Table 3.

Summary of impurity testing results for nonproprietary fingolimod variants

Test	Reference	Out-of-specification range	Out-of-specification magnitude	Proportion of total drugs found to be out-of-specification (%)
Sulfated ash	Proprietary	0.13%–0.91%	Up to 8-fold larger	73
Heavy metals	Proprietary	26–32 ppm	Up to 3-fold larger	100
Unspecified impurities	ICH guidelines	0.18%–2.18%	Up to 20-fold larger	46

Abbreviations: ICH, International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use; ppm, parts per million.