Penciclovir Impurity A with CAS No: 100199-40-4 is an impurity standard of Penciclovir. Penciclovir, a guanine analogue, is a topical antiviral medication used for the treatment of herpes simplex virus (HSV) infections, including cold sores and genital herpes. Structurally related to acyclovir, it requires phosphorylation by viral thymidine kinase to its active form, penciclovir triphosphate, which competitively inhibits the incorporation of deoxyguanosine triphosphate into the growing viral DNA chain. This disruption in viral DNA synthesis limits the replication of the virus, reducing the severity and duration of herpes infections. Penciclovir is commonly formulated in creams or topical solutions, allowing for localized application and minimizing systemic absorption, thereby providing effective and targeted relief for affected individuals. Buy high quality Penciclovir Impurity A from Molsyns Research. Molsyns Research is one of the leading manufacturer and exporter of Penciclovir Impurity A