Sulfamethoxazole impurity A - N-(4-(5-methyl)-isoxazol-3-ylsulphamoyl)phenylacetamide

Sulfamethoxazole impurity F - 4-amino-N-(3-methylisoxazol-5-yl)benznesulphonamide

Naltrexone impurity C - N-(3-butenyl)-noroxymorphone

Ranitidine for system suitability

Stavudine

Famotidine impurity D -: 3-[[[2-[(diaminomethylene)amino]thiazol-4-yl]methyl]sulphanyl]propanamide

Iopamidol impurity H - 4-chloro-N,N'-bis(2-hydroxy-1-(hydroxymethyl)ethyl)-5- (2-hydroxypropanoyl)amino)2,6-diiodobenzenz-1,3-dicarboxamide

Methylrosanilinium chloride for system suitability

Oxeladin impurity C - 2-(diethylamino)ethyl 2-ethyl-2-phenylbutanoate

Salicylic acid impurity B - 4-hydroxyisophthalic acid