we have the following Cefdinir impurities( for detailed information,please visit the website http://www.pipitech.com/cefdinir_53989.html ):

Cefdinir Impurity A (CP)
Cefdinir Impurity B (CP)
Cefdinir Impurity C(CP)（7-AVCA)）
Cefdinir Impurity D(CP)（Cefdinir Sulfoxide ）
Cefdinir Impurity E (CP)
Cefdinir Impurity F (CP)
Cefdinir Impurity G (CP)
Cefdinir Impurity H (CP)
Cefdinir Impurity IJKL 
Cefdinir Impurity M (CP)，Cefdinir Lactone
Cefdinir Impurity N (CP) 
Cefdinir Impurity O(CP)
Cefdinir Impurity  PQ(CP)
Cefdinir Impurity R，(E)-Cefdinir
Cefdinir Impurity S(CP)
Cefdinir Impurity TU(CP)
Cefdinir Impurity A (USP)
Cefdinir Impurity 11（Acetamide Cefdinir）
Cefdinir Dimer
7-AVCA-Dimer（Cefdinir Mother Nucleus Dimer ）
Cefdinir Degradation Impurity 1
Cefdinir Acetaldehyde Analogue(Cefdinir Glyoxalic Analogue)
Cefdinir Acetaldehyde Analogue Side-chain Acid
Cefdinir Double Mother Nucleus
Cefdinir Glycine Oxime Acid Aldehyde

etc.