Impurities are undesirable chemical components that remain in the active pharmaceutical ingredient during formulation. Impurities may reduce a product's efficacy.

CAS Number
341-69-5
Alternate CAS Number
341-69-5 (Citrate) , 83-98-7 (Free Base)
CAS Number
127-33-3
Alternate CAS Number
64-73-3(HCl Salt)
CAS Number
564-25-0
Alternate CAS Number
10592-13-9(HCl salt);17086-28-1(Doxycycline Monohydrate)
CAS Number
120014-06-4
Alternate CAS Number
120011-70-3(HCl Salt)
CAS Number
23828-92-4
Alternate CAS Number
18683-91-5(Freebase)
CAS Number
107814-37-9
Alternate CAS Number
1384955-66-1(HCl Salt)
CAS Number
2088879-81-4
Alternate CAS Number
2356152-56-0(HCl Salt)
CAS Number
101900-43-0
Alternate CAS Number
101900-44-1(HCl salt)