GB 22170-2008Pyrazosulfuron-ethyl wettable powder (English PDF)

4.1 Sampling

According to GB/T 1605-2001 "on solid preparation sampling" approach. Determining sample package using a random number table method; the final sample size not less than 300g.

4.2 Identification Test

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

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);

Filter. pore size of about 0.45µm;

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 liquid chromatogram topiramate ethyl WP shown in Figure 1.

1 --- topiramate ethyl.

Figure 1 topiramate ethyl WP liquid chromatogram

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 containing topiramate ethyl 0.05g sample (accurate to 0.0002g), a 50mL volumetric flask, add 40mL of methanol, into Ultrasonic bath sonication 5min. Removed, cooled to room temperature, add methanol to volume, shake; a membrane pore size of more than about 0.45µm Filter.

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 0.3%, the arithmetic mean value as a measurement result.

4.4 Determination of the suspension rate

4.4.1 Measuring step

According to GB/T 14825 performed. Weigh containing topiramate ethyl 0.10g sample (accurate to 0.0002g). With 60mL methanol cylinder the remaining 25mL of the suspension and the precipitate was all transferred to a 100mL flask, under ultrasonic oscillation 5min, cooled to room temperature, Methanol was added to volume, shake; filtered through a membrane filter pore size of about 0.45µm. 4.3 Determination by which topiramate ethyl quality.

4.4.2 Calculation

Suspension rate 2 (%) is calculated as follows.

× 111.1 (2)

A1 × 5

Where.

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

A2 --- sample solution by the remaining 25mL suspension and precipitate formulated in topiramate ethyl mean peak area;

1 --- sample topiramate ethyl mass fraction, expressed as a percentage;

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

4.4.3 Allowable difference

The difference between two parallel determination results shall not be greater than 5% of the arithmetic mean as a measurement result.

4.5 Determination of Moisture

According to GB/T 1600 in the "azeotropic distillation" method.

According to GB/T 1601 carried out.

4.7 Determination of wetting time

According to GB/T 5451 carried out.

4.8 Fineness

According to GB/T 16150 in the "wet sieve method".

4.9 Thermal storage stability test

According to GB/T 19136 in "powder formulations" to. After the heat storage mass fraction of topiramate ethyl, suspension rate is still 3.2 shall comply with the requirements.

4.10 Product inspection and acceptance

Shall comply with GB/T 1604's. Limit numerical processing using rounding value comparison method.