Method Development and Validation of Cilazapril in Bulk Formulation by FC Reagent

 

Chavi Dagar*, G. Rohit Reddy, T. Ramesh

Department of Pharmaceutical Analysis and Quality Assurance, Vishnu Institute of Pharmaceutical Education and Research, Vishnupur, Narsapur, Medak, Telangana, India.

*Corresponding Author E-mail:

 

ABSTRACT:

A simple, sensitive, accurate, precise and economical visible Spectrophotometric method was developed and validated for the estimation of Cilazapril in Bulk form.  The method is based on the reaction of Cilazapril with FC Reagent [Folin Ciocalteu] in the presence of Sodium Carbonate producing blue colour which shows maximum absorbance at 725nm against reagent blank. The Chromogen obeyed Beer’s law in the concentration range of 10-50 µg/ml for Cilazapril. The results of the analysis have been validated statistically and recovery studies.

 

KEYWORDS: Cilazapril, FC Reagent, Sodium Carbonate, Visible Spectrophotometric.

 

 


INTRODUCTION:

Cilazapril is chemically (4s,7s)-7-[[(2s0-1-oxo-4-phenylbutan-2-yl]amino]-6-oxo1,2,3,4,7,8,9,10-octahydropyridazino[1,2-a] diazepine-4-carboxylic acid1. Cilazapril is an angiotensin-converting enzyme inhibitor (ACE inhibitor) used for the treatment of  hypertension and congestive heart failure.1 Literature survey reveals Spectrophotometric2-5 methods for estimation of Cilazapril in biological fluids and in pharmaceutical formulations. The present communication describes simple, sensitive, accurate, precise an economical visible spectrophotometric method using FC Reagent for the estimation of Cilazapril in bulk formulation.

 

 

 

Figure 1: Cilazapril structure

 

Mechanism of action: -

Cilazapril is an angiotensin-converting enzyme inhibitor used for the treatment of hypertension and congestive heart failure. Cilazapril suppress the rennin-angiotensin-aldosterrone system and there by reduces both supine and standing systolic and diastolic blood pressure.1

 

MATERIALS AND METHODS:

Apparatus:

A Shimadzu model T60 double beam UV/Vis Spectrophotometer with spectral width of 2nm wave length accuracy of 0.5 nm and a pair of 10mm matched quartz cells was used to measure absorbance of the resulting solutions.  Shimadzu analytical balance, an ultra sonic cleaner were used in the study.

 

Reagents and Materials:

Cilazapril drug was procured as a gift sample from Hetero drugs Ltd. Erragudda, Hyderabad, Telangana. Sodium Carbonate, Sodium tungstate, Sodium molybdate, phosphoric acid, Lithium Sulphate [A.R.Grade, SD Fine Chemicals Ltd., Mumbai] were used in the study.

 

Preparation of Reagent and Working standard stock solution:

10% Sodium Carbonate:

The solution was prepared by dissolving 10 gm of sodium carbonate in 100ml of distilled water.

 

Folin Ciocalteu Reagent:

Accurate weigh the 10gm of sodium tungstate and 2.5 gm of sodium molybdate taken in a conical flask to it add 70ml of water, 5ml of 85% phosphoric acid is added and 10ml of conc.  HCL is also added.  Reflux for 1 Hr.  Later add 15gm of Lithium Sulphate, 5ml of Water, 1 drop of bromine, reflux for 15 mins. Make up to 100 ml with water

 

Working Standard Stock Solution:

Accurate weigh the 100mg of pure drug and transferred in 100 ml of volumetric flask later diluted with distilled water upto100ml gives 1000µg/ml.

 

Methodology:

Different aliquots of working standard solution containing 10-50 µg/ml concentration of Cilazapril was transferred into series of volumetric flask. To it 1.5ml of Fc reagent and 5ml of 10% sodium carbonate was added and volume was made up to 10 ml with distilled water. The contents of the each flask was mixed well and allowed to stand at room temperature for 10 minutes. The absorbance of coloured species was measured at 725nm against reagent blank. The amount of drug present in the sample solution was computed from the calibration curve.

 

Reaction Mechanism:

The results obtained in this method were based on the condensation of Cilazapril with Folin Ciocalteu Reagent in the presence Sodium Carbonate producing blue coloured species which is measured at 725nm shown in the Figure 2.

 

Method Validation:

Linearity:

Five points calibration curve were obtained in a concentration range from 10-50 µg/ml for Cilazapril. The response of the drug was found to be linear in the investigation concentration range and the linear regression equation was y = 0.017X-0.013 with correlation coefficient 0.998 results are tabulated in table No.1 and Figure 3.

 

Precision:

Precision of the analytical method is ascertained by carrying out the analysis as per the procedure and as per normal weight taken for analysis. Repeat the analysis six times. Calculate the % assay, mean assay, % Deviation and % relative standard deviation and %RSD. The developed method was found to be precise as the %RSD values for the repeatability and intermediate precision studies were 0.69% and 0.85%, respectively shown results are tabulated in table No.2.

 

Accuracy:

Accuracy of the method is ascertained by standard addition method at 3 levels. Standard quantity equivalent to 50%, 100% and 150% is to be added in sample. The result shown that best recoveries (98.4-99.2%) of the spiked drug were obtained at each added concentration, indicating that the method was accurate and results are tabulated in table No.3.

 

Robustness:

Measure of the capacity of an analytical method to remain unaffected by small intentional variations in the operational parameters and provide an assurance of its reliability during the normal usage. It may be determined by various parameters like ph, flow rate, temperature etc. Robustness studies are performed during the method development stage. Results are tabulated in table No.4.

 

Sensitivity:

Limit of Detection and Quantitation (LOD and LOQ):- From the linearity data calculate the limit of detection and quantitation using the following formula.

 

LOD = 3.3σ / S

σ = Standard deviation of response.

S = Slope of the calibration curve of the analyte.

 

LOQ = 10σ / S

σ = Standard deviation of response.

S = Slope of the calibration curve of the analyte.

The results are tabulated in Table No.5.

 

RESULTS AND DISCUSSION:

The analytical method was developed by studying different parameters. The method was validated for all validation parameters as per ICH guidelines. The lambda max of Cilazapril was found to be 725 nm. Linearity was found with the concentration range 10-50 µg/ml and correlation coefficients found to be 0.998 indicate good linearity between concentration and slope area. Beer’s law was obeyed by the fundamental spectrum. This method was found to be simple, sensitive, accurate, precise and economical for routine analysis for the estimation of Cilazapril in Bulk form. Recovery studies were found to be close 99% indicated the accuracy and precision of the above two proposed methods. Values of LOD and LOQ were found to be 2.52 and 7.64 respectively. The accuracy and robustness was calculated to be 99.2 and 99.6%.

 

TABLE NO.1 – RESULT FOR LINEARITY

Concentration (µg/ml)

Absorbance

10

0.15

20

0.33

30

0.51

40

0.67

50

0.87

Slope

0.017

Intercept

0.013

Correlation

0.998

 

 

Figure 2: Reaction mechanism (λ max)

 

Figure 3: Linearity graph

 

TABLE NO.2 – RESULT FOR PRECISION

Sample No.

% Assay

Intra day

Inter day

10

98.7

99

20

99.3

99.8

30

100.2

97.3

40

100.7

98.6

50

99.6

99.3

Mean

99.7

98.8

SD

0.695

0.84

% RSD

0.697

0.85

 

TABLE NO.3 – RESULT FOR ACCURACY

% Recovery Level

% Recovery

Mean

SD

%RSD

 

50%

98.5

 

98.8

 

0.24

 

0.25

99.1

98.9

 

100%

97.5

 

98.4

 

0.68

 

0.69

98.9

99

 

150%

99.8

 

99.2

 

0.543

 

0.547

98.5

99.4

 


TABLE NO.4 – RESULT FOR ROBUSTNESS

Parameter

Amount of Cephalexin(µg/ml)

 % Recovery

SD

%RSD

Taken

Found

1 ml of Volume of FC Reagent and 4ml of 10%sodium carbonate

20

19.9

99.6

0.53

0.54

50

49.2

98.5

 


TABLE NO.5 RESULT FOR LOD AND LOQ

LOD ((µg/ml)

2.52

LOQ ((µg/ml)

7.64

 

CONCLUSION:

The proposed visible spectrophotometric method was found to be simple, sensitive, accurate, precise and economic for determination of Cilazapril in bulk formulation.  Hence it can be conveniently adopted for routine quality analysis of drug in pharmaceutical dosage form.

 

ACKNOWLEDGMENTS:

The authors are thankful to the Head of the Pharmaceutical Analysis Department and my guide for his moral support and encouragement during the work and to the Hetero drugs Pvt.Ltd. Erragadda, Hyderabad, Telangana, India for providing the necessary facilities to carry out this research.

REFERENCES:

1.       Szucs, T. (1991). "Cilazapril. A review". Drugs. 41 Suppl 1: 18–24.

2.       Gumieniczeka A, Przyborowski L. Determination of benazepril and cilazapril in pharmaceuticals by high performance liquid chromatography. Journal of Liquid Chromatography, 1997, 20 (13), 2135-2142.

3.       Chavi Dagar, G.Rohit Reddy * and VVS. Rajendra Prasad - Development and Validation of Visible Method for estimation of Cilazapril in bulk formulation by MBTH reagent- Asian Journal of Pharmaceutical Analysis.

4.       Chavi Dagar, G.Rohit Reddy * and VVS. Rajendra Prasad - Development and Validation of Visible Method for estimation of Cilazapril in bulk formulation. World Journal of Pharmaceutical Research.

5.       G.Rohit Reddy *, Rakesh Goud, Hrudaya Ranjani and VVS. Rajendra Prasad- A New Colorimetric Development and Validation of Visible Method for estimation of Diclofenac in bulk formulation International Journal of Pharmaceutical Research and Analysis Vol 7 / Issue 1/ 2017/ 1-4.

 

 

 

 

 

 

 

 

Received on 05.03.2018       Accepted on 15.04.2018     

© Asian Pharma Press All Right Reserved

Asian J. Pharm. Ana. 2018; 8(2): 83-85.

DOI: 10.5958/2231-5675.2018.00016.9