NANODROP SPECTROPHOTOMETRIC METHOD DEVELOPMENT AND VALIDATION FOR ESTIMATION OF RANOLAZINE IN THEIR BULK

NANODROP SPECTROPHOTOMETRIC METHOD DEVELOPMENT AND VALIDATION FOR ESTIMATION OF RANOLAZINE IN THEIR BULK

Rakesh Kumar Singh*¹, Pankaj Singh Patel ¹, Paras Malik ² and Tej Pratap Singh ²

KNGD Modi Institute of Pharmaceutical Education and Research, Modinagar, Uttar Pradesh, India

Venkateshwara School of Pharmacy, Meerut, Uttar Pradesh, India

ABSTRACT

Nanodrop spectrophotometric method was developed and validated for the estimation of Ranolazine in bulk. Ranolazine exhibited λ_max at 272nm in water and obeyed linearity in the concentration range of 12.5-2000 ppm. The proposed method has been applied successfully for the analysis of Ranolazine in bulk with good accuracy and precision. The method herein described can be employed for quality control and routine analysis of Ranolazine in bulk.

Bulk

INTRODUCTION: The scope of developing and validating analytical methods is to ensure a suitable method for a particular analyte more specific, accurate and precise. The main objective for that is to improve the conditions and parameters, which should be followed in the development and validation.

Ranolazine a partial fatty acid oxidation inhibitor, a new class of anti-anginal drugs, which inhibit fatty acid beta-oxidation and activate pyruvate dehydrogenase, thereby diverting the heart's energy source from lipids to glucose, which requires less oxygen and helps maintain myocardiac function at times of ischemia ¹. Ranolazine is indicated for the treatment of chronic angina. Ranolazine may be used with beta-blockers, nitrates, calcium channel blockers, anti-platelet therapy, lipid-lowering therapy, ACE inhibitors, and angiotensin receptor blockers.

(±) - 4- [2- HYDROXY- 3- (O- METHOXYPHENOXY) PROPYL] - 1-PIPERAZINEACETO-2′, 6′- XYLIDIDE DIHYDROCHLORIDE, N-(2, 6- DIMETHYLPHENYL) - 4- [2- HYDROXY- 3- (2-METHOXYPHENOXY) PROPYL] - 1- PIPERAZINEACETAMIDE

Ranolazine is available as a film-coated, non-scored, extended-release tablet for oral administration. Ranolazine is a white to off-white solid. Ranolazine is soluble in dichloromethane and methanol; sparingly soluble in tetrahydrofuran, ethanol, acetonitrile, and acetone; slightly soluble in ethyl acetate, isopropanol, toluene, and ethyl ether; and very slightly soluble in water. Literature survey revealed that various analytical methods such as HPLC ², LC-MS ^{3, 4, 6, 7, 8} are used for assay of ranolazine in bulk and pharmaceutical dosage form and for bioequivalence study. No Nanodrop spectrophotometric method has been reported for estimation of Ranolazine in bulk. Hence, an attempt has been made to develop new Nanodrop Spectrophotometry method for its estimation in bulk with good accuracy, simplicity, precision and economy. The Nanodrop ND-1000 is a full-spectrum spectrophotometer (UV and visible spectrum, 220-750 nm) for measuring the absorbance the sample droplet is held in place by surface tension when it is slightly compressed between the pedestal and the sample arm; this generates the defined pathway of 1 mm.

The spectrum measurement is then performed with two optical fibers installed in the pedestal (emitting light of a Xenon lamp) and the sample arm (spectrometer with linear CCD array). Quantification is performed based on the spectrum measurement at the defined pathway of 1 mm. Unlike traditional spectrophotometers, the Nanodrop does not require cuvettes or capillaries. Instead, the sample is pipette directly onto the measurement pedestal.

EXPERIMENTAL:

Instrumentation: Spectral and absorbance measurements were made on Nanodrop spectrophotometer. Denver TB-215D balance was used for weighing the samples.

Chemical: Ranolazine dihydrochloride, Ajanta Pharma, Mumbai; Distilled water

Apparatus/Instruments:    

Optimization:

Scanning and determination of maximum wavelength (l_max): In order to ascertain the wavelength of maximum absorption (λ_max) of the drug, different solutions of the drug (200 ppm and 400 ppm) in distilled water were scanned using Nanodrop spectrophotometer within the wavelength region of 220- 700nm against distilled water as blank. The resulting spectra are shown in fig. A, B, C and the absorption curve showed characteristic absorption maxima at 272nm for Ranolazine. All spectra of analysis are shown in fig. D.

METHODS:

Preparation of standard stock solution: Standard stock solution was prepared by dissolving 20 mg equivalent Ranolazine in 10 ml of distilled water to get concentration of 2 mg/ml (2000 ppm) solution.

Preparation of working standard solutions and construction of standard graph: The prepared stock solution was further diluted with distilled water to get working standard solutions of 12.5, 25, 50, 100, 200, 400, 800, 1000, 1200, 1600, 1800 and 2000 ppm of Ranolazine to construct Beer’s law plot for pure drug, the absorbance was measured at λ _max 272 nm, against distilled water as blank. The results are shown in table 1. The standard graph was plotted by taking concentration of drug on X-axis and absorbance on Y-axis and is shown in fig. E. The drug has obeyed Beer’s law in the concentration range of 12.5-2000 ppm. The linearity curve data is shown in table 2. All spectra for linearity are shown in fig. F.

TABLE 1: LINEARITY TABLE OF RANOLAZINE IN WORKING STANDARD

FIG. E: LINEARITY CURVE OF RANOLAZINE

TABLE 2: LINEARITY CURVE DATA

* y=mx+c where ‘x’ is the concentration of Ranolazine in ppm and y is the absorbance

Spectra of Linearity:

FIG. F: ALL SPECTRA FOR LINEARITY

Validation:

Accuracy: To determine the accuracy of the proposed method, recovery studies were carried out by adding different amounts (80%, 100%, and 120%) of bulk samples of Ranolazine within the linearity range were taken. From that percentage recovery, values were calculated. The results are shown in table 3. All spectra for accuracy are shown in fig. G.

TABLE 3: ACCURACY READINGS

% Recovery= amount recovered / amount introduced X 100

Spectra of accuracy:

FIG (G) ALL SPECTRA FOR ACCURACY

Precision: The precision of the proposed method was ascertained by actual determination of six replicates of fixed concentration of the drug within the Beer’s range and finding out the absorbance by the proposed method. From this absorbance, mean, standard deviation and % RSD was calculated. The system precision and method precision readings are shown in table 4A and 4B respectively. Spectra for system precision and method precision are shown in fig. H and I respectively.

  TABLE 4 A: SYSTEM PRECISION READINGS

 TABLE 4 (B): METHOD PRECISION READINGS

Spectra of system precision:

FIG H: SPECTRA FOR SYSTEM PRECISION

Spectra of method precision:

FIG. I: SPECTRA FOR METHOD PRECISION

 RESULTS AND DISCUSSION: From the optical characteristics of the proposed method, it was found that Ranolazine obeys linearity within the concentration range of 12.5-2000 ppm. From the results shown in accuracy table (3), it was found that the percentage recovery values were in between 92.18-96.17, which indicates that the proposed method is accurate. From the results shown in table 4 (a) and 4 (b) it was found that the % RSD is less than 2, which indicates that the system and method have good reproducibility.

CONCLUSION: The proposed method was simple, sensitive and reliable with good accuracy and precision. Hence, this method can be used for the routine determination of Ranolazine in bulk form.

ACKNOWLEDGEMENTS: The authors thank Ajanta Pharma, Mumbai for providing the gift sample of Ranolazine.

REFERENCES:

1. Judy W.M. Cheng, PharmD, FCCP, BCPS, Ranolazine for the Management of Coronary Artery Disease. Clinical Therapeutics/Volume 28, Number 12, 2006.
2. Delee, L. Le Garrec, l. Jullien, S. B~ranger, J. C. Pascal, H. Pinhas, Direct HPLC Resolution of Beta –Aminoalcohol (Tazifylline, Ranolazine, Sotalol) Enantiomers. Chromatographia Vol. 24, 1987.
3. Zhong, X. Q. Liu &, Y. Chen, X. P. Zhao, Y. S. Wang, G. J. Wang, Determination of Ranolazine in Rat Plasma by Liquid Chromatography–Electrospray Ionization Mass Spectrometry. Chromatographia 2006, 63, February (No. 3/4).
4. Uttam Bhaumik, Animesh Ghosh, Amlan Kanti Sarkar etal, Determination of ranolazine in human plasma by LC–MS/MS and itsapplication in bioequivalence study. Journal of Pharmaceutical and Biomedical Analysis 48 (2008) 1404–1410.
5. Madhavi, D. V. Subba Rao, P. Srinivasu, A. Naidu, Development and Validation of a New Analytical Method for the Determination of Related Components and Assay of Ranolazine in Bulk Drug and Pharmaceutical Dosage Forms by LC. Chromatographia 2009, 70, July (No. 1/2).
6. Herron, W. J.; Eadie, J.; Penman, A. D, Estimation of ranolazine and eleven Phase I metabolites in human plasma by liquid chromatography-atmospheric pressure chemical ionization mass spectrometry with selected-ion monitoring. Journal of Chromatography A (1995), 712(1), 55-60.
7. D. Penman , J. Eadie , W. J. Herron , M. A. Reilly , W. R. Rush , Y. Liu, The characterization of the metabolites of ranolazine in man by liquid chromatography mass spectrometry. Rapid communications in mass spectrometry, volume 9, issue 14, pages- 1418-1430.

Lei Tian, Juanjuan Jiang, Yiling Huang, Lu Hua, Hong Liu and Yishi Li, Sensitive quantification of ranolazine in human plasma by liquid chromatography–tandem mass spectrometry with positive electrospray ionization. Journal of Chromatography B, Volume 846, Issues 1-2, 346-350.