Introduction

Gefitinib is a drug newly listed in the 18th edition of the Japanese Pharmacopoeia (JP), and is used in the treatment of non-small-cell lung cancer, especially when surgery is difficult. This drug selectively inhibits the activity of the epidermal growth factor receptor (EGFR) tyrosine kinase that has undergone a genetic mutation, and suppresses the growth of cancer cells.

In this report, we present the results of purity tests and assays on gefitinib in accordance with the Japanese Pharmacopoeia, 18th Edition.

LC-4500 series HPLC system

Experimental

Instruments
Pump:  PU-4580
Degassing unit:  DG-4580
Autosampler:   AS-4550
Column oven:  CO-4060
UV detector:  UV-4570

Conditions
Column: Unifinepak C18 (3.0 mmI.D. x 100 mmL, 3 µm)
Eluent: Ammonium acetate solution (Dissolve 3.0 g ammonium acetate with water and fill up to 310 mL.)/acetonitrile (31/19)
Flow rate: 0.9 mL/min
Column temp: 60 ºC
Wavelength: 247 nm
Injection volume: 5 µL
Standard: Gefitinib (The dissolving and diluting solvent is a mixture of 0.2 % trifluoroacetic acid aqueous solution /acetonitrile (3:2).)

Structure

Gefitinib

Keywords

Japanese Pharmacopoeia, gefitinib, UV detector

Results

An overview of the system suitability for purity tests and assays on gefitinib is shown in Table 1.

Table 1   Overview of system suitability tests for gefitinib purity tests and assays

(1) Purity
Figure 1 shows the detectability results for the purity test. For the standard solution diluted to 0.175 mg/L, the SN ratio for the bicalutamide peak was 50.7, which meets the criterion of ≥10.

Fig. 1   Chromatogram of gefitinib for detectability test (0.175 mg/L)

Figure 2 shows chromatograms of gefitinib standard solutions (n = 6), and Table 2 shows the results for peak area reproducibility based on the measured system reproducibility for the purity test. The relative standard deviation of the peak area was 0.26 %, which met the criterion of ≤2.0 %

Fig. 2   Chromatogram of gefitinib standard solution (0.35 mg/L, n = 6)

Table 2 Gefitinib peak area reproducibility (n = 6)

(2) Assay
Figure 3 shows a chromatogram of a standard solution of gefitinib containing 3,4-dichloroaniline (250 mg/L and 350 mg/L, each). 3,4-Dichloroaniline and gefitinib eluted in that order, and the resolution for the peaks was 9.0, which met the criterion of ≥ 5.

Fig. 3   Chromatogram of 3,4-dichloroaniline + gefitinib
(250 mg/L, 350 mg/L each)

Figure 4 shows chromatograms of the standard solution for the assay of gefitinib (n = 6), and Table 3 shows the results for peak area reproducibility based on the measured system reproducibility for the assay. The relative standard deviation of the peak area was 0.11 %, which met the criterion of ≤1.0 %.

Fig. 4   Chromatogram of gefitinib standard solution (350 mg/L, n = 6)

Table 3   Gefitinib peak area  reproducibility (n = 6)

Conclusion

We performed system suitability tests for the purity tests and assays of gefitinib, which is newly listed in the 18th edition of the Japanese Pharmacopoeia. As shown in Table 4, all of the evaluation results met the specified criteria for the Japanese Pharmacopoeia.

Table 4   Results of system suitability for purity tests and assays of gefitinib