Pioglitazone EP Impurity C; Pioglitazone USP Related Compound C; N-Alkyl Pioglitazone;5-[[4-[2-(5-Ethyl-2-pyridinyl)ethoxy]phenyl]methyl]-3-[2-(5-ethyl-2-pyridinyl)ethyl]-2,4-thiazolidinedione;N-Alkylpioglitazone,(ยฑ)-5-{4-[2-(5-Ethylpyridin-2-yl)ethoxy]benzyl}-3-[2-(5-ethylpyridin-2-yl)ethyl]thiazolidine-2,4-dione,5-[[4-[2-(5-Ethyl-2-pyridinyl)ethoxy] phenyl]methyl]-N-[2-(5-ethylpyridin-2-yl)ethyl]-2,4-thiazolidinedione,Pioglitazone Impurity