UV Spectrophotometric Estimation of Voriconazole in Tablet Dosage Form

 

N. Tamilselvi*, Babikir Hassan, Fagir Babikir Fadul, Deepthi Kondapalli, Kandimalla Anusha and Dona Sara Kurian

K.M.C.H College of Pharmacy, Kalapatty Road, Kovai Estate, Coimbatore-641048.

*Corresponding Author E-mail: tamildeiva@yahoo.co.in

ABSTRACT:

A new, simple, specific, sensitive, rapid and economical procedure has been developed and validated for the estimation of voriconazole in its dosage form. Standard stock solution was prepared in methanol and further dilutions were carried out with same solvent. The resulting solutions were then scanned in the UV range (200-400nm) in a 10mm matched quartz cells in double beam UV-Visible spectrophotometer. The drug shows maximum absorption at 256 nm. The drug obeyed Beer’s law in the concentration range of 5-30µg/ml with molar absorpitivity of 3.951x10 ⁴ l/mol.cm in methanol. Regression equation was found to be 0.03x-0.004 and coefficient of correlation was 0.999. The result of estimation of marketed tablet formulation was found to be 99.71±0.002 with their %RSD less than 2. Recovery studies were carried out by the addition of known amount of standard drug (80,100 and 120% of labeled claim of the tablet) to the preanalysed tablet solution. The % recovery was found to be 99.73±0.002.the intraday and interday assay result was within 2%. The methods were then validated statistically as per the ICH guidelines which yielded good results concerning range, precision, accuracy, robustness and ruggedness.

 

 

INTRODUCTION:

Voriconazole¹, is chemically (2R, 3S)-2-(2, 4diflurophenyl)-3-5-fluoro-4-pyrimidinyl)-1-(1H-1, 2, 4-triazole1-yl)-2-butanol with an empirical formula of C16H14N5F3 and a molecular weight is 346.50. It is a broad spectrum triazole antifungal agent. The primary mode of action of voriconazole is the inhibition of fungal cytochrome P-450 mediated 14-alpha-lanosterol demethylation, an essential step in fungal ergosterol biosynthesis².

 

The chemical structure of voriconazole was derived from that of fluconazole by replacement of one triazole moiety by a fluoropyrimidine group and α-methylation. This modification resulted in an enhanced spectrum of antifungal activity and increased in vitro potency.

 

Voriconazole is available in both oral and intravenous formulations. Literature reveals that there are few microbiological³ , UV⁴ and HPLC^5-12. methods have been developed for the estimation of voriconazole.  In the present investigation an attempt was made to develop a simple, and economic  UV- spectrophotometric method for the analysis of voriconazole in tablet dosage form¹³.

 

MATERIALS AND METHODS:

A double-beam Shimadzu UV-visible spectrophotometer (model 1700), with spectral bandwidth  of 2nm, wavelength accuracy ± 0.5 nm and a pair of 1cm matched quartz cells was used to measure absorbance of the resulting solution. Analytical grade solvents were used in the present study. A drug sample of voriconazole was procured from M/s Natco Pharmaceuticals, Nagarjuna Sagar. Commercial tablets of voriconazole were purchased from the local market.

 

 

DETERMINATION OF LINEARITY RANGE:

Voriconazole was weighed accurately (10mg) transferred into a 10ml standard volumetric flask, dissolve with methanol and made up to the volume with methanol. The final solution had a concentration of 1000µg/ml (solution A). Accurately pipetted out 1 ml of solution A into a 10 ml standard flask and made up to the volume using methanol to get a concentration of 100mg/ml (solution B). Accurately pipette out 0.5ml, 1.0ml, 1.5ml, 2.0ml, 2.5ml and 3.0ml of solution B into six separate 10ml standard flask and made up to the volume with methanol to get a concentration of 5, 10, 15, 20, 25, 30µg/ml (solution C). One of the above solutions was scanned in UV range using methanol as blank and wavelength of maximum absorption was found to be about 256nm. The absorption solutions of different concentration were measured at 256nm. The UV spectrum for the above drug is represented in Fig.1.

 

Calibration curve was plotted between absorbance vѕ concentration. Voriconazole showed linearity range from 5-30µg/ml at the selected wavelength. From the prepared dilutions a standard curve is plotted by determining the concentration using 256nm wavelength(Fig.2). Optical characteristics are presented in( Table-1).

 

Fig 1: UV spectrum of voriconazole

 

Fig 2:  Calibration curve of Voriconazole

 

Table 1: Optical characteristics and precision data of Voriconazole

PARAMETER	VALUE
λ max(nm) Beer’s law limit (μg/mL) Molar absorptivity(L/mol cm) Correlation coefficient (R) Sandell sensitivity(μg/cm2/0.001AU) Regression equation(y=mx+c) Intercept (a) Slope (b)	256 5 to 30 3.951x104 0.999 1.94x10-2 Y=0.030x-0.004 -0.004 0.0300

 

ANALYSIS OF VORICONAZOLE:

Commercial formulations, Vori-I and Vori-II S were purchased from a local pharmacy. Twenty tablets of each brand of voriconazole were weighed and finally powdered in a mortar. A quantity equivalent to 10mg of voriconazole was weighed accurately and dissolved in methanol and made up to 10ml in volumetric flask with water. The solution was then filtered through Whatman filter paper No:41, to get a clear solution. From this 1ml of solution was drawn and make up to 10ml with water. The formulations were estimated in three concentration range by diluting stock solutions to 10µg/ml of voriconazole. The method was validated according to ICH guidelines. The results obtained are given in (Table-2).

 

Table-2: Results of the estimation of Voriconazole in tablet

Tablet Formulation	Label claim (mg/tablet)	Amount    found(mg)	% Recovery ±SD
Vori-I	20	19.8	99.7±0.2
Vori-II	20	19.8	99.7±0.1

Average of three determinations

 

RECOVERY STUDIES:

Recovery studies were carried out at three different levels by adding 1, 2, 3 mg/ml of pure drug solution to different samples of tablet powder solution containing the equivalent 20mg/ml of drug. From the amount of drug found, percentage recovery was calculated.

 

RESULTS AND DISCUSSION:

The proposed method for determination of voriconazole showed molar absorptivity 3.951x10⁴l/mol.cm.

Linear regression of absorbance on concentration gave the equation y=0.030x-0.004 with a correlation (r²) of 0.999(Table-1).

Voriconazole exhibited maximum absorption at 256 nm and obeyed Beer’s law in the range of 5-30µg/ml. The percentage recovery value was 99.7% indicates that there is no interaction of the excipients present in the formulations. The study was made to test ruggedness of the method through an interday and intraday analysis of samples.

 

CONCLUSIONS:

Based on the results obtained, it is found that the proposed method of analysis is accurate, precise, reproducible and economical and can be employed for the routine quality control of voriconazole in tablet  formulations.

 

ACKNOWLEDGEMENT:

The authors are thankful to the Director of K.M.C.H. College of Pharmacy for providing facility regarding work.

 

REFERENCES:

1.        K.Richardson, et al, Abstr.35^thIntersci.Conf.Antimicrob.Agents    Chemother, Abstr.F69;1995: 125.

2.        P.T.Troke,et al, Abstr35th Intersci.Conf.Antimicrob.Agents Chemother,Abstr.F70;1995:125.

3.        S.Perea,et al, Antimicrob.AgentsChemother,44;2000:1209.

4.        AnuRekha Jain,et al, UV spectrophotometric Estimation of voriconazole in Bulk & Tablet dosage form, Department of pharmaceutical chemistry, Asian journal of chemistry21(2); 2009:1627-1629.

5.        G.J.Pennick,et al, Antimicrob.AgentsChemother,44;2003: 2348.

6.        Srinubabu,et al,Talanta,71; 2007:1424.

7.        D.Stopher and R.Gage,J.Chromatogr.B,691; 1997: 441

8.        B.Sridhar, et al, validated RP-HPLC method for the estimation of voriconazole in Bulk & Tablet dosage form, Department of Pharmaceutical sciences, Indian journal of research in Pharmaceutical & Biosciences,1(1); July-sep 2010:14-18.

9.        Randolph D, et al, Detemination of voriconazole in aqueous humour by liquid chromatograpy-electrospray,ionization-mass-spectroscopy,Department  of ophthalmology, Journal of chromatography B776;2002:213- 220.

10.     Markus Wenk, et al , Fast and reliable determination of the anti fungal drug voriconazole in plasma using monolithic silica rod liquid chromatography, Department of clinical pharmacology and Toxicology, Journal of chromatography B,832; 2006:313-316.

11.     Richard Gage and David A. Stopher, HPLC assay for voriconazole in human plasma, Department of Drug Metabolism, Journal of pharmaceutical and Biomedical Analysis,17; 1998:1449-1453.

12.     Teresa Araujo and  Conrado, Plasma, Validation of LC-MS/MS method for determination of  voriconazole in rat plasma, clinical pharmaceutics, Journal of pharmaceutical & Biomedical Analysis,44; 2007: 985-900.

13.     A.H. Beckette and Stenlake, Practical Pharmaceutical Chemistry, 1986;Vol.2, edn.2 .

 

 

 

 

Received on 30.08.2011          Modified on 07.09.2011

Accepted on 11.09.2011         © RJPT All right reserved