Pill Identification by Imprints: S 521 Home Pill Identification by Imprints: S 521 2 results CETIRIZINE HCL 10 MG TABLET Side 1: S 521 Color: White Side 2: Shape: Rectangular (Rounded End) CETIRIZINE HCL 10 MG TABLET Side 1: S 521 Color: White Side 2: Shape: Rectangular (Rounded End) Other Popular Drug Imprint KU 261 C 74 MINOXIDIL 10 2470 C020 CYP 161 FH 160 ML 71 APO 102 F 76 par 221 AZ 010 logo and LD 773 2775 A-293 M377 1386 Librax GSI500 3973 LILLY 3250 C4 or C2 GG 962 D 27 COB SC 1 ALDACTAZIDE 25 L657 SG 326 logo 222 GG 44 WPI 3660 CP 401 BY1 PH 063 VIRACEPT RDY 664 C181 RIFADIN 150