Table 4 Confidence interval of the titration value based on the nitrogen content, according to examples of uncertainty of measurements of each individual assay––Mat-CHN recalculations
From: Mat-CHN software for drug substance titrations in discovery and development
Experimental determination | Value (%w/w) | Uncertainty of measurement (examples) | Lower value (%w/w) | Higher value (%w/w) | Lower mole number recalculated | Higher mole number recalculated |
|---|---|---|---|---|---|---|
Water | 0.80 | 5% (relative) | 0.76 | 0.84 | 0.2540 | 0.2820 |
Water | 0.85 | 5% (relative) | 0.81 | 0.89 | ||
Butanol-1 | 0.35 | 5% (relative) | 0.3325 | 0.3675 | 0.0262 | 0.0292 |
Des-Chlorinated impurity | 0.3 | 30% (relative) | 0.21 | 0.39 | 0.0024 | 0.0046 |
Di-chlorinated impurity | 0.6 | 20% (relative) | 0.48 | 0.72 | 0,0049 | 0.0074 |
Chloride | 6.21 | 2% (relative) | 6.09 | 6.33 | 0.3338 | 0.3500 |
Chloride | 5.82 | 2% (relative) | 5.70 | 5.94 | 0.3124 | 0.3283 |
Chloride | 6.03 | 2% (relative) | 5.91 | 6.15 | 0.3239 | 0.3399 |
%N recalculated | 19.327 (e) | \( \frac{\left|r1-e\right|+\left|r2-e\right|}{2} \)= ± 0.038% (relative) | 19.365** (r1) | 19.289*** (r2) | ||
Titration* based on Nitrogen content | 91.72 | 0.038% (relative) | 91.68 | 91.75 | ||