Acyclovir Patent Expiration

Acyclovir is Used for treating cold sores caused by the herpes simplex virus. It was first introduced by Bausch Health Us Llc in its drug Zovirax on Mar 29, 1982. Other drugs containing Acyclovir are Avaclyr, Sitavig. 52 different companies have introduced drugs containing Acyclovir.


Acyclovir Patents

Given below is the list of patents protecting Acyclovir, along with the drug name that holds that patent and the company name owning that drug.

Drug Used in Drug Patent Number Drug Patent Title Drug Patent Expiry Drug Owner
Sitavig US8592434 Mucoadhesive buccal tablets for the treatment of orofacial herpes Jun 16, 2030 Ligand Pharms
Sitavig US8747896 Mucosal bioadhesive slow release carrier for delivering active principles Jun 03, 2027 Ligand Pharms
Sitavig US8791127 Mucosal bioadhesive slow release carrier for delivering active principles Mar 23, 2027 Ligand Pharms



A patent's expiry date may change depending upon legal activities going on that patent. Critical activities like abandoning of a patent, term extension of a patent or amendment of its claims can increase or decrease the life of a patent hence affecting its expiry date and in turn affecting the generic launch date of that drug. Tracking these ongoing activities on a patent application helps to keep an eye on the latest developments in the patent process of the drug which can give an idea of how early a drug's generic could be available. The next section provides a list of recent legal activities on Acyclovir's patents.

Given below is the list recent legal activities going on the following patents of Acyclovir.

Activity Date Patent Number
Patent litigations
Payment of Maintenance Fee, 8th Year, Large Entity 16 Dec, 2021 US8791127
Payment of Maintenance Fee, 8th Year, Large Entity 17 Nov, 2021 US8747896
Payment of Maintenance Fee, 8th Year, Large Entity 22 Apr, 2021 US8592434
Mail O.P. Petition Decision 22 Sep, 2020 US8791127
Mail O.P. Petition Decision 22 Sep, 2020 US8747896
Email Notification 22 Sep, 2020 US8747896
Email Notification 22 Sep, 2020 US8791127
Mail-Petition Decision - Granted 18 Sep, 2020 US8747896
Mail-Petition Decision - Granted 17 Sep, 2020 US8791127
Petition Decision - Granted 17 Sep, 2020 US8747896


Acyclovir's Family Patents

Family Patents

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Acyclovir Generic API Manufacturers

Several generic applications have been filed for Acyclovir. The first generic version for Acyclovir was by Roxane Laboratories Inc and was approved on Apr 22, 1997. And the latest generic version is by Cipla Ltd and was approved on May 2, 2025.

Given below is the list of companies who have filed for Acyclovir generic, along with the locations of their manufacturing plants worldwide.