Estimation of Emtricitabine by Extractive Colorimetric Methods in Bulk and Pharmaceutical Dosage Form

 

Rajan V. Rele, Prathamesh P. Tiwatane

Central Research Laboratory, D.G. Ruparel College, Matunga, Mumbai 400016.

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

 

ABSTRACT:

Simple sensitive and accurate extractive spectrophotometric methods have developed for the estimation of emtricitabine in pharmaceutical dosage form. The methods are based on the formation of coloured complexes by the drug with reagents like bromophenol blue, solochrome dark blue and bromocresol green in acidic medium. The ion associated complexes were formed and quantitatively extracted under the experimental condition in chloroform. The absorbance values were measured at 420nm, 495nm and 430nm respectively. The proposed methods were validated statistically. Recoveries of methods were carried out by standard addition methods. The linearity was found to be 1-10μg/ml, 2 -12μg/ml, 1-14μg/ ml for methods 1, 2 and 3 respectively. The low values of standard deviation and percentage RSD indicate high precision of methods. Hence these methods are useful for routine estimation of emtricitabine in tablets.

 

KEYWORDS: Emtricitabine, Bromophenol Blue, Solochrome Dark Blue, Bromocresol Green, Chloroform.

 

 


INTRODUCTION:

It is a 4-amino-5-fluoro-1-[(2R,5S)-2 (hydroxyl -methyl)-1,3-oxathiolan-5-yl]-1,2-dihydro- pyrimidin-2-one. Emtricitabine is a nucleoside reverse transcriptase inhibitor (NRTI) for the treatment of HIV infection in adults. EMT is an analogue of cytidine. The drug works by inhibiting reverse transcriptase, the enzyme that copies HIV RNA into new viral DNA.

 

According to the literature review several methods has been developed for drug, like spectroscopy methods1-6. HPLC7-22, and HPTLC23, 24. These spectroscopy methods can be used for the routine analysis. In the proposed methods optimization and validation of this method are reported.

 

Structure of   Emtricitabine:

 

MATERIALS AND METHODS:

A Shimadzu -160 A double beam UV-Visible recording spectrophotometer with pair of 10mmmatched quartz cell was used to measure absorbance of solutions. A Shimadzu analytical balance was used.

 

Bromophenol blue, solochrome dark blue, bromocresol green, hydrochloric acid, potassium hydrogen phthalate and chloroform of A.R. grade were used in the study.

 

Preparation of Standard Solution and Reagents:

Stock solution of Emtricitabine (100μg/ml) was prepared in distilled water. From this stock solution working standard (10μg/ml) was prepared by diluting 10ml stock solution to 100ml with distilled water. 0.6% w/v solution of bromophenol blue, 0.25% w/v solochrome dark blue and 0.2% w/v bromocresol green were prepared in distilled water respectively.

Potassium hydrogen phthalate buffer solution of pH 4.01was prepared in distilled water. Dilute hydrochloric acid was used to adjust desired pH of buffer solution.

 

EXPERIMENTAL:

Method 1 (with bromophenol blue):

Into a series of separating funnels appropriate amount of the working standard drug solutions were pipetted out. To each funnel 1.0ml of buffer (pH= 4.0) and 6ml of 0.6 % w/v bromophenol blue were added. 10ml of chloroform was added to each funnel. The solutions were shaken for thorough mixing of the two phases and were allowed to stand for clear separation of the layers. The absorbance values of the chloroform layers were measured against their respective reagent blank at the wavelength of the maximum absorbance (λ max 420 nm).

 

Method 2 (with Solochrome dark blue):

Into a series of separating funnels appropriate amount of the working standard drug solutions were pipetted out. To each funnel 4. ml of buffer (pH = 1.20) and 4ml of 0.25% w/v solochrome dark blue were added. 10ml of chloroform was added to each funnel. The solutions were shaken for thorough mixing of the two phases and were allowed to stand for clear separation of the layers. The absorbance values of the chloroform layers were measured against their respective reagent blank at the wavelength of the maximum absorbance (λ max=495 nm).

 

Method 3 (with bromocresol green):

Into a series of separating funnels appropriate amount of the working standard drug solutions were pipetted out. To each funnel 1.0ml of buffer (pH= 3.8) and 5.0ml of 0.02% w/v bromocresol green were added. 10ml of chloroform was added to each funnel. The solutions were shaken for thorough mixing of the two phases and were allowed to stand for clear separation of the layers. The absorbance values of the chloroform layers were measured against their respective reagent blank at the wavelength of the maximum absorbance (λmax =430 nm).

 

Estimation from Tablets:

Twenty tablets were weighed accurately and average weight of each tablet was determined. Powder equivalent to 10mg of Emtricitabine was weighed and transferred in 100ml of volumetric flask. A 30ml of distilled water was added and sonicated for 15 minutes and filtered. The filtrate and washing were diluted up to the mark with distilled water to give concentration as 100μg/ml. Such solution was used for analysis.

 

Table 1: Values of results of optical and regression of drug

Parameter

Bromophenol Blue

Solochrome Dark Blue

Bromocresol Green

Detection Wavelength (nm)

420

495

430

Beer Law Limits (µg/ml)

1-10

2-12

1-14

Correlation coefficient (r2)

0.9999

0.9996

0.9998

Regression equation (y=b+ac)

 

 

 

Slope (a)

0.0601

0.0154

0.0251

Intercept (b)

0.0011

-0.0003

0.0014

 

RESULTS:

The extractive spectrophotometric methods are popular due to their sensitivity in assay of the drug and hence ion pair extractive spectrophotometric methods have gain considerable attention for quantitative determination of many pharmaceutical preparations. These proposed methods are extractive spectrophotometric methods for the determination of emtricitabine by using chloroform as solvent from its formulations i.e., tablets. The colour ion pair complexes formed are very stable. The working conditions of these methods were established by varying one parameter at time and keeping the other parameters fixed by observing the effect produced on the absorbance of the colour species. The various parameters involved for maximum colour development for these methods were optimized. The proposed methods were validated statistically and by recovery studies. The molar absorptivity shows the sensitivity of methods while the precision was confirmed by %RSD (relative standard deviation). The optical characteristics such as absorption maxima (nm), molar absorptivity (l -mole-1 cm-1), co-relation coefficient (r) were calculated and are also summarized. Assay results of recovery studies are given in table 2 (A, B, C).

 


Table no 2: A (bromophenol blue)

Amount of Sample Added in (µg/ml)

Amount of Standard Added in (µg/ml)

Total amount recovered

Percentage recovery (%)

Standard deviation

Percentage of relative standard deviation (C.O.V.)

1

0

1.01171

101.171

0.012392

1.224885

2

1

2.002342

100.1171

0.017525

0.875241

3

2

2.990632

99.68774

0.015998

0.534949

4

3

4.000937

100.0234

0.01628

0.406901

 

 

 

 

Mean= 0.01554

Mean= 0.760494


Table no 2: B (solo chrome dark blue)

Amount of Sample Added in (µg/ml)

Amount of Standard Added in (µg/ml)

Total amount recovered

Percentage recovery (%)

Standard deviation

Percentage of relative standard deviation (C.O.V.)

2

0

2.01378

100.689

0.01012

0.502516

2

2

4.014699

100.3675

0.062759

1.563227

2

4

6.008268

100.1378

0.116569

1.940149

2

6

8.001837

100.023

0.081828

1.022609

 

 

 

 

Mean= 0.067819

Mean= 1.25712

 


Table no 2:C (bromocresol green)

Amount of Sample Added in (µg/ml)

Amount of Standard Added in (µg/ml)

Total amount recovered

Percentage recovery (%)

Standard deviation

Percentage of relative standard deviation (C.O.V.)

2

0

2.005042

100.2521

0.002964

0.147849

2

2

4.017367

100.4342

0.036638

0.91199

2

4

6.039216

100.6536

0.045282

0.749806

2

6

8.016807

100.2101

0.074603

0.930584

 

 

 

 

Mean= 0.039872

Mean= 0.68505

 


Results are in good in agreement with labelled value.

 

DISCUSSION:

The percent recovery obtained indicates noninterference from the common excipients used in the formulation. The reproducibility, repeatability and accuracy of these methods were found to be good, which is evidenced by low standard deviation. The proposed methods are simple, sensitive, accurate, precise and reproducible. They are directly applied to drug to form chromogen. Hence, they can be successfully applied for the routine estimation of Emtricitabine, in bulk and pharmaceutical dosage form even at very low concentration and determination of stability of drug in formulation such as tablets. The strong recommendation is made here for the proposed methods for determination of Emtricitabine from its formulation.

 

ACKNOWLEDGMENT:

Authors express sincere thanks to the Principal, D. G. Ruparel College, Mumbai.

 

REFERENCES:

1.        Dinesh Dhatkar, Sufiyan Ahmad, V. M. Shastry. Development and Validation of UV-Visible Spectrophotometric Method for Estimation of Emtricitabine and Tenofovir in Bulk and Dosage Form. International Journal of Pharmacy and Pharmaceutical Research. 2017; 9(3): 74-84

2.        Budagam Lavanya et.al. Method development and validation of combined dosage form of Emtricitabine and Tenofovir disproxil fumarate by ultra violet spectroscopy. International Research Journal of Pharmacy. 2012; 3(12):104-108.

3.        Anindita Behera, Aurobinda Parida1, Amit Kumar Meher, Dannana Gowri Sankar, Swapan Kumar Moitra, Sudam Chandra Si. Development and Validation of Spectrophotometric method for determination of Emtricitabine and Tenofovir disoproxil Fumarate in Bulk and Tablet dosage form. International Journal of PharmTech Research. 2011; 3(3): 1874-1882.

4.        Mohammad H. AbdelHay, Azza A. Gazy, Rasha A. Shaalan, and Heba K. Ashour. Simple Spectrophotometric Methods for Determination of Tenofovir Fumarate and Emtricitabine in Bulk Powder and in Tablets. Journal of Spectroscopy. 2013, Article ID 937409, 7 pages, http://dx.doi.org/10.1155/2013/937409.

5.        Rajan V. Rele, Prathamesh P. Tiwatane.  Derivative UV Spectrophotometric Method for Validation of Emtricitabine in Bulk and Pharmaceutical Dosage Form.  Asian J. Research Chem. 2020; 13(1): 48-51. DOI: 10.5958/0974-4150.2020.00011.5

6.        Rajan V. Rele. UV Spectrophotometric Estimation of Emtricitabine by Zero order and area under Curve methods in Bulk and Pharmaceutical Dosage Form. Asian J. Research Chem. 12(5); 2019:263-267. DOI: 10.5958/0974-4150.2019.00049. X.

7.        Rajan V. Rele Sandip Patil.  Development of Analytical Method by RP-HPLC Method for Validation of Emtricitabine in API and Pharmaceutical Dosage Form. Asian J. Research Chem. 2019; 12(3): 143-147. DOI: 10.5958/0974-4150.2019.00029.4

8.         Bhushan P. Badgujar, Moreshwar P. Mahajan, Sanjay D. Sawant. development and validation of RP-HPLC method for the simultaneous estimation of tenofovir alafenamide and emtricitabine in bulk and tablet dosage form, International Journal of Chem Tech Research. 2017; 10(5): 731-739.

9.        Arun Ramaswamy A, Anton Smith Arul Gnana Dhas. Development and validation of analytical method for quantitation of emtricitabine, tenofovir, efavirenz based on HPLC. Arabian Journal of Chemistry. 2018; 11: 275–281.

10.       Ajay D. Mali and Uttam B. More.  RP-HPLC method for simultaneous estimation of impurities from emtricitabine and tenofovir disoproxil fumarate tablet. International Journal of Pharmaceutical Sciences and Research. 2016; 7(4): 1662-1669.

11.      Mallikarjuna Rao Nagasarapu and Gowri Sankar Dannana. Development and validation of stability-indicating hplc-dad method for simultaneous determination of emtricitabine, elvetegravir, cobicistat and tenofovir in their tablet dosage forms. Indian Journal of Pharmaceutical Education and Research. 2016; 50(1): 205-211.

12.      Kalpana Jayapalu, Himaja Malipeddi, Anbarasu Chinnasamy. Chromatographic separation and in vitro dissolution assessment of tenofovir disoproxil fumarate, emtricitabine and nevirapine in a fixed dose combination of antiretrovirals. Journal of Applied Pharmaceutical Science. 2014; 4(11): 76-80.

13.      PSRCHNP Varma D and A Lakshmana Rao. Stability-Indicating RP-HPLC method for the simultaneous estimation of efavirenz, tenofovir and emtricitabine in pharmaceutical formulations. Indian Journal of Pharmacy and Pharmacology. 2014; 1(1): 1-17.

14.      Bala Rami Reddy. Yenumula, Mutta Reddy. Singampalli and Bala Sekhara Reddy. Challa, Simultaneous estimation of emtricitabine and tenofovir disoproxil fumarate in tablet dosage form by reverse phase high-performance liquid chromatography. International Journal of Analytical Techniques. SOJ Chromatograph Sci. 2015; 1(1): 62-6.

15.      Prashant S. Devrukhakar, Roshan Borkar, Nalini Shastri, and K. V. Surendranath. A Validated stability-indicating RP-HPLC method for the simultaneous determination of tenofovir, emtricitabine, and a efavirenz and statistical approach to determine the effect of variables. ISRN Chromatography. 2013, Article ID 878295, 8 pages, http://dx.doi.org/10.1155/2013/878295.

16.      Akram, M. Umamahesh N. A new validated RP-HPLC method for the determination of emtricitabine and tenofovir af in its bulk and pharmaceutical dosage forms. Journal of Chemical and Pharmaceutical Sciences. 2017; 10(4): 54-59.

17.      Srinivasa Rao A, Naveen Kumar G, Srilekha K, Aruna Kumari N. Stability indicating method for the simultaneous estimation of tenofovir, emtricitabine and efavirenz in pure and pharmaceutical dosage form by RP-HPLC. 2016; 5(5):188-200.

18.      Umesh Maniyar, M. V. Katariya, Kishor Kumar Koshe, Gopal Karva, Sushil Jaiswal. Stability indicating RP-HPLC method for the simultaneous estimation of efavirenz, emtricitabine and tenofovir disoproxil fumarate in combined pharmaceutical dosage form. World Journal of Pharmacy and Pharmaceutical Sciences. 2016; 5(6): 1180-1198.

19.      SK Mastanamma, D Venkata Reddy, P Saidulu and M Varalakhimi. Development and validation of stability indicating RP-HPLC method for the simultaneous estimation of emtricitabine tenofovir alafenamide bulk and their combined dosage form. Journal of Chemical and Pharmaceutical Research. 2017; 9(9): 70-80.

20.      Som Shankar Dubey and Mahesh Duggirala. High performance liquid chromatography with PDA detector for combined determination of emtricitabine, tenofovir and efavirenz. Der Pharmacia Lettre. 2015; 7(10):85-91.

21.      P.D. Hamarapurkar, Abhijeet N. Parate. HPLC method for the determination of emtricitabine and related degradation substances. Journal of Chromatographic Science. https://academic.oup.com/chromsci/article/51/5/419/326539.

22.      Abdul Sattar and Suneetha Achanta. Analytical Method Development and validation for the determination of emtricitabine and tenofovir disoproxil fumarate using reverse phase hplc method in bulk and tablet dosage form. Journal of Pharmaceutical Science and Research. 2018; 10(5): 1207-1212.

23.      J. Saminathan and T. Vetrichelvan. Development and validation of HPTLC method for simultaneous estimation of emtricitabine, rilpivirine and tenofovir disoproxil fumarate in combined dosage form. Bangladesh Pharmaceutical Journal. 2016; 19(1): 114-121.

24.      Mahesh S. Wajurkar, Manjusha N. Dole, development and validation of HPTLC method for determination of emtricitabine in API and tablet dosage form. Journal of Advanced Scientific Research. 2015; 6(3): 51-54.

 

 

Received on 22.12.2024      Revised on 21.01.2025

Accepted on 15.02.2025      Published on 14.04.2025

Available online from April 18, 2025

Asian J. Research Chem.2025; 18(2):77-80.

DOI: 10.52711/0974-4150.2025.00012

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