Table 1 Acceptance criteria for chitosan and chitosan hydrochloride according to the European and US Pharmacopoeias [26, 27]
Parameter | Eur. Ph. 6.0 Chitosan·HCl | USP Ph. 34-NF 29 Chitosan |
|---|---|---|
Appearance | White solid | – |
Degree of deacetylation | 70.0%–95.0% | 70.0%–95.0% |
Distribution of molecular weighta | – | 0.85–1.15 |
pH of 1% (g/mL) solution | 4.0–6.0 | – |
Loss on dryinga | – | < 5% |
Total Impurities/Insolubles | ≤ 0.5% | ≤ 1.0% |
Heavy metals | ≤ 40 ppm | ≤ 10 ppm |
Iron | – | ≤ 10 ppm |
Sulfated asha | ≤ 1.0% | – |
Protein | – | ≤ 0.2% |