acceptance criteria.
Frequently asked questions
Does 20% guarana extract always contain 200 mg caffeine per gram?
It does when the applicable caffeine result is 20% by mass on an as-is basis. A dry-basis result requires the stated basis correction before it can describe a gram of powder as weighed.
Can I use the maximum moisture specification in the calculation?
A maximum limit is not the measured moisture of a particular lot. Ask for the actual result and the laboratory’s reporting convention before making a lot-specific potency calculation.
Does this calculation replace an HPLC test of finished pouches?
No. It estimates the ingredient contribution from stated inputs. It does not measure blending uniformity, fill variation or the caffeine recovered from a finished pouch.
References and further reading
- Indian Pharmacopoeia Commission: General Calculations in Indian Pharmacopoeia, version 1.1.
- USP: General Chapter 731, Loss on Drying, public chapter description.
- Guarana extract COA purchasing checklist.
- Finished-pouch HPLC testing.
References checked 29 October 2026. The worked example and supplier questions are editorial analysis. They do not establish a release specification for a commercial product.