Valacyclovir free base

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MedKoo CAT#: 326809

CAS#: 124832-26-4 (free base)

Description: Valacyclovir, also known as valacyclovir, is an antiviral drug used in the management of herpes simplex, herpes zoster (shingles), and herpes B. It is a prodrug, being converted in vivo to aciclovir. Valaciclovir has been available as a generic drug in the U.S. since November 25, 2009. Valaciclovir is a prodrug, an esterified version of aciclovir that has greater oral bioavailability (about 55%) than aciclovir (10–20%). It is converted by esterases to the active drug aciclovir, as well as the amino acid valine, via hepatic first-pass metabolism. Aciclovir is selectively converted into a monophosphate form by viral thymidine kinase, which is far more effective (3000 times) in phosphorylation of aciclovir than cellular thymidine kinase.

Price and Availability

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Pricing updated 2020-05-28. Prices are subject to change without notice.

Valacyclovir free base is not in stock, may be available through custom synthesis. For cost-effective reason, minimum 1 gram order is requested. The product will be characterized by NMR, HPLC and MS analysis. Purity (HPLC) is usually >98%. CoA, QC data, MSDS will be provided when product is successfully made. The estimated lead time is 2-3 months. Please send email to to inquire quote.

Chemical Structure


Theoretical Analysis

MedKoo Cat#: 326809
Name: Valacyclovir free base
CAS#: 124832-26-4 (free base)
Chemical Formula: C13H20N6O4
Exact Mass: 324.1546
Molecular Weight: 324.341
Elemental Analysis: C, 48.14; H, 6.22; N, 25.91; O, 19.73

Related CAS #: 124832-26-4 (free base)   124832-27-5 (HCl)    

Synonym: Valacyclovir; valacyclovir. Val-ACV; Valtrex; Zelitrex

IUPAC/Chemical Name: 2-((2-amino-6-oxo-1,6-dihydro-9H-purin-9-yl)methoxy)ethyl L-valinate


InChi Code: InChI=1S/C13H20N6O4/c1-7(2)8(14)12(21)23-4-3-22-6-19-5-16-9-10(19)17-13(15)18-11(9)20/h5,7-8H,3-4,6,14H2,1-2H3,(H3,15,17,18,20)/t8-/m0/s1


Technical Data

Light yellow to yellow solid powder

>98% (or refer to the Certificate of Analysis)

Certificate of Analysis:

Safety Data Sheet (SDS):

Shipping Condition:
Shipped under ambient temperature as non-hazardous chemical. This product is stable enough for a few weeks during ordinary shipping and time spent in Customs.

Storage Condition:
Dry, dark and at 0 - 4 C for short term (days to weeks) or -20 C for long term (months to years).

Soluble in DMSO

Shelf Life:
>2 years if stored properly

Drug Formulation:
This drug may be formulated in DMSO

Stock Solution Storage:
0 - 4 C for short term (days to weeks), or -20 C for long term (months).

HS Tariff Code:


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12: Lee HJ, Kim JM, Kim GW, Mun JH, Song M, Kim HS, Kim BS, Kim MB, Ko HC. Fixed drug eruption due to acyclovir, valacyclovir and famciclovir. J Eur Acad Dermatol Venereol. 2015 Sep 15. doi: 10.1111/jdv.13261. [Epub ahead of print] PubMed PMID: 26369523.

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14: Ong SY, Truong HT, Diong CP, Linn YC, Ho AY, Goh YT, Hwang WY. Use of Valacyclovir for the treatment of cytomegalovirus antigenemia after hematopoietic stem cell transplantation. BMC Hematol. 2015 Jun 19;15:8. doi: 10.1186/s12878-015-0028-2. eCollection 2015. PubMed PMID: 26090121; PubMed Central PMCID: PMC4471913.

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16: Gnann JW Jr, Sköldenberg B, Hart J, Aurelius E, Schliamser S, Studahl M, Eriksson BM, Hanley D, Aoki F, Jackson AC, Griffiths P, Miedzinski L, Hanfelt-Goade D, Hinthorn D, Ahlm C, Aksamit A, Cruz-Flores S, Dale I, Cloud G, Jester P, Whitley RJ; National Institute of Allergy and Infectious Diseases Collaborative Antiviral Study Group. Herpes Simplex Encephalitis: Lack of Clinical Benefit of Long-term Valacyclovir Therapy. Clin Infect Dis. 2015 Sep 1;61(5):683-91. doi: 10.1093/cid/civ369. Epub 2015 May 8. Erratum in: Clin Infect Dis. 2016 Feb 15;62(4):530. Dosage error in article text. PubMed PMID: 25956891; PubMed Central PMCID: PMC4542890.

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20: Upadhyay P, Nayak K, Patel K, Patel J, Shah S, Deshpande J. Formulation development, optimization, and evaluation of sustained release tablet of valacyclovir hydrochloride by combined approach of floating and swelling for better gastric retention. Drug Deliv Transl Res. 2014 Dec;4(5-6):452-64. doi: 10.1007/s13346-014-0207-x. PubMed PMID: 25787207.