Pharmacopeial Specifications
| Test | PhEur | USP-NF | JP |
|---|---|---|---|
| Identification | ✓ | ✓ | ✓ |
| Appearance | ✓ | — | ✓ |
| pH (5% w/v solution) | 2.2–2.5 | 1.8–2.4 | 1.8–2.5 |
| Water Content | 7.5–9.0% (Monohydrate) | ≤0.5% (Anhydrous) | ≤0.5% (Anhydrous) |
| Heavy Metals | ≤10 ppm | ≤10 ppm | ≤10 ppm |
| Assay | 99.5–100.5% | 99.5–100.5% | 99.5–100.5% |
Applications in Pharmaceutical Formulation or Technology
Citric acid is widely used in pharmaceutical formulations as an acidifying and buffering agent in oral, topical, and parenteral preparations. It enhances solubility and stability of active ingredients, acts as a chelating agent in metal-sensitive formulations, and improves palatability in syrups and effervescent tablets. Additionally, it is used in combination with bicarbonates for effervescent drug delivery systems.
Comments
Citric acid is naturally occurring and widely used in pharmaceutical, food, and cosmetic applications. The monohydrate form is more commonly used in aqueous formulations, while the anhydrous form is preferred for effervescent and dry formulations due to its low moisture content. It is generally recognized as safe (GRAS) and approved for use in multiple regulatory jurisdictions.
