Introduction

Alfuzosin hydrochloride¹, (R,S)-N-[3-[(4-amino-6,7-dimethoxy-2-quinazolinyl) methylamino] propyl] tetrahydro-2-furan carboxamide hydrochloride is antagonist of α₁ adrenergic receptors used in the treatment of prostatic hyperplasia^1-3. Alfuzosin hydrochloride is official in BP 2003. Litrature survey revealed chromatographic and non-aqueous methods  for estimation of alfuzosin hydrochloride in bulk, pharmaceutical formulations and biological fluids ^4-8.

Present work deals with UV-spectrophotometric method for estimation of Alfuzosin hydrochloride from bulk and tablets.

Meterials and Method

Instrumentation

Spectral and absorbance measurements were made with Shimadzu UV-Visible Double beam Spectrophotometer model- 1700 with pair of 10mm matched quartz cells.

Reagents

All the chemicals used were of analytical grade. All the solution were freshly prepared with double distilled water. Pure raw material of alfuzosin  hydrochloride was obtained as a gift sample from Aurobindo Pharma Limited, Hyderabad. The formulations  used were purchased from local pharmacy.

Preparation of standard stock solution

Standard stock solution was prepared by dissolving 25mg of alfuzosin hydrochloride in 100 ml of 0.1M NaOH to get concentration of 250 µg/ml. Different aliquots were taken from the stock solution and diluted to 25 ml mark with same  solvent to obtain series of concentration. The solutions were scanned on spectrophotometer-1700 (Shimadzu) in the UV range 200-400 nm and absorbances were recorded at 350nm against blank.

Preparation of sample solution

For analysis of commercial formulations, twenty tablets were weighed, average weight was determined and crushed into fine powder. A quantity of tablet powder equivalent to 25 mg of alfuzosin HCl was transferred into 250 ml volumetric flask, added 50 ml of 0.1 M NaOH and sonicated for five minutes and repeated the sonication consequently by four times (4×50 ml) to produce 250 ml.  The solution was filtered through whatmann filter paper no.41. After appropriate dilutions, absorbance of the sample solutions were recorded at 350 nm and the concentration of the drug was calculated from linear regression equation; results are shown in Table 1.

Table 1: Results of assay.

*mean of six observations

Recovery studies

To study the accuracy of the proposed method, recovery experiments were carried out by adding a known amount of drug to pre analysed sample at three levels and the percentage recoveries were calculated; the results are summarized in Table 2.

Table 2: Summary of validation.

* mean of three estimation at each levels.

Results and Discussion

The l_max of alfuzosin hydrochloride in 0.1M NaOH was found to be 350 nm. The drug follows linearity in the concentration range of 10-30 µg/ml (Y=0.01336X+0.0088; r²=0.999914). The analysis of tablet formulations by proposed method was in good agreement with label claim. The recovery studies were carried out at three different levels i.e. 50%, 70% and 90%.The low values of %RSD are indicative of the accuracy of the method. Recovery experiments indicated the absence of interferences from the commonly encountered pharmaceuticals additives and excipients. The precision of the method was studied as an intra-day and inter-day precision. The results from validation studies are shown in Table 2.

The proposed method is simple, rapid, accurate , economical and useful for the routine analysis of alfuzosin hydrochloride from marketed formulations.

Acknowledgement

The authors are thankful to Management, Adhiparasakthi College of Pharmacy, Melmaruvathur for providing facilities to carry out this work. They also thankful to  Aurobindo Pharma Limited, Hyderabad for the gift sample of alfuzosin hydrochloride.

References

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3. British Pharmacopoeia, Volume. I, The Department of Health, London, 81(2003)
4. Wei, X., Yin, Yang, G., He, C. and Chen, Y. “Online solid phase extraction with a monolithic weak cation-exchange column and simultaneous screening of alpha1 adrenergic receptor antagonist in Human Plasma”. J. Sep. Sci. 30(17):2851-7( 2007).
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6. Salah Fayed, A., Abdel Aaty Shehata, M., Yehia Hassan, N. and El-Weshahy, Sa. “Validated HPLC and HPTLC stability indicating methods for determination of Alfuzosin HC1 in bulk and pharmaceutical formulation”. J. Sep. Sci. 29(18): 2716-24 ( 2006).
7. Chandra, A., Channabasavaraj, K. P., Manohara, Y. N. and Ankita, S. M. “Development and validation of RP-HPLC method for the estimation of Alfuzosin HC1 in bulk and tablets”. Indian Drugs. 44: 555-558 (2007).