Chiguru Vishnu Vardhan - Academia.edu (original) (raw)
Papers by Chiguru Vishnu Vardhan
Analytical Methods, 2014
An isocratic reversed phase ultra performance liquid chromatography (RP-UPLC) method was develope... more An isocratic reversed phase ultra performance liquid chromatography (RP-UPLC) method was developed for screening counterfeit medicines with UV detection at 210 nm.
Chromatographia, 2013
The present study describes a convenient method for the separation and simultaneous determination... more The present study describes a convenient method for the separation and simultaneous determination of eight drugs used in cardiovascular diseases, viz., atenolol (ATN), lisinopril (LISI), hydrochlorothiazide (HCTZ), enalapril maleate (ENA), amlodipine besylate (AMLO), losartan potassium (LOSA), valsartan (VAL) and atorvastatin calcium (ATOR) in pharmaceutical formulations. A ZORBAX Rx-C8 column (250 × 4.6 mm, 5 μm particle size) was used with mobile phase consisting of acetonitrile, 10 mM dipotassium hydrogen phosphate buffer (pH 2.2 adjusted with orthophosphoric acid) using a gradient program and quantitative evaluation was performed at 210 nm with a flow rate of 1.0 mL min−1. Suitability of this method for the quantitative determination of the drugs was proved by validation in accordance with International Conference on Harmonization guidelines. The method is selective, precise, robust, accurate and can be used for routine analysis of 15 combination pharmaceutical formulations in quality control.
▼ A sensitive UPLC positive ion electrospray tandem mass spectrometry method was developed and va... more ▼
A sensitive UPLC positive ion electrospray tandem
mass spectrometry method was developed
and validated for identifi cation of degradation
products of sitagliptin formed during stress
study. 6 of the major degradants were identifi
ed with the proposed method. The separation
of sitagliptin and its degradation products
was achieved on a Acquity BEH C-18 column
(50 × 2.1 mm, 1.7 μm) using a gradient programme.
The mobile phase consists of solvent A (10 mM
ammonium formate, pH 6.4 adjusted with formic
acid) and solvent B (acetonitrile) and quantitative
evaluation was performed at 267 nm with
a fl ow rate of 0.15 mL min − 1 . Suitability of this
method for the quantitative determination of the
drugs was proved by validation in accordance
with International Conference on Harmonization
(ICH) guidelines and can be used for routine
analysis of sitagliptin formulations in quality
control.
The present study describes a convenient method for the separation and simultaneous determination... more The present study describes a convenient
method for the separation and simultaneous determination
of eight drugs used in cardiovascular diseases, viz., atenolol
(ATN), lisinopril (LISI), hydrochlorothiazide (HCTZ),
enalapril maleate (ENA), amlodipine besylate (AMLO),
losartan potassium (LOSA), valsartan (VAL) and atorvastatin
calcium (ATOR) in pharmaceutical formulations.
A ZORBAX Rx-C8 column (250 9 4.6 mm, 5 lm particle
size) was used with mobile phase consisting of acetonitrile,
10 mM dipotassium hydrogen phosphate buffer (pH 2.2
adjusted with orthophosphoric acid) using a gradient program
and quantitative evaluation was performed at 210 nm
with a flow rate of 1.0 mL min-1. Suitability of this
method for the quantitative determination of the drugs was
proved by validation in accordance with International
Conference on Harmonization guidelines. The method is
selective, precise, robust, accurate and can be used for
routine analysis of 15 combination pharmaceutical formulations
in quality control.
An isocratic reversed phase ultra performance liquid chromatography (RP-UPLC) method was develope... more An isocratic reversed phase ultra performance liquid chromatography (RP-UPLC) method was developed for screening counterfeit medicines with UV detection at 210 nm. Chromatographic separation was performed on a Waters BEH C-18 column (50 Â 2.1 mm, i.d., 1.7 mm particle size) with isocratic elution of a mobile phase containing a mixture of acetonitrile-methanol-ammonium formate buffer (0.01 M) (31 : 30.5 : 38.5 v/v/v) with a flow rate of 0.4 mL min À1 and pH 3 (adjusted with formic acid). A mixture design methodology was selected for the optimization and validation of the mobile phase composition.
Analytical Methods, 2014
An isocratic reversed phase ultra performance liquid chromatography (RP-UPLC) method was develope... more An isocratic reversed phase ultra performance liquid chromatography (RP-UPLC) method was developed for screening counterfeit medicines with UV detection at 210 nm.
Chromatographia, 2013
The present study describes a convenient method for the separation and simultaneous determination... more The present study describes a convenient method for the separation and simultaneous determination of eight drugs used in cardiovascular diseases, viz., atenolol (ATN), lisinopril (LISI), hydrochlorothiazide (HCTZ), enalapril maleate (ENA), amlodipine besylate (AMLO), losartan potassium (LOSA), valsartan (VAL) and atorvastatin calcium (ATOR) in pharmaceutical formulations. A ZORBAX Rx-C8 column (250 × 4.6 mm, 5 μm particle size) was used with mobile phase consisting of acetonitrile, 10 mM dipotassium hydrogen phosphate buffer (pH 2.2 adjusted with orthophosphoric acid) using a gradient program and quantitative evaluation was performed at 210 nm with a flow rate of 1.0 mL min−1. Suitability of this method for the quantitative determination of the drugs was proved by validation in accordance with International Conference on Harmonization guidelines. The method is selective, precise, robust, accurate and can be used for routine analysis of 15 combination pharmaceutical formulations in quality control.
▼ A sensitive UPLC positive ion electrospray tandem mass spectrometry method was developed and va... more ▼
A sensitive UPLC positive ion electrospray tandem
mass spectrometry method was developed
and validated for identifi cation of degradation
products of sitagliptin formed during stress
study. 6 of the major degradants were identifi
ed with the proposed method. The separation
of sitagliptin and its degradation products
was achieved on a Acquity BEH C-18 column
(50 × 2.1 mm, 1.7 μm) using a gradient programme.
The mobile phase consists of solvent A (10 mM
ammonium formate, pH 6.4 adjusted with formic
acid) and solvent B (acetonitrile) and quantitative
evaluation was performed at 267 nm with
a fl ow rate of 0.15 mL min − 1 . Suitability of this
method for the quantitative determination of the
drugs was proved by validation in accordance
with International Conference on Harmonization
(ICH) guidelines and can be used for routine
analysis of sitagliptin formulations in quality
control.
The present study describes a convenient method for the separation and simultaneous determination... more The present study describes a convenient
method for the separation and simultaneous determination
of eight drugs used in cardiovascular diseases, viz., atenolol
(ATN), lisinopril (LISI), hydrochlorothiazide (HCTZ),
enalapril maleate (ENA), amlodipine besylate (AMLO),
losartan potassium (LOSA), valsartan (VAL) and atorvastatin
calcium (ATOR) in pharmaceutical formulations.
A ZORBAX Rx-C8 column (250 9 4.6 mm, 5 lm particle
size) was used with mobile phase consisting of acetonitrile,
10 mM dipotassium hydrogen phosphate buffer (pH 2.2
adjusted with orthophosphoric acid) using a gradient program
and quantitative evaluation was performed at 210 nm
with a flow rate of 1.0 mL min-1. Suitability of this
method for the quantitative determination of the drugs was
proved by validation in accordance with International
Conference on Harmonization guidelines. The method is
selective, precise, robust, accurate and can be used for
routine analysis of 15 combination pharmaceutical formulations
in quality control.
An isocratic reversed phase ultra performance liquid chromatography (RP-UPLC) method was develope... more An isocratic reversed phase ultra performance liquid chromatography (RP-UPLC) method was developed for screening counterfeit medicines with UV detection at 210 nm. Chromatographic separation was performed on a Waters BEH C-18 column (50 Â 2.1 mm, i.d., 1.7 mm particle size) with isocratic elution of a mobile phase containing a mixture of acetonitrile-methanol-ammonium formate buffer (0.01 M) (31 : 30.5 : 38.5 v/v/v) with a flow rate of 0.4 mL min À1 and pH 3 (adjusted with formic acid). A mixture design methodology was selected for the optimization and validation of the mobile phase composition.