GB 22168-2008Pyrazosulfuron-ethyl technical (English PDF)

4.1 Sampling

According to GB/T 1605-2001 "on the original drug product sampling" approach. Determining sample package using a random number table method; the final sample size not less than 250g.

4.2 Identification Test

IR spectra of infrared spectroscopy --- sample with topiramate ethyl standard infrared spectra (see Figure 1), there should be no significant difference.

Liquid chromatography --- The identification test can be carried out simultaneously with the determination of topiramate ethyl mass fraction. Under the same chromatographic operating conditions, Retention time with the standard solution of the sample solution to a peak of topiramate ethyl chromatographic retention time, the relative difference should be 1.5% Fewer.

Figure 1 topiramate ethyl standard infrared spectra

4.3 Topiramate ethyl mass fraction determination

4.3.1 Method summary

Samples dissolved in methanol, - water as the mobile phase, use ODSHypersil, 5µm as filler columns and variable wavelength UV Detectors, sample of topiramate ethyl liquid chromatography separation and determination.

4.3.2 Reagents and solutions

Methanol. HPLC grade;

Water. The new secondary steam distilled water;

Topiramate ethyl standard. a known mass fraction >=98.0%.

4.3.3 Instruments

LC. a variable wavelength UV detector and quantitative injection valve;

Chromatographic data processor or chromatography workstation;

Column. 4.6mm (i.d.) × 200mm stainless steel column, built ODSHypersil, 5µm filler (or with the same column efficiency Other reversed phase columns);

Ultrasonic bath;

Micro Injector. not less than 50µL.

4.3.4 HPLC operating conditions

Mobile phase. psi (CH3OH.H2O) = 70.30 (adjusted with phosphoric acid to pH = 3);

The mobile phase flow rate. 1.0mL/min;

Column temperature. room temperature (temperature change should not exceed 2 °C);

Detection wavelength. 241nm;

Injection volume. 10µL;

Retention time. topiramate ethyl approximately 8.0min.

HPLC operating conditions described above, the Department of typical operating parameters. According to the characteristics of different instruments, given operating parameters adjusted as appropriate, in order to obtain the best results. Typical original drug topiramate ethyl liquid chromatography is shown in Figure 2.

1 --- topiramate ethyl.

2-ethyl pyridine liquid chromatogram of the original drug

4.3.5 Measuring step

4.3.5.1 Preparation of standard solution

Weigh topiramate ethyl standard 0.05g (accurate to 0.0002g), placed in 100mL flask, add 80mL of methanol, add ultrasound Wave bath sonication 5min. Remove cooled to room temperature, add methanol to volume, shake; pipette imbibe 10.00mL, set in a 50mL volumetric flask, add methanol to volume, shake.

4.3.5.2 Preparation of the sample solution

Weigh the sample 0.05g (accurate to 0.0002g), placed in 100mL flask, add 80mL of methanol, in an ultrasonic bath Sonication 5min. Remove cooled to room temperature, add methanol to volume, shake; pipette imbibe 10.00mL, placed in a 50mL volumetric flask, add methanol to volume, shake.

4.3.5.3 Determination

Under the above chromatographic operating conditions, after the instrument is stable, continuous injection of several doses of the standard solution until the two adjacent needles topiramate ethyl relative peak area After the change of less than 1.0%, according to the order of the standard solution, sample solution, sample solution, standard solution injection analysis.

4.3.6 Calculation

The two needle sample solution measured before and after the peak area of the sample and two doses of the standard solution of ethyl topiramate were averaged. Sample topiramate Ethyl mass fraction of 1 (%) according to equation (1).

Where.

A1 --- standard solution Metsulfuron mean peak area pyrazosulfuron;

A2 --- sample solution topiramate ethyl Metsulfuron mean peak area;

--- Topiramate ethyl standard samples topiramate ethyl mass fraction, expressed as a percentage.

4.3.7 Allowable difference

The difference between two parallel determination results shall not be greater than 1.2%, the arithmetic mean value as a measurement result.

4.4 Determination of loss on drying

4.4.1 Instruments and Appliances

Weighing bottle. diameter 50mm, height 20mm;

Oven. 100 °C ± 2 °C;

Dryer.

4.4.2 Procedure

The weighing bottle placed in 100 °C ± 2 °C oven baking 1h, and then into the dryer to cool to room temperature, weighed (accurate to 0.0001g).

Repeat the above steps until constant weight weighing bottle. In weighing bottle was weighed into a 10g sample (paved weighed accurate to 0.0001g). Will be referred Flask back into the oven and bake uncovered 1h, the lid is removed and placed in a dryer 0.5h cooled weighed (accurate to 0.0001g). repeat the operation until the weighing bottle and the sample constant weight.

4.4.3 Calculation

2 samples of loss on drying (%) according to equation (2).

100 (2)

Where.

According to GB/T 1601 carried out.

4.6 Determination of dichloromethane insolubles

According to GB/T 19138 be taken to replace dichloromethane acetone.

4.7 Product testing and acceptance

Product inspection and acceptance shall comply with GB/T 1604's. Treatment of extreme values, using the rounding value comparison method.