Stability Indicating HPTLC Method for Estimation of Metoprolol Tartrate in Bulk and in Pharmaceutical Formulation

 

Shailesh Dadge1, Chaitali Dhale1, Savita Yadav2, Janhavi Rao2*

1Department of Quality Assurance Techniques, Bharati Vidyapeeth University, Poona College of Pharmacy, Erandwane, Pune-411038, India.

2Department of Pharmaceutical Chemistry, Bharati Vidyapeeth University, Poona College of Pharmacy, Erandwane, Pune-411038, India.

*Corresponding Author E-mail: raojanhavi@rediffmail.com

 

ABSTRACT:

In the present study a rapid specific economical HPTLC method has been developed for determination of Metoprolol tartrate in bulk and pharmaceutical dosage form. Chromatographic separation was achieved on aluminium plates precoated with silica gel 60 F254 aluminium plates with mobile phase of chloroform: methanol: ammonia 9: 1: 0.05 (v/v/v). Detection was performed densitometrically at 225 nm using Camag TLC scanner. The Rfof Metoprolol tartrate found to be 0.26±0.02 and linearity was found in the concentration range of 200-1200 ng/spot with correlation coefficient (R2) of 0.998. The method was validated as per ICH guidelines for precision, recovery and robustness. Metoprolol was subjected to acid and alkaline hydrolysis, oxidation, photochemical and thermal degradation as per ICH guidelines. Method developed was stability indicating. Statistical analysis proves that the method is suitable for the analysis of Metoprolol tartrate in bulk drug and in pharmaceutical formulations without any interference from the excipients.

 

KEYWORDS: Metoprolol tartrate, Thin layer chromatography, Stability indicating, Degradation, Validation, ICH guidelines.

 

 


INTRODUCTION:

Metoprolol tartrate1, 2, bis [(2RS)-1-[4-(2-methoxyethyl) phenoxy]-3-[(1-methylethyl) amino] propan-2- ol] (R, 3R)-2, 3-dihydroxybutanedioate is a Beta-1-adrenoreceptor blocking agent. It competitively blocks β1-adrenergic receptors in the heart and glomerular apparatus. They lead to decreased heart rate decreasing the work load by the heart. It acts on the central nervous system to reduce sympathetic outflow and vasoconstrictor tone. It is very soluble in water; freely soluble in methylene chloride, in chloroform, and in alcohol; slightly soluble in acetone; and insoluble in ether.

 

 

It has many indications such as hypertension, angina pectoris, cardiac arrhythmias, definite or suspected acute myocardial infarction, and migraine prophylaxis, adjunctive management of hyperthyroidism and adjunctive management of thyrotoxicosis1-2. Few methods have been reported for Metoprolol tartrate in pharmaceuticals. Metoprolol tartrate has been determined using HPLC, Spectrophotometric and Hyphenated method such as HPLC MS3-13. The reported methods have few drawbacks such as repeatability and reproducibility, overall cost of analysis of reported chromatographic method is more. However there is no validated High Performance Thin Layer Chromatography (HPTLC) method reported for the determination of Metoprolol Tartrate. The International Conference on Harmonization (ICH) guideline entitled ‘stability testing of new drug substances and products’ requires the stress testing to be carried out to elucidate the inherent stability of characteristics of the active substances. The aim of the present work is to develop an accurate, specific, and reproducible stability indicating HPTLC method for determination of Metoprolol tartrate in presence of degradation products formed under different stress conditions.

 

 

Fig 1. Chemical Structure of Metoprolol Tartrate.

 

MATERIALS AND METHODS:

Metoprolol tartrate standard was procured from procured from Ajanta Pharmaceuticals, Mumbai (India). As gift sample. Tablets containing Metoprolol tartrate 50mg was procured from local market (Betaloc). Silica Gel plates were purchased from E Merck India Pvt. Ltd. Mumbai. AR grade of solvents used for this study were purchased from Merck Pvt. Ltd, Mumbai.

 

Instrumentation:

Camag HPTLC System (with TLC Scanner, Win CATS Software Version 4.0 and Linomat 5application device) used for the analysis. Precoated silica gel 60 F254 on aluminum sheets (200μm thick) of E-Merck, Germany were used as stationary phase. Pre-washing of plate wasdone with methanol and then it was activated by keeping in an oven at 1150C for 10 minutes. The samples were spotted in the form of bands of width 6 mm with a Camag 100 μl sample(Hamilton Bonded, Switzerland) syringe. A constant application rate of 0.1 μl/s was usedand the space between two bands was 5 mm. The slit dimension was kept at 5 mm × 0.45 mmand the scanning speed was 10 mm/s. Linear ascending development was carried out in a 20cm × 10 cm twin trough glass chamber (Camag, Muttenz, Switzerland) saturated with themobile phase. Each chromatogram was developed over a distance of 8 cm. The source of radiation used was deuterium lamp emitting a continuous UV spectrum between 190 and 400nm.

 

Preparation of standard solution:

Accurately weighed quantity 25 mg of Metoprolol tartrate was transferred to 25.0 ml volumetric flask and diluted up to the mark with the methanol to get the concentration of 1000μg/ml. This solution was used as standard stock solution. 10 ml of the standard stock solution was diluted with 100 ml of methanol to get the concentration of the 100μg/ml used as working standard solution.   

 

Detection of Suitable wavelength:

In order to determine the absorbance maxima (λmax), working standard solution of Metoprolol tartrate in methanol was spotted on the plate and scanned by CAMAG TLC scanner in the range of 200-400 nm. The spectra Metoprolol Tartrate was recorded, the wavelength 225 were selected for determination for evaluation, since the drug shows the maximum wavelength of absorption of 225nm (Fig: 2).

 

Optimization of the HPTLC Method:

The TLC procedure was optimized with a view to develop a validated assay method forMetoprolol tartrate in bulk and dosage form. The drug solution was spotted on to precoated TLC plates and run in different solvent systems. Finally the mobile phase consisting of Chloroform: Methanol: Ammonia (9: 1: 0.05, v/v/v) was found to be optimum, resulting in Rf of 0.26 ± 0.02 at detection wavelength 225 nm. The mobile phase was run up to a distance of 8 cm which takes approximately 15 min for complete development of the TLC plate.

 

METHOD VALIDATION:

Validation of the optimized HPTLC method was carried out with respect to Linearity & Range, Precision, Limit of detection (LOD) & Limit of Quantitation (LOQ) and Accuracy according to ICH Q2 (R1) guidelines14-25.

 

Stability of solute during Plate development:         

The decomposition of the analyte during spotting or development was confirmed by the two dimensional chromatography using the optimized mobile phase in both directions. The standard Metoprolol tartrate of strength 160ng/spot from the working standard solution determines the stability.

 

In situ stability after TLC development:

The standard solution of Metoprolol tartrate of concentrations of 200 to 1200ng/band from the working standard solution was applied to the HPTLC plates. After development the Plates were scanned and was stored in dark and rescanned after 24 Hours in the same detection wavelength and the peak areas were matched.

 

Linearity:

Linearity was determined by constructing calibration curves at five concentration levels. Aliquots of working standard solution of Metoprolol tartrate was applied on to the plate, to obtain concentration in the range 200 to 1200 ng/spot. The calibration curves were developed by plotting peak area vs. concentration with the help of Win- CATS software. After completion of scanning, peak areas were noted. Peak area was plotted against corresponding concentrations and least square regression analysis was performed to generate

the calibration equation.   

Limit of Detection (LOD) and Limit of Quantification (LOQ):

LOD and LOQ was determined by using visual inspection method, by injecting the lowest amount of the working standard solutions, Spotting was done by taking different concentrations from working standard solution as 10, 20, 30, 40 ng/spot applied on to the plate by using Auto sampler. By the visual inspection method the peaks were identified.

 

Robustness of the method:

Robustness studies were done making small, deliberate changes in the optimized conditions like Mobile phase composition ±2%, Saturation time, Development distance by applying concentration 400 ng/spot from the working standard solution and the results were examined. The % RSD of peak areas was calculated for each parameter.

 

Specificity:

The specificity of the method was ascertained by analyzing standard drug and the sample. The spot was confirmed by comparing the Rf and the spectra of the spot with those of the standard by applying the working standard solution and the prepared marketed sample of 1000 μg/ml. The peak purity of the sample was assessed by comparing the spectra at the peak start, peak apex and peak end position of the spot.

 

Accuracy:

Accuracy of the method was determined by applying the method to drug sample (Metoprolol tartrate) to which known amount of Metoprolol tartrate standard drug corresponding to 80%, 100% and 120% of label claim has been added. The recovery was carried out by Standard addition method, sample equivalent to (160 ng/band) was selected, To the solution 80%, 100% and 120% of the standard drug solutions were added at (80, 100, 120 ng/band) from the working standard solution.

 

Assay:

The possibility of excipients interference with the analysis was examined by carrying out theassay. A strip of twenty tablets of Metoprolol tartrate (Betaloc-50 mg) was taken and each tablet of Metoprolol tartrate was weighed and average weight was noted down. The tablets were crushed as fine powder by using motor and pestle. Powdered drug equivalent to the average weight of 50mg was weighed and dissolved in 25ml of methanol, and ultrasonicated for about 15 minutes with swirling. After sonication, the volume was made up to the mark with methanol, and mixed well. The solution was filtered through 0.45μ filter paper. From the resultant solution 10ml was taken and made up to 100ml with methanol, from the finally obtained solution, 1.5 ml was taken and made up to 10ml with the mobile phase which results to solution of 1.5μg/ml, The finally obtained solution was analyzed by the proposed method and compared with the standard. The amount of Metoprolol in the tablets was calculated by suitably applying the dilution factor. The possibility of excipients interference with the analysis was examined.

 

Forced Degradation Studies:

Force Degradation on the drug was carried out by following the ICH Guidelines. Metoprolol tartrate was degraded under different stress conditions like acidic hydrolysis, alkaline hydrolysis, oxidative and hydrolytic degradation.

 

Acid induced degradation study:

The studies in Acid conditions were carried out in 0.1 N Hydrochloric Acid and the solutions were refluxed for 2 hours at 60°C. The resultant solutions were applied on TLC plate.

 

Base induced degradation study:

The studies in Acid conditions were carried out in 0.1 N Sodium Hydroxide and the solutions were refluxed for 3 hours at 60°C. The resultant solutions were applied on TLC plate in such a way that final concentration achieved was 400 ng/spot and the chromatograms were run.

 

Hydrogen peroxide induced degradation study:

To 10 ml of the stock solution, 10 ml of 3%, 10%, 30% hydrogen peroxide was added separately and the solution was refluxed for 0,2,4,6 hours, for the HPTLC Study, the resultant solution was diluted to obtain 400µg/ml solution and applied onto the plates and chromatograms were recorded to assess the stability of the sample.

 

Photochemical degradation study:

To study photochemical degradation Metoprolol tartrate was exposed in dry as well as in wet form to sunlight for 2 hrs. The resultant solutions were applied on TLC plate in such a way that final concentration achieved was 400 ng/spot and the chromatograms were run.

 

Neutral Degradation study:

To study neutral degradation, the drug was refluxed for 0, 1, 2, 3, 4, 5, 6 hours at 60°C. The resultant solutions were applied on TLC plate in such a way that final concentration achieved was 400 ng/spot and the chromatograms were run.

 

Thermal Degradation study:

The dry heat study of a drug was studied by keeping the drug in a hot air oven at 30°C, 40°C, 50°C, and 60°C. and withdraw sample at various time intervals 30min, 2hrs, 3hrs, 4hrs, and 5 hrs. The resultant solution was diluted to obtain 400ng/spot solution and check for the degradant, and applied on the TLC plates.

 

RESULTS AND DISCUSSION:

Validation:

The optimized HPTLC method was validated as per ICH guidelines Q2 (R1) with respect to the following parameters.

 

Stability:

Stability of solute during plate development:

The standard Metoprolol tartrate of strength 160ng/spot from the working standard solution when employed for stability studies did not show any extra peak which determinedthe stability of solute during plate development.

 

In situ stability after TLC development:

The standard solution of Metoprolol tartrate of concentrations of 200 to 1200ng/band was applied to the HPTLC plates. After development the plates were scanned and was stored in dark and rescanned after 24 Hours, did not show any difference in peak shape, peak heightand area.

 

Linearity:

The linearity was determined by injecting the different concentrations over the range 200-1200 ng/spot of the working standard solutions on the precoated HPTLC plates. Each concentration was applied six times to the plate and the plate was developed as described above. The plates were scanned at 225 nm and the spectrum were recorded (Fig 2). Peak areas were plotted against corresponding concentration to get the calibration plot. (Fig 3). Regression equation and correlation coefficient were obtained (Table 1). The Rf value was found to be 0.26(Fig 5). The linear regression data for the calibration curves (n=6) showed good linear relationship over the concentration range of 200-1200 ng/spot for Metoprolol tartrate (correlation co-efficient, r=0.998), the data was subjected to regression analysis. The linearity and residual plots were given in (Fig 3) and (Fig 4).

 

LOD and LOQ:

The limit of detection and quantification with the visual inspection method was found to be 60ng/spot as LOD and 200 ng/spot as LOQ. It was concluded that the developed method was sensitive. (Table 2).

 

Precision:

The precision of the method was verified by repeatability and intermediate precision studies. Repeatability studies were performed by spotting three different concentrations of Metoprolol Tartrate 400, 600, 800ng/spot respectively for three times on the same day. The Interday precision of the method was checked by repeating studies on three different days. The developed method was found to be precise given in the (Table 3 and 4).

 

Repeatability:

Repeatability of the method was checked by analyzing a standard solution of Metoprolol Tartrate after application of 400ng/spot from the standard solution on TLC plate (n=6) and RSD was found to be 0.82%.

 

Robustness

Robustness studies were done making small, deliberate changes in the optimized conditions like Mobile phase composition ±2%, Saturation time, Development distance, by applying to the concentration 400 ng/spot from the working standard solution and the % RSD was found to be less than 2%. (Table 5).

 

Specificity:

The method is termed to be specific for Metoprolol Tartrate, since it resolved the peak of Metoprolol Tartrate (Rf 0.26) in presence of other excipients in the formulation. The developed method was also confirmed by overlaying the spectra of standard Metoprolol Tartrate and the sample solution applied.

 

Accuracy:

The accuracy studies for the Metoprolol tartrate were carried out by standard addition method, in the standard drugs were added to pre-analyzed tablet sample at three different levels namely 80,100,120%, total amount of the drug was determined by the proposed method. The percentage recovery was calculated and found to be 99.6 to101.7% with the mean % RSD in acceptable range. The low percentage RSD indicated the suitability of the method for the routine analysis of the Metoprolol tartrate in pharmaceutical dosage form. (Table 6).

 

Assay:

A single spot of Rf of 0.26 was observed in the chromatogram of the drug sample extracted from convention tablets. There is no interference from the excipients commonly present in the conventional tablets. The drug content was found to be 100.6%±5.8 with the mean % RSD of 0.55. The low percentage RSD indicated the suitability of the method for the routine analysis of the Metoprolol Tartrate in pharmaceutical dosage form.

 

Forced Degradation Studies:

Stress testing under Acidic condition:

Acid degradation product, Metoprolol tartrate refluxed with 0.1N HCl at 60°C for 2 hrs showing 12.79 and 7.53% degradation with additional peaks at Rf 0.40 and Rf 0.67. (Fig 6).

 

 

Stress under Basic conditions:

The reaction in 0.1 N sodium hydroxide was used at 60 °C for 3 hrs of base degradation product of Metoprolol tartrate showing 10.51% degradation with additional peaks at Rf 0.58. (Fig 7).

 

Oxidative degradation:

Oxidative degradation of Metoprolol tartrate was refluxed with 3 % H2O2 for 3 hrs at 80°C showing 13.19 % degradation with additional peaks at Rf 0.36, 0.46. (Fig 8).

 

Photolytic degradation (Dry and Wet form):

Metoprolol tartrate was found to be unstable to photochemical degradation. It was found that after exposing drug in dry as well as in wet form to sunlight for 2 hrs showing 7.2% and 8.3% degradation for dry and wet form, with additional peaks at Rf 0.46 for both dry and wet form as shown in (Fig 9 and 10).

 

Neutral degradation:

Neutral degradation of Metoprolol tartrate was performed by refluxing with water for 1hrs at 60°C showing 20.13% degradation with additional peak at Rf 0.62 (Fig 11).

 

Thermal Degradation:

Metoprolol tartrate was subjected to thermal degradation at 60°C for 5 hrs. The result of thermal degradation was found to be 11.06% with additional peak at Rf 0.68. (Fig 12).

 

Fig 2. UV Spectrum of Metoprolol tartrate

 

Fig 3. Linearity Graph of Metoprolol tartrate

 

Fig 4. Residual plot of Metoprolol tartrate

 

 

Fig 5. HPTLC chromatogram of Metoprolol tartrate

 

 

Fig 6. Acid hydrolysis of Metoprolol tartrate

 

 

Fig 7. Base hydrolysis of Metoprolol tartrate

 

Fig 8. Oxidative degradation of Metoprolol tartrate

 

Fig 9. Photolytic degradation of Metoprolol tartrate (Dry powder)

 

Fig 10. Photolytic degradation of Metoprolol tartrate (Wet form)

 

Fig 11. Neutral Degradation of Metoprolol tartrate

 

Fig 12. Thermal Degradation of Metoprolol tartrate

 

Table 1. Linearity studies

Parameters

Ranges

Linearity range (ng/spot)

200-1200

r2

0.998

Slope

261.7

Intercept

56.69

 

Table 2. LOD and LOQ

Sample

LOD

LOQ

Metoprolol tartrate

60 ng/spot

200 ng/spot

 

Table 3. Interday precision of Metoprolol tartrate

Concentration (ng/spot)

Area

Avg

St dev

%RSD

 

400

6890.1

6865.16

20.37

0.29

6865.2

6840.2

 

600

8691.3

8536.53

109.15

1.28

8461.9

8456.4

 

800

11445.7

11335.77

117.98

1.04

11389.5

11172.1

 

Table 4. Intraday precision details of Metoprolol tartrate

Concentration (ng/spot)

Area

Avg

Std dev

%RSD

400

1278.1

1276.6

8.35

0.65

1286

1265.7

600

1659.8

1661.36

7.39

0.44

1653.2

1671.1

800

2234.6

2255.16

19.03

0.84

2280.5

2250.4

 

Table 5. Robustness studies of Metoprolol tartrate

Condition

Rf

Peak area

%RSD

Mobile phase composition (±0.1 for chloroform and for ammonia ± 0.01 v/v/v )

Chloroform: Methanol : Ammonia (8.9:1:0.04)

0.29

959.9

0.08

Chloroform: Methanol: Ammonia (9:1:0.05)

0.26

954.8

0.27

Chloroform: Methanol: Ammonia (9.1:1.1:0.06)

0.28

958.7

0.67

Development distance (±0.5 cm)

 

7.5

0.24

952.1

0.99

8

0.29

957.8

0.80

8.5

0.24

954.2

0.71

Duration of Saturation (± 5 mins)

20 min

0.28

957.8

0.21

25 min

0.23

959.9

0.45

30min

0.27

960.0

0.75

 

Table 6. Recovery details of Metoprolol tartrate

Label claim

%

Level

Total amount added (mg)

Concentration of drug found

(ng/spot)

% Recovery

% RSD

Metoprolol tartrate 50 mg

80

90

89.53

99.48

1.42

100

100

99.6

99.6

0.45

120

110

107.97

98.16

0.71

 

CONCLUSION:

HPTLC method has been developed for estimation of Metoprolol tartrate in bulk and in tablet formulation. The separation was achieved using silica gel pre-coated aluminium plate 60 F254(10×10 cm) with 250 μm thickness as a stationary phase and using Chloroform: Methanol: Ammonia (9:1:0.05) as a mobile phase at Rf 0.26.

 

The developed method was validated for various parameters as per ICH guidelines for repeatability, linearity, precision, accuracy, and specificity.

 

The Calibration curve was plotted of Metoprolol tartrate area v/s Concentration. The generated regression equation was y=261.7x-56.79 and coefficient of correlation R2=0.998 which that developed method is linear in the range of 200-1200 ng/spot.

 

The proposed method was precise as % R.S.D values for intraday and interday precision were found to be less than 2%. For recovery study, drug for 80%, 100% and 120% level concentration showed 99.9%, 100.66% and 99.04% good recoveries. Hence, it can be supposed that this method was accurate. The LOD and LOQ were calculated as 60 ng/µl and 200 ng/µl respectively.

 

The drug content recovered from assay was found to be 99.6% which is satisfactory with a percentage a %RSD of 0.45.

 

Forced Degradation studies on the drug were carried out by following the ICH Guidelines. The drug was found to be degraded in acid, base, oxidative, photochemical, wet and thermal condition. The degradant peak is well resolved from the drug peak.

 

Statistical analysis proves that the method is suitable for the analysis of Metoprolol in bulk and pharmaceutical formulations without any interference from the excipients. The method was validated as per ICH guidelines. The developed validated HPTLC method may be extended to study the degradation kinetics and also for its estimation in plasma and other biological fluids. The result shows that the method could find practical application as a quality control tool for estimation of Metoprolol tartrate.

 

ACKNOWLEDGEMENT:

The authors are thankful to Bharati Vidyapeeth University’s Poona college of Pharmacy, Pune (M.S), India, for providing necessary facilities. The authors are also thankful to Ajanta Pharmaceuticals, Mumbai (India), for providing the gift sample of standard drug.

 

REFERNCES:

1.     Philip A Poole-Wilson, MD, Prof Karl Swedberg, MD, John GF Cleland, MD, Comparison of carvedilol and metoprolol on clinical outcomes in patients with chronic heart failure in the Carvedilol Or Metoprolol European Trial (COMET): Randomised Controlled Trial, Chest, 2003, Pg no,7-13.

2.     Beni Rai Verma, Sunjeet Kaur, Sarah Knorr, Beta blocker therapy is safe and associated with low mortality in patient with high grade atrioventricular block during ST segment elevation myocardial infarction, Journal of the American College of Cardiology Foundation, 2016, 561-568

3.     Mustafa Cesme, Derya Tarinc and Aysegul Golcu, Spectrophotometric Determination of Metoprolol Tartrate in Pharmaceutical Dosage Forms on Complex Formation with Cu(II), Pharmaceuticals, 2011, Vol.4, Issue No.7; 964-975.

4.     Nafisur Rahman, SK Manirul Haque and Syed Najmul Hejaz Azmi, Kinetic Spectrophotometric Determination of Metoprolol Tartrate in Commercial Dosage Forms, Journal of the Chinese Chemical Society, 2007, Issue No.7; 1511-1520.

5.     Mohamed I Walash, Fathallah F Belal, Nahed M El-Enany and Mahmoud H El-Maghrabey, Synchronous fluorescence spectrofluorimetric method for the simultaneous determination of metoprolol and felodipine in combined pharmaceutical preparation, Chemistry Central Journal, 2011, 1-9.

6.     Bilal Yilmaz, Kadem Meral, Ali Asci, Yavuz Organer, Determination of Metoprolol in Pure and Pharmaceutical dosage forms by spectroflurimetry and High Performance Liquid Chromatography, Chemical Industry & Chemical Engineering Quarterly, 2011, Vol.17, Issue No.1; 25-31.

7.     Sohan S Chitlange, Mohammed Imran, Dinesh M Sakarkar, RP-HPLC method for simultaneous estimation of amlodipine and metoprolol in tablet formulation, Asian Journal of Pharmaceutics, 2008, Vol.3, Issue No.1; 232-234.

8.     Janhavi R Rao, HPTLC Method Development and Validation for Simultaneous Estimation of Metoprolol Succinate and Felodipine In Bulk Drugs and Combined Dosage Forms, International Journal of Pharma and Bio Sciences, 2018 April Vol.9(2) 1 – 7

9.     Lakshmi Madhuri B, Savita Yadav and Janhavi Rao, Method development and validation of Bosentan in bulk and pharmaceutical formulation by using HPTLC, World Journal of Pharmacy and Pharmaceutical Sciences, 2016, Vol.5, Issue No.4; 1394-1405.

10.   Ranjit Singh, Zia Ur Rehman, Current trends in forced degradation study for pharmaceutical product development. J Pharm Educ Res 2012 Vol. 3, Issue No. 1.Pg no 14-18.

11.   M.S. Charde, Jitendra Kumar, A. S. Welankiwar and R. D Chakole, Review: Development of forced degradation studies of drugs. International Journal of Advances in Pharmaceutics, 2013, Vol 2, Issue No.3; pg no-34-39

12.   Mahaboob Basha D, G. Venkata Reddy, Sobha Rani, et al, A review on forced degradation studies and its importance in analytical method development and validation, International Journal of Innovative Pharmaceutical Sciences and Research, 2014, Issue No-2929-2940; 2347-2154.

13.   Blessy M, Ruchi D. Patel, Prajesh N Prajapti, Prajesh N Prajapti, Y.K. Agrawal, Development of forced degradation and stability indicating studies of drug- A Review. Journal of Pharmaceutical Analysis. 2014, Vol-4, Issue 3; 159–165.

14.   S.M. Khopkar, Basic Concepts of Analytical Chemistry, New Age International Ltd. Publishers, New Delhi, 1998, 2nd edition; 178-179.

15.   F. Settle, Handbook of Instrumental techniques for analytical chemistry, Prentice Hall PTR, NJ, 1997, 17-19, 56-57,

16.   Skoog, D.; Holler, F.; Crouch, S. Principles of Instrumental Analysis 2009: 44-50

17.   J. Mendham, R.C. Denney, J.D. Barnes, M. Thomas, Vogel’s Textbook of Quantitative Analysis. Pearson Education, Singapore, 2003, 8-9.

18.   B.K. Sharma, Instrumental Methods of Chemical Analysis, Goel Publication Co., Meerut, 1983, 25th edition, 3, 6.

19.   G.R. Chatwal, S.K. Anand, Instrumental Methods of Chemical Analysis, 5th edition, Himalaya Publishing House, Mumbai, pp. 1.1-1.5, 2.108-2.109, 2.60.

20.   E. Stahl. Thin Layer Chromatography A Laboratory Handbook, 2nd edition, Springer, India, 2006, pp. 52-66.

21.   P.D. Sethi, HPTLC Quantitative Analysis of Pharmaceutical Formulations, 1st Edition. CBS Publishers and Distributors, Mumbai, 2001, pp. 3-21, 38, 359-360

22.   A.H. Beckett, J.B. Stenlake, Practical Pharmaceutical Chemistry, CBS Publishers and Distributors, New Delhi, Part-2, 2002, pp. 275-288.

23.   ICH, Q2 (R1), Validation of Analytical Procedures: Text and Methodology. International Conference on Harmonization, Geneva, 2005, pp. 1- 13.

24.   ICH, Q2A, Text on Validation of Analytical Procedures. International Conference on Harmonization, Geneva, October 1994, pp. 1-5.

25.   ICH, Q2B, Validation of Analytical Procedures: Methodology. International Conference on Harmonization, Geneva, November, 1996, pp. 1-8.

 

 

 

Received on 29.05.2018         Modified on 20.06.2018

Accepted on 29.06.2018         © AJRC All right reserved

Asian J. Research Chem. 2018; 11(4):755-762.

DOI: 10.5958/0974-4150.2018.00133.5