Ferrous Sulfate Syrup
DEFINITION
Ferrous Sulfate Syrup contains, in each 100 mL, NLT 3.75 g and NMT 4.25 g of ferrous sulfate heptahydrate (FeSO4·7H2O), equivalent to NLT 0.75 g and NMT 0.85 g of elemental iron.
Ferrous Sulfate Syrup is prepared as follows.
| Ferrous Sulfate | 40 g |
| Citric Acid, hydrous | 2.1 g |
| Peppermint Spirit | 2 mL |
| Sucrose | 825 g |
| Purified Water, a sufficient quantity to make | 1000 mL |
Dissolve the Ferrous Sulfate, Citric Acid, Peppermint Spirit, and 200 g of Sucrose in 450 mL of Purified Water, and filter the solution until clear. Dissolve the remainder of the Sucrose in the clear filtrate, and add Purified Water to make 1000 mL. Mix, and filter if necessary, through a pledget of cotton.
IDENTIFICATION
• A. Identification Tests—General, Iron, Ferrous Salts 
191
and Sulfate 191
191 and Sulfate 191 Sample solution: Dilute 1 mL of Syrup with water to 100 mL.
Acceptance criteria: Meets the requirements
ASSAY
• Procedure
Sample: 25 mL of Syrup
Blank: Proceed as in the Analysis without the Sample.
Titrimetric system
(See Titrimetry 541.)
541.)Mode: Direct titration
Titrant: 0.1 N ceric sulfate VS
Indicator: Orthophenanthroline TS
Endpoint detection: Visual
Analysis: Add 15 mL of 2 N sulfuric acid and 100 mL of water to the Sample, and shake well. Add 3 drops of orthophenanthroline TS, and titrate with Titrant until the color changes. Perform a blank determination.
Calculate the amount of ferrous sulfate heptahydrate (FeSO4·7H2O) in g per each 100 mL of Syrup:
Result = {[(VS 
VB) × N × F]/W} × 100
VB) × N × F]/W} × 100| VS | = | = Titrant volume consumed by the Sample (mL) |
| VB | = | = Titrant volume consumed by the Blank (mL) |
| N | = | = actual normality of the Titrant (mEq/mL) |
| F | = | = equivalency factor, 0.278 g/mEq |
| W | = | = volume of Ferrous Sulfate Syrup for the Sample taken (mL) |
Acceptance criteria: 3.75–4.25 g in each 100 mL
ADDITIONAL REQUIREMENTS
• Packaging and Storage: Preserve in tight containers.
• Labeling: Label the Syrup in terms of the content of ferrous sulfate (FeSO4·7H2O) and in terms of the content of elemental iron.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
| Topic/Question | Contact | Expert Committee |
|---|---|---|
| Monograph | Natalia Davydova Scientific Liaison 1-301-816-8328 | (DS2010) Monographs - Dietary Supplements |
USP35–NF30 Page 3181