Chodimella Sahitya Bharathi and Mukthinuthalapati Mathrusri Annapurna*
GITAM Institute of Pharmacy, GITAM (Deemed to be University), Visakhapatnam, India
*Corresponding Author: Mukthinuthalapati Mathrusri Annapurna, GITAM Institute of Pharmacy, GITAM (Deemed to be University), Visakhapatnam, India.
Received: April 07, 2021; Published: April 30, 2021
Valacyclovir is used for the treatment of viral infections caused by Herpes simplex viruses which include shingles, chickenpox and genital herpes. Valacyclovir converts rapidly into acyclovir after its oral administration and there by inhibits the viral DNA replication. In the present paper the authors have reviewed the analytical methods already published till now in the literature for the estimation of Valacyclovir in pharmaceutical formulations and in biological samples.
Keywords: Valacyclovir; Drug; DNA
Lines 16-22: Valacyclovir is an anti-viral drug. Valacyclovir is chemically defined as 2-amino-3-methyl butanoate derivative of acyclovir [1,2]. Valacyclovir (Figure 1) has a molecular formula C13H20N6O4 and molecular weight 360.8 g/mole and it is soluble in water. The pKa values of Valacyclovir are found to be 1.90, 9.43 and 7.47 respectively. Valacyclovir is converted into Acyclovir tri phosphate which competitively inhibits viral DNA synthesis by incorporating into the DNA polymerase of virus and finally inactivates and terminates the DNA polymerase chain [3,4].
Figure 1: Chemical structure of valacyclovir.
Valacyclovir is available as tablets with brand names VALTOVAL (Sun Pharmaceutical Industries Ltd., India) and VALCIVIR (Cipla Ltd, India) etc. with a labelled claim of 500 mg for each of the brand product. Valacyclovir is also available as tablets in combination with Cefotaxime, Ritonavir etc. in marketed formulations. This article summarises the analytical techniques proposed by different authors for the quantification of Valacyclovir. Such analytical techniques include spectrophotometry [5-9] (Table 1), liquid-mass spectrometry [LC-MS] [10], LC-MS/MS [11,12], ultraperformance liquid chromatography [UPLC] [13], high performance liquid chromatography [HPLC] [14-19]. Reverse phase high performance liquid chromatography [RP-HPLC] methods have been used to determine the drug following enantiometric separation [20], in biological fluids [21,22], impurity profiling using Box-Behnken design [23] and related substances [24-26]. Table 2 presents some of the significant chromatographic conditions and parameters.
Reagent |
Linearity (µg/ml) |
λmax (nm) |
Comment |
Reference |
0.1N HCl |
5-25 |
255 |
UV region |
[5] |
Vanillin PDAB |
20-100 100-500 |
428 388 |
Visible region UV region |
[6] |
Distilled water |
4-24
|
252
|
UV region |
[7] |
Phenyl hydrazine HCl/Fe3+/H+ Fe3+/1,10-phenanthroline |
2 - 10 5 - 25 |
520 |
Visible region |
[8] |
Sodium acetate (pH 4.0) Phosphate buffer (pH 5.0) Phosphate buffer (pH 7.0) Borate buffer (pH 9.0) 0.1N NaOH |
1 - 80 |
251 251 252 253 265 |
UV region |
[9] |
Table 1: Review of spectrophotometric methods.
Mobile phase (v/v) |
Column |
Linearity (µg/ml) |
Comment |
Ref |
Liquid chromatography- Mass spectrometry methods |
||||
Acetonitrile: 0.05% Aq. diethyl amine (50:50)
|
Porous graphitized carbon (PGC) |
0.02 - 0.80 |
LC-ESI/MS Ganciclovir (Internal standard) Human plasma |
[10] |
Mobile phase A: 2 mM Ammonium acetate: 0.2% Formic acid: Mobile phase B: Acetonitrile: 0.2% Formic acid |
Waters Atlantis T3 C18 |
- |
LC-MS/MS (Gradient mode) Mouse & human plasma |
[11] |
0.1% Formic acid: Methanol (30:70)
|
Gemini C18 |
- |
LC-ESI-MS/MS Human plasma and its metabolite (Isocratic mode) |
[12] |
Ultra performance Liquid chromatography |
||||
0.1% o-phosphoric acid: Acetonitrile (70: 30) |
- |
12.5 - 75 |
UPLC |
[13] |
High performance Liquid chromatography |
||||
Mobile phase A: Acetic acid: Water (1∶1000) Mobile phase B: Methanol (70∶ 30) |
ODS C18
|
- |
HPLC |
[14] |
0.1% Formic acid: Acetonitrile (90: 10) |
C18 (Develosil) |
10 - 50
|
HPLC
|
[15] |
Acetonitrile: Phosphate buffer (pH- 3.6) (50:50) |
Hypersil ODS C18 |
0.5 - 200 |
HPLC
|
[16] |
Acetonitrile: Phosphate buffer (pH- 3.6) (50:50) |
Hypersil, ODS C18 |
0.5 - 200 |
HPLC
|
[17] |
Mobile phase A: NaH2PO4 buffer (pH 3.5 adjusted with dilute ortho phosphoric acid) Mobile phase B: Acetonitrile: Methanol (60:40) |
Hypersil BDS C18
|
15 - 225
|
HPLC
|
[18] |
Acetonitrile: Phosphate buffer (pH- 3.6) (50:50) |
Hypersil ODS C-18 |
0.5 - 200
|
HPLC
|
[19] |
n-Hexane: Ethanol: Diethyl amine (30:70:0.1) |
Chiralpak AD |
0.9 - 6 |
Enantio selective |
[20] |
Acetonitrile: 0.025 M mono ammonium phosphate buffer (pH 4.0; adjusted with 10% diluted phosphoric acid) (2:98) 1-methylguanosine (Internal standard) |
Symmetry Shield RP-8 |
0.5 - 20 |
Biological fluids (Serum Dialysis liquid & Urine) Run time 12 min |
[21] |
Acetonitrile: Methanol: 0.067 M KH2PO4 (27:20:53) |
Waters Spherisorb C18 |
0.005 - 20
|
Human serum |
[22] |
Mobile phase A: Buffer (pH 3): Acetonitrile (95: 5) Mobile phase B: Acetonitrile: Methanol (90:10) Diluent: Buffer: Acetonitrile (50: 50) |
ODS 3V |
50 - 150 |
Box-Behnken design Impurity Profiling and Related Products Run time 40 min (Gradient mode) |
[23] |
0.1% aqueous Phosphoric acid (85%): Methanol (90:10) |
Daicel Chiral Phase Crown pack CR (+) |
0.3 - 6
|
Related substances |
[24] |
0.015 M Acetic acid: Methanol (95: 5) |
ODS |
6 - 90 |
Related substances |
[25] |
Mobile phase A: Phosphate buffer (KH2PO4): Methanol (90:10) Mobile phase B: Buffer: Methanol: Acetonitrile (50: 30:20) (pH 6.7 adjusted with Tri ethyl amine) |
Inertsil ZODS 3V
|
- |
Related substances Run time 65 min (Gradient mode) |
[26] |
Table 2: Review of liquid chromatographic methods.
The present review has presented some of the analytical techniques employed in the determination of Valacyclovir in various sample matrices. Of all the techniques, high performance liquid chromatographic techniques seem to be the techniques of interest.
Citation: Chodimella Sahitya Bharathi and Mukthinuthalapati Mathrusri Annapurna. “A Systematic Review on the Analytical Techniques for the Quantification of Valacyclovir". Acta Scientific Pharmaceutical Sciences 5.5 (2021): 51-55.
Copyright: © 2021 Chodimella Sahitya Bharathi and Mukthinuthalapati Mathrusri Annapurna. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.