Development and Validation of Analytical Method for Aripiprazole and

Escitalopram Oxalate by Simultaneous Equation Spectroscopic Method

 

Divya Solanki1,2*, Hasumati Raj2, Neelam Prajapati2

1Research Scholar 2014, Gujarat Technological University, Gujarat

2Quality Assurance Department, Shree Dhanvantary Pharmacy College, Kim, Surat

*Corresponding Author E-mail: divyasolanki844@gmail.com

 

 

ABSTRACT:

A simple, accurate and precise spectroscopic method was developed for simultaneous estimation of Aripiprazole and Escitalopram Oxalate in synthetic mixture using simultaneous equation Method. In this spectroscopic method, 255.00 nm and 238.00 nm wavelengths were selected for measurement of absorptivity. Both the drugs show linearity in a concentration range of 5-30 μg/ml and 15-75 μg/ml at their respective λmax. Accuracy, precision and recovery studies were done by QC samples covering lower, medium and high concentrations of the linearity range. The relative standard deviation for accuracy, precision studies were found to be within the acceptance range (<2%). The limit of determination was 0.129 and 0.223μg/ml Aripiprazole and Escitalopram Oxalate, respectively. The limit of quantification was 0.392 and 0.677 for Aripiprazole and Escitalopram Oxalate, respectively. Recovery of Aripiprazole and Escitalopram Oxalate in were found to be 100.66 % and 100.70 % respectively confirming the accuracy of the proposed method. The proposed method  is recommended for routine analysis since they are rapid, simple, accurate and also sensitive and specific by no heating and no organic solvent extraction.

 

KEYWORDS: Aripiprazole, Escitalopram Oxalate, simultaneous estimation, Simultaneous equation  method, analysis method.

 

 


1. INTRODUCTION:

Aripiprazole is a psychotropic agent belonging to the chemical class of benzisoxazole derivatives and is indicated for the treatment of schizophrenia. Aripiprazole is a selective monoaminergic antagonist with high affinity for the serotonin Type 2 (5HT2), dopamine Type 2 (D2), 1 and 2 adrenergic, and H1 histaminergic receptors. Aripiprazole's antipsychotic activity is likely due to a combination of antagonism at D2 receptors in the mesolimbic pathway and 5HT2A receptors in the frontal cortex.

 

Antagonism at D2 receptors relieves positive symptoms while antagonism at 5HT2A receptors relieves negative symptoms of schizophrenia. IUPAN name of Aripiprazole is7-[4-[4-(2,3-Dichlorophenyl)-1-piperazinyl]butoxy]-3,4-dihydro-2(1H)-quinolinone(1).

 

Figure:1   Structure of  aripiprazole  (2)

 

Aripiprazole is white, crystalline solid powder. Solubility is given in practically soluble in chloroform and ethanol (3-4).

 

Escitalopram Oxalate is selective serotonin reuptake inhibitors (SSRIs) are a group of chemically diverse antidepressant drugs that specifically inhibit serotonin reuptake. The SSRIs block the reuptake of serotonin, leading to increased concentrations of the neurotransmitter in the synaptic cleft and, ultimately, to greater postsynaptic neuronal activity. The combination of both have decrease dose and improve Depression. IUPAN name of Escitalopram Oxalate 1-[3-(Dimethylamino) propyl]-1-(4fluorophenyl)-1,3-dihydro-5-isobenzofuran-carbonitrile oxalate(5).

 

Figure 2: Structure of Escitalopram Oxalate (6)

 

Escitalopram Oxalate is white, crystalline solid powder. Solubility is given in practically soluble in methanol(7-8).

 

The review of literature regarding quantitative analysis of Aripiprazole and Escitalopram Oxalate revealed that no Simultaneous Equation method attempt was made to develop analytical methods for Aripiprazole and Escitalopram Oxalate.  Some spectrometric methods and chromatographic methods have been reported for the estimation of the individual and combination of drugs(9-14).The focus of the present study was to develop and validate a rapid, stable, specific, and economic Spectroscopic method for the estimation of Aripiprazole and Escitalopram Oxalate in Synthetic Mixture.

 

1.1. Theory:

We can find out concentration of both the drug from combination mixture using the simultaneous equation method. In this method using the absorbance of both the drug and mixture at their wavelength and put this value in following equation and we can find out the concentration of drugs present in combination.

 

            (A2 × Ay1) – (A1 × Ay2)

Cx = ---------------------------------      ------ (1)

         (Ay1 × Ax2) – (Ay2 × Ax1)

 

          (A1 × Ax2) – (A2 × Ax1)

Cy = ---------------------------------      ------ (2)

          (Ax2 × Ay1) – (Ax1 × Ay2)

Where,

Cx= Concentration of drug ESC

Cy = Concentration of drug ARI

A1 = Absorbanceof mixture at wavelength   238 nm

A2 = Absorbance of mixture at wavelength   255nm

Ax1 = Absorptivity of drug A at wavelength   238 nm

Ax2 = Absorptivity of drug A at wavelength   255nm

 

Ay1 = Absorptivity of drug B at wavelength 238 nm

Ay2 = Absorptivity of drug B at wavelength 255nm

 

2. MATERIALS AND METHODOLOGY:

2.1. Apparatus

A double beam UV/Visible spectrophotometer (Shimadzu model 2450 , Japan) with spectral width of 2nm, 1 cm quartz cells was used to measure absorbance of all the solutions. Spectra were automatically obtained by UV-Probe system software.

2.2. Reference samples

Aripiprazole and Escitalopram Oxalate received as gift sample from Cadila Healthcare Limited, GIDC Estate ankleshwar.

2.3. Materials and reagents

Methanol AR grade (RANKEM)

 

2.4. Preparation of Standard Solution and Synthetic Mixture

2.4.1 Preparation of stock Solution of Aripiprazole:

·      An accurately weighed quantity equivalent to 10mg of Aripiprazole was transferred to 100 ml volumetric flask made up to the mark with the methanol to obtain standard solution having concentration of ARI (100μg/ml).

·       

2.4.2 Preparation of standard stock solution of Escitalopram Oxalate:

·      An accurately weighed quantity of ESC (10 mg) was transferred to a separate 100 ml volumetric flask and dissolved and diluted to the mark with methanol to obtain standard solution having concentration of ESC (100μg/ml).

·       

2.4.3. Preparation of Standard Mixture Solution (ARI+ ESC):

·      1 ml of working standard stock solution of ARI (100μg/ml) and 3ml of standard Stock solution of ESC (100μg/ml) were pipetted out into 10ml volumetric flask and volume was adjusted to the mark with methanol to get 10μg/ml of ARI and 30μg/ml of ESC.

·       

2.4.4 Preparation of Test Solution

Weigh Synthetic mixture equivalent to 10 mg of Aripiprazole taken in 100ml Volumetric Flask, dissolved in 25 ml of Methanol, Sonicated for 15min,  diluted with 100 ml Methanol. Take 0.5, 1.0, 1.5, 2.0, and 2.5  ml and diluted with 10ml Methanol to make concentration 5, 10, 15, 20 and 25µg/ml of ARI and 15, 30, 45, 60 and 75µg/ml of ESC.


 

Figure 3 Overlainzero order spectra of ARI and ESC (1:3) ratio, respectively

 


2.5   Procedure

Calibration curves for Escitalopram Oxalate:

This series consisted of five concentrations of standard ARI solution ranging from 5-25μg/ml. The solutions were prepared by pipette out Standard ARI stock solution (0.5ml, 1.0ml, 1.5ml, 2.0ml and 2.5ml) was transferred into a series of 10 ml volumetric flask and volume was adjusted up to mark with Methanol.  A zero order spectrum measured the absorbance at 255.00nm against a reagent blank solution (methanol).

 

Calibration curve for Aripiprazole:

This series consisted of five concentrations of standard ESC solution ranging from 15-75μg/ml. The solutions were prepared by pipette out Standard ESC stock solution (1.5ml, 3.0ml, 4.5ml, 6.0ml and 7.5 ml) was transferred into a series of 10 ml volumetric flask and volume was adjusted up to mark with Methanol. A zero order spectrum, measured the absorbance at 238.00nm against a reagent blank solution (methanol).

 

3. RESULTS AND DISCUSSION:

Validation Parameters

3.1 Linearity

Six point calibration curves were obtained in the concentration range of 5-25μg/ml for Aripiprazole and 15-75μg/ml for Escitalopram Oxalate. The response of drug was found to be linear in investigation range and the regression equations was found to be y = 0.033x - 0.035 for ARI (n=6), y = 0.038x + 0.095 for ESC (n=6), with the correlation coefficient 0.999 and 0.999 (n=6) respectively, is listed in Table 1.


 

Table.1 Calibration data for ari and esc at 255.00nm and 238.00nm, respectively. *(n=6)

Sr.No

Escitalopram

Oxalate μg/ml 

Absorbance ± SD   (n=6) (238nm)

%RSD

Aripiprazole

μg/ml

Absorbance±S.D. (n=6) (255 nm)

%RSD

1

15

0.639±0.001

0.307

5

0.14±0.0009

0.665

2

30

1.270±0.001

0.160

10

0.292±0.002

0.762

3

45

1.807±0.010

0.571

15

0.46±0.001

0.253

4

60

2.407±0.016

0.665

20

0.627±0.002

0.334

5

75

2.933±0.023

0.793

25

0.807±0.005

0.723

 

FIG. 5 Calibration curve for ESC at 238.00nm and Aripiprazole AT 255nm


3.2 Precision:

I. Intraday precision:

The precision of the developed method was assessed by analyzing combined standard solution containing three different concentrations 30, 45, 60μg/ml for ESC and 10, 15, 20μg/ml ARI. Three replicate (n=3) each on same day. Intraday precision data presented in Table (A). These% RSD value was found to be less than 1.0 indicated that the method is precise.

 

 

Table (A) Intraday precision data for estimation of ESC and ARI (n=3)

Conc.

(μg/ml)

Escitalopram Oxalate + Aripiprazole

ESC +

ARI

Absorbance

(238nm)

%RSD

Absorbance (255nm)

%RSD

30:10

1.58

0.630

0.466

0.643

45:15

2.30

0.860

0.793

0.126

60:20

2.91

0.343

1.04

0.960

 

 

II. Interday precision

The precision of the developed method was assessed by analyzing combined standard solution  containing three different concentrations 30, 45, 60μg/ml for ESC and 10, 15, 20μg/ml ARI triplicate (n=3) per day for consecutive 3 days for inter-day precision. Interday precision data presented in Table B. These %RSD value was found to be less than 1.0 indicated that the method is precise.

3.3 Accuracy:

Composition of synthetic mixture

The preparation of synthetic mixture was as per patent:

·      Aripiprazole: 50 mg

·      Escitalopram Oxalate: 150 mg

·      Starch: 1310 mg

·      Magnesium Stearate: 40 mg

·      Lactose : 950 q.s

·      From the Synthetic Mixture weigh accurately equivalent about 10mg of ARI. Take Four 100ml Volumetric Flask and in each flask add synthetic mixture equivalent to 10mg of ARI. Flask 1 form as a Placebo and remaining flask 2, 3,4 spike with 80, 100, 120%. Same way spike ESC in respectively flask. dissolved in 25 ml Methanol and Sonicated for 15min. make up the volume with methanol . The solution was filtered through Whatman filter paper No. 42.

·      Finally the solution had concentration 100μg/ml for ARI and 300μg/ml for ESC. From that pipette out 0.5 ml in 10 ml volumetric flask and volume was made up to mark with Methanol to make final concentration ARI (5 µg/ml) and ESC (15 µg/ml).

Data from nine determinations over three concentration levels covering the specified range was determined and % recovery was calculated.


 

Table (B) Interday precision data for estimation of ESC and ARI (n=3)

Conc. (μg/ml)

Escitalopram Oxalate + Aripiprazole

ESC

ARI

Absorbance (238nm)

% RSD

Absorbance (255 nm)

% RSD

30:10

1.57

0.732

0.471

0.760

45:15

2.28

0.910

0.793

0.262

60:20

2.91

0.524

1.043

0.961

 

Amount of Formulation (mg)

Amount of API Spiking (mg)

Total Amount (mg)

ESC

ARI

ESC

ARI

ESC

ARI

30

10

-

-

30

10

30

10

24

8

54

18

30

10

30

10

60

20

30

10

36

12

66

22

 

Recovery data of ESC and ARI *(n=3)

% Recovery

Total Conc.

Conc. found (µg/ml)

% Recovery  ± SD

% RSD

 

ESC

ARI

ESC

ARI

ESC

ARI

ESC

ARI

Control

15

5

15.07 

5.07

100.29 ±0.321

101.40±0.871

0.320

0.859

80%

27

9

27.11

9.07

100.96±0.756

101.83±0.803

0.749

0.789

100%

30

10

30.26

10.03

101.73±0.070

100.62±0.970

0.068

0.964

120%

33

11

32.89

10.97

99.42±0.393

99.55±0.975

0.393

0.979

 

 


3.4   Limit of Detection and Limit of Quantification

The Limit of detection and quantitation of the developed method was assessed by analyzing 10 replicates of standard solutions containing concentrations 15μg/ml for ESC and 5μg/ml for ARI.

The LOD and LOQ were calculated as LOD = 3.3*σ/S, and LOQ = 10*σ/S, where σ is the standard deviation of the lowest standard concentration and S is the slope of the standard curve.


 

 

 

LOD and LOQ value of ESC and ARI (n=3)

Drugs

LOD (µg/ml)

LOQ (µg/ml)

Escitalopram Oxalate  + Aripiprazole

238 nm

0.223

0.677

255 nm

0.129

0.392

 

Robustness of ESC and ARI (n=3)

Parameters

 

238nm (esc)

RSD

ARI (255nm)

RSD

Different instrument

Inst. 1

1.580±0.010

0.632

0.469±0.003

0.639

Inst. 2

1.570±0.010

0.636

0.472±0.002

0.423

Different analyst

Analyst 1

1.580±0.010

0.632

0.465±0.001

0.215

Analyst 2

1.570±0.010

0.636

0.463±0.001

0.249

 

 


3.5 Robustness:

·      Robustness of the method was determined by subjecting the method to slight change in the method condition, individually, the :

·      Change in instrument (UV-Vis Spectrophotometer model 1800 and 2450).

·      Change Analyst

% RSD was calculated.

 

3.6 Ruggedness

·      Ruggedness of the method was determined by subjecting the method to slight change in the method condition, individually, the :

·      Change in Wavelength from 238.00 and 255.00 to 238±2 and 255±02.

·      Change Ratio

·      Change Solvent

·      Three replicates were made for the same concentration

·      % RSD was calculated.


 

Ruggedness of ESC and ARI (n=3)

Parameter

 

238nm (ESC)

%RSD

255nm(ARI)

%RSD

Change wavelength

240 and 257   nm

1.580±0.010

0.632

0.463±0.001

0.329

236 and 253 nm

1.553±0.015

0.743

0.475±0.001

0.210

Change Ratio

1:3

1.580±0.010

0.632

0.468±0.001

0.213

3:1

0.952±0.001

0.105

0.921±0.001

0.108

1:2

1.042±0.001

0.146

0.399±0.001

0.382

2:1

0.755±0.001

0.132

0.625±0.001

0.244

Solvent change

2 % Water

1.465±0.001

0.104

0.467±0.001

0.326

5 %  Water

1.407±0.001

0.108

0.444±0.003

0.851

 

 

 


4. Application of the proposed method for analysis of ari and esc in synthetic mixture

The preparation of synthetic mixture as per patent:

·      Aripiprazole: 50 mg

·      Escitalopram Oxalate: 150 mg

·      Starch: 1310 mg

·      Magnesium Stearate: 40 mg

·      Lactose : 950 q.s

 

From the Synthesis Mixture weigh accurately equivalent about 10mg of ARI in 100ml Volumetric Flask dissolve in 25ml of Methanol. Sonicate for 15 min. Dilute up to the 100 ml with Solvent. Shake vigorously; filter the solution and further Dilution.

 

Finally the solution had the concentration 100PPM and 300PPM respectively for ARI and ESC. After that from this solution 0.5ml was pipette out and diluted up to 10 ml with Methanol. So the concentration was 15 PPM and 5 PPM for ESC and ARI respectively.


Table 8   Analysis data of Synthetic Mixture*(n=3)

Drugs

% Assay ± SD

% RSD(n=3)

Escitalopram Oxalate +  Aripiprazole

(238nm)

100.29 ± 0.321

0.320

(255nm)

101.40 ± 0.87

0.859

 

Summary Table:

TABLE.9   Summary of Validation Parameters

SR. NO.

PARAMETER

Escitalopram Oxalate

Aripiprazole

1

Wave length Max.

238.00nm

255.00nm

2

Linearity  (µg/ml) (n=6)

15-75 µg/ml

5-25 µg/ml

3

Regression equation

y = 0.038x + 0.095

y = 0.033x - 0.035

4

Correlation coefficient (r2)

0.999

0.999

5

Accuracy(%Recovery) (n=3)

100.70

100.66

6

Precision

Intra-day (%RSD)(n=3)

Inter-day (%RSD)(n=3)

 

0.343 -  0.860

0.262 – 0.961

 

0.126 – 0.960

0.524 – 0.910

7

LOD  (µg/ml)   (n=10)

0.223

0.129

8

LOQ (µg/ml)  (n=10)

0.677

0.392

9

Robustness and Ruggedness     (%RSD)

0.104-0.743

0.108 -0.851

10

Assay

100.29%

101.40%

 


5. CONCLUSION:

A new, Simultaneous Equation method has been developed for estimation of Aripiprazole and Escitalopram Oxalate. The method was validated by employment of ICH (15)guidelines. The validation data is indicative of good precision and accuracy, and prove the reliability of the method. The method involves the generation of absorbance spectra followed by measurement of the absorbance. The proposed method does not require any sophisticated mathematical treatment for the absorption data, and it exhibits several advantages over other Spectrophotometric methods for resolution of binary mixtures. Therefore, the presented methodology is adequate for the routine quality control analysis of these fixed-dose combinations.

 

6. CONFLICT OF INTEREST:

The authors confirm that this article content has no conflict of interest.

 

7. ACKNOWLEDGEMENT:

We are sincerely thankful to Shree Dhanvantary Pharmacy College, Kim, Surat, for providing us Infrastructure facilities and moral support to carry out this research work. We are also thankful to SDPARC for giving us their special time and guidance for this research work. We also thank our colleagues for their helping hand.

 

8. REFERANCE:

1.     Aripiprazole mechanism :information available from drug bank: http://www.drugbank.ca/drugs/DB01238

2.     Aripiprazole Drug info (database available on internet): Drug Bank: Available from : http://www.drugbank.ca/drugs/DB01238

3.     Aripiprazole Drug info (database available on internet): lookchem: Available from :  http://www.lookchem.com/Aripiprazole/

4.     Aripiprazole Drug info (database available on internet):  Wikipedia. Available from :  https://en.wikipedia.org/wiki/Aripiprazole

5.     Harvey Richard A and Champe Pamela C, Lippincott Williams and Wilkins Pharmacology; 4th Edn; Walters Kluwer Florida, 2009, pp 142.  

6.     Escitalopram Oxalate Drug info (database available on internet) http://www.chemicalbook.com/ChemicalProductProperty_EN_CB5712919.  html

7.     Escitalopram Oxalate Drug info (database available on internet):  http://www.scbt.com/datasheet-208365-s-citalopramoxalate.html

8.     Escitalopram Oxalate Drug info (database available on internet): Wikipedia. Available from:   https://en.wikipedia.org/wiki/Escitalopram.

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13.   Syama SB, “Development and Validation of Liquid Chromatographic Method for Estimation of Escitalopram Oxalate in Tablet Dosage Forms.” Int. J. Bio. Sci. 2011, 2(1), 140-146.

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Received on 21.02.2016       Accepted on 14.03.2016     

© Asian Pharma Press All Right Reserved

Asian J. Pharm. Ana. 6(1): January- March, 2016; Page 41-46

DOI: 10.5958/2231-5675.2016.00007.7