Reconstitution calculator (revision 12)
Old revision·21:50, 22 Oct 2024·SchemaSorcha
| Reconstitution calculator | |
|---|---|
| Inputs | Vial mass (mg), diluent volume (mL), dose (mg or µg), syringe scale |
| Outputs | Concentration, dose volume, syringe units, doses per vial |
| Reference tool infobox · conventions | |
The reconstitution calculator relates the four quantities involved in dissolving a lyophilised peptide and drawing a dose from it: the mass of solid in the vial, the volume of diluent added, the intended dose, and the reading on the syringe barrel. All four are connected by one division, and almost every error reported in the literature and in community accounts is a confusion between two of them rather than a failure of the arithmetic itself.[1]
The calculation is a routine unit conversion: concentration is mass divided by volume, dose volume is dose divided by concentration, and a syringe unit is one hundredth of a millilitre on the U-100 scale. The tool below performs those operations and shows each intermediate result, because the intermediate is where a mistake becomes visible.
This page is a reference tool and not a clinical decision aid. It converts numbers a reader enters; it does not select a dose, and it has no knowledge of the vial, the label claim, or the person. See Project:Medical disclaimer.
The calculator
[edit]Enter the label mass of the vial, the volume of diluent, and the intended dose. The tool reports the resulting concentration, the volume that dose occupies, the reading on the selected syringe scale, and how many doses the vial contains.
Worked examples
[edit]The tool's defaults correspond to the first row below. Each row is a division; none of them requires a calculator, and reproducing one by hand is a useful check that the inputs were entered as intended.
| Vial | Diluent | Concentration | Dose | Dose volume | U-100 units |
|---|---|---|---|---|---|
| 5 mg | 2.0 mL | 2.5 mg/mL | 0.25 mg | 0.10 mL | 10 |
| 5 mg | 2.0 mL | 2.5 mg/mL | 0.50 mg | 0.20 mL | 20 |
| 5 mg | 1.0 mL | 5.0 mg/mL | 0.25 mg | 0.05 mL | 5 |
| 10 mg | 2.0 mL | 5.0 mg/mL | 2.5 mg | 0.50 mL | 50 |
| 10 mg | 1.0 mL | 10 mg/mL | 1.0 mg | 0.10 mL | 10 |
| 15 mg | 3.0 mL | 5.0 mg/mL | 7.5 mg | 1.50 mL | 150 |
| 2 mg | 2.0 mL | 1.0 mg/mL | 100 µg | 0.10 mL | 10 |
References
- ^ United States Pharmacopeia, General Chapter <797>, "Pharmaceutical Compounding — Sterile Preparations". USP–NF, current revision.