Quantitative Estimation of Sorafenib Tosylate Its Pure Form and in Its Tablet Formulation by RP-HPLCMethod

A simple, accurate, speci�c reverse-phase, high-performance liquid chromatography method has been developed for the determination of sorafenib tosylate in its pure form and its tablets. In this method, sorafenib tosylate was eluted by isocratic mode using a Phenomenex Luna C18 column by a mobile phase composition of acetonitrile and water in the ratio of 82.5 : 17.5, v/v. e �ow rate was 1.5mL/min. e eluted drug was monitored at 265 nm and the method was found to be linear from 5 to 80 μμg/mL. e method was validated by linearity, precision, accuracy, LOD, and LOQ. e accuracy report denotes that there is not any interference of additives used in the formulation.


Experimental Methods
Sorafenib tosylate pure drug was obtained as a gi sample from Natco pharma (Hyderabad, India).All the reagents used were HPLC grade.
2.1.Instrumentation.e HPLC experiment was carried out in a Shimadzu HPLC system equipped with Phenomenex Luna C18, 5 m (4.6 × 250 mm) column, two LC-20AD pumps, SCL-10AVP system controller, Rheodyne injector with 50 L loop, and SPD-20A UV-visible detector, and LC Solution soware was used.All the reagents used were HPLC grade.e mobile phase was a mixture of acetonitrile and water (82.5 : 17.5, v/v) that was set at a �ow rate of 1.5 mL/min.

Drug Stock Solution.
Stock solution of sorafenib tosylate was prepared by dissolving accurately weighed 100 mg of the pure drug in 100 mL of mobile phase (�nal concentration, 1 mg/mL).e prepared stock solution was stored at 4 ∘ C and protected from light.

Calibration Curve.
From the above stock solution, 10 mL was taken and diluted to 100 mL with mobile phase.Subsequent dilutions of this solution ranging from 5-80 g/mL were made in 10 mL volumetric �asks.e solutions were �ltered through 0.45 m membrane �lters and then 50 L of �ltrate was injected each time into the column at �ow rate of 1.5 mL/min.Evaluation of the drug was performed with UV detector at 265 nm.Peak area was recorded for all peaks.
A plot of peak area versus the respective concentration gives the calibration curve.e regression of drug concentration over the peak area was computed.Unknown samples were estimated by reference to this calibration curve.

Sample Preparation.
Twenty tablets were weighed accurately and crushed to �ne powder.From that, the amount of powder equivalent to 100 mg of sorafenib tosylate was weighed accurately and transferred to a 100 mL volumetric �ask.Mobile phase (50 mL) was added and the mixture was sonicated for 10 min, for complete extraction of the drug, and the solution was diluted to volume with mobile phase.en solution was centrifuged at 4000 rpm for 10 min, and the clear supernatant was collected and �ltered through a 0.2 m membrane �lter.From this solution 10 mL was taken and diluted to 100 mL with mobile phase, again 4 mL was diluted to 10 mL to get 40 g/mL solution, of which 50 L was injected for HPLC analysis.

Results and Discussion
A typical chromatogram of sorafenib tosylate was shown in Figure 1.e retention time for sorafenib tosylate was 3.4 min.Flow rate was �xed at 1.5 ml/min, which gives tailing factor in the acceptable limit.e peak areas from such different concentrations of 5 to 80 g/mL were calculated.A good linear relationship ( 2 = 0.998) was observed between the concentration drug and the respective peak area.e regression curve was constructed by linear regression �tting.e intraday and interday variations of the method were determined, a low coefficient of variation was observed.is shows that the present HPLC method is highly precise.To ensure accuracy of the method, recovery studies were carried out mixing a known quantity of drug with preanalyzed sample and the contents were reanalyzed by the proposed method.e recovery was about 99.95% to 100.23% (Table 2), indicating the high accuracy of the proposed HPLC method.e drug content in tablets was quanti�ed using the proposed analytical method and the results are shown in Table 1.Chromatographic parameters such as peak asymmetry and capacity factor were found to be 1.03 and 0.921, respectively.e limit of detection (LOD) and limit of quanti�cation (LOQ) were found to be 0.133 and 0.403 g/mL, respectively.e precision of the method was calculated in terms of the relative standard deviation.Low values of relative standard deviation indicated high precision and accuracy of the proposed method.

Conclusion
e developed RP-HPLC method was simple, sensitive, precise, and accurate and hence can be used in routine for the determination of sorafenib tosylate in pure as well as in tablets.

Con�ict o� �nte�ests
e authors declare that there is no con�ict of interests.

F 1 :
A typical chromatogram of sorafenib.
T 1: Assay results and precision studies.
a Mean of six determinations.