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 G 150 mg U 786 ADVIL PM OP 700 E 2 XR 200 P 4 M525 Shire L126 NL 571 CTI 116 2 BR 522 VP 076 logo and FHPC 400 704 CB7 A CS SZ 214 DEPAKENE 54 036 Black B 749 617 5 220 AA 76 MP 201 3126 IP 193 SZ 395 TriStart C148 M2A3 57344 CM3 T127 1034 54 518 12.5 L751 EC-NAPROSYN