Detection method of polyethylene glycol monomethyl ether residue in medicinal materials

Abstract

A detection method of polyethylene glycol monomethyl ether residue in medicinal materials is provided, which belongs to a technical field of medicinal chemical component detection, and includes: detecting a residual amount of mPEG-2000 in 3000-3400 small-molecule mPEG-b-PDLLA by high-performance liquid chromatography with an evaporative light scattering detector. The present invention solves a problem that the copolymer polyethylene glycol monomethyl ether mPEG and the product polyethylene glycol monomethyl ether-polylactic acid block copolymer mPEG-b-PDLLA are difficult to be separated in the high-performance liquid chromatography and there is no UV absorption. The present invention also has high resolution, high sensitivity, sufficient reproducibility and sufficient selectivity.

Claims

1. A detection method of polyethylene glycol monomethyl ether residue in medicinal materials, comprising: detecting a residual amount of mPEG-2000 (polyethylene glycol monomethyl ether) in 3000-3400 small-molecule mPEG-b-PDLLA (polyethylene glycol monomethyl ether-polylactic acid) by high-performance liquid chromatography with an evaporative light scattering detector.

2. The detection method, as recited in claim 1, specifically comprising steps of: 1) setting chromatographic conditions: for the evaporative light scattering detector, a gain: 100-200, a drift tube temperature: 90-100 C., and a physicochemical gas pressure: 35-40.0 psi; for a liquid chromatography column with a high-purity silica gel matrix as a filler, a flow rate: 0.8-1.0 ml/min; a column temperature: 25-35 C.; an injection volume: 20 L; for a mobile phase A: a volume ratio of 95:5 of 0.3 mmol/L ammonium acetate solution: acetonitrile, containing 0.2% acetic acid; for a mobile phase B: a volume ratio of 5:95 of 0.3 mmol/L ammonium acetate solution: acetonitrile, containing 0.2% acetic acid; 2) drawing a standard curve, which specifically comprises steps of: dissolving a mPEG-2000 reference substance in the mobile phase A to prepare mPEG-2000 standard solutions with different gradient concentrations between 25 g/mL and 100 g/mL, and detecting after filtration at 0.45 microns; during detecting, processing the mobile phase A and the mobile phase B with gradient elution: 0-10 minutes from elution start, the mobile phase A 85%, the mobile phase B 15%; 11-30 minutes from elution start, the mobile phase A 65%, the mobile phase B 35%; 31-40 minutes from elution start, the mobile phase A 50%, the mobile phase B 50%; 41-45 minutes from elution start, the mobile phase A 85%, the mobile phase B 15%: and using logarithmic values of chromatographic peak areas as ordinates and logarithmic values of concentrations of the mPEG-2000 standard solutions as abscissas, plotting test results of the high-performance liquid chromatography as standard curves and then fitting to obtain a standard curve equation:
Y=KX+b, wherein Y refers to the logarithmic values of the chromatographic peak areas, X refers to the logarithmic values of the mPEG-2000 concentrations, and K and b are constants; 3) preparing a test sample, which specifically comprises steps of: preparing the mPEG-b-PDLLA into a sample solution with a concentration of about 99-10.5 mg/mL with the mobile phase A; and 4) detecting, which specifically comprises steps of: loading the sample solution, and then loading the MPEG-2000 standard solutions; comparing chromatograms of the sample solution and the standard solutions; identifying the mPEG-2000 in the sample solution by a relative retention time between the sample solution and the standard solutions; placing a logarithmic value of a chromatographic peak area of the mPEG-2000 in the test sample into the standard curve equation to calculate a concentration of the mPEG-2000 in the sample, and then calculating residual amount of the mPEG-2000 by an external standard method.

3. The detection method, as recited in claim 2, wherein a specification of the liquid chromatography column with the high-purity silica gel matrix as the filler is 4.6 mm250 mm, 5 m.

4. The detection method, as recited in claim 2, wherein the mPEG-2000 reference substance is dissolved in the mobile phase A to prepare the mPEG-2000 standard solutions with concentrations of 100 g/ml, 50 g/ml, and 25 g/ml.

5. The detection method, as recited in claim 3, wherein the mPEG-2000 reference substance is dissolved in the mobile phase A to prepare the mPEG-2000 standard solutions with concentrations of 100 g/ml, 50 g/ml, and 25 g/ml.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] FIG. 1 is a chromatogram of a blank solvent;

[0035] FIG. 2 is a chromatogram of a reference substance;

[0036] FIG. 3 is a standard curve of polyethylene glycol monomethyl ether-2000 (mPEG-2000);

[0037] FIG. 4 is a chromatogram of a polyethylene glycol monomethyl ether-polylactic acid block copolymer (mPEG-b-PDLLA) sample.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0038] The following is merely a preferred embodiment of the present invention, and are not intended to be limiting in any way. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention shall be included in the protection scope thereof.

[0039] A detection method of polyethylene glycol monomethyl ether residue in medicinal materials comprises steps as follows.

[0040] I. Chromatographic conditions:

[0041] 1. Chromatographic column: liquid chromatography column (4.6 mm250 mm, 5 m) with high-purity silica gel matrix as filler;

[0042] 2. Detector: waters2424 evaporative light scattering detector, instrument to parameters: gain: 100, drift tube temperature: 100 C., physicochemical gas (air) pressure: 40.0 psi;

[0043] 3. Mobile phase:

[0044] Mobile phase A: 0.3 mmol/L ammonium acetate solution-acetonitrile (volume ratio 95:5, containing 0.2% acetic acid)

[0045] Mobile phase B: 0.3 mmol/L ammonium acetate solution-acetonitrile (volume ratio 5:95, containing 0.2% acetic acid);

[0046] perform gradient elution according to the following table:

TABLE-US-00001 Time (min) Mobile phase A (%) Mobile phase B (%) 0 85 15 10 65 35 30 50 50 40 60 40 43 85 15

[0047] 4. Flow rate: 0.8-1.0 ml/min;

[0048] 5. Column temperature: 25-35 C.;

[0049] 6. Injection volume: 20 L.

[0050] II. Standard curve:

[0051] accurately weighing polyethylene glycol monomethyl ether-2000 reference substance and dissolving in the mobile phase A, and using the mobile phase A to prepare reference solutions with a concentration of C1=100 g/ml; C2=50 g/ml; C3=25 g/ml; loading the mobile phase A and the reference solutions with three different concentrations after passimg through a 0.45 m filter; using the mobile phase A as a blank solvent, and a chromatogram thereof is shown in FIG. 1; wherein a peak chromatogram of the polyethylene glycol monomethyl ether-2000 (mPEG-2000) reference substance is shown in FIG. 2; test results are shown in Table 1.

TABLE-US-00002 TABLE 1 test results of reference substance with different concentrations Concentration Logarithm of Logarithm of (g/ml) concentration Peak area peak area Reference 1 100.2 2.0009 11671564 7.0671 Reference 2 50.1 1.6998 4974625 6.6968 Reference 3 25.05 1.3988 1885070 6.2753

[0052] using logarithmic values of chromatographic peak areas as ordinates and logarithmic values of concentrations of the mPEG-2000 standard solutions as abscissas, plotting test results of the high-performance liquid chromatography as standard curves and then fitting to obtain a standard curve equation: Y=1.31.51 X+4.4444, regression coefficient R.sup.2=0.9986, and the standard curve of the polyethylene glycol monomethyl ether-2000 (mPEG-2000) is shown in FIG. 3.

[0053] III. Sample testing:

[0054] accurately weighing 0.5 g polyethylene glycol monomethyl ether-polylactic acid block copolymer (mPEG-b-PDLLA), diluting with the mobile phase A and dissolving in a 50 mL, volumetric flask; metering volume and shake well; loading and detecting according to the above instrument conditions after passing through a 0.45 m filter; placing a logarithmic value of a chromatographic peak area obtained into the standard curve equation, and then calculating residual amount of the mPEG by an external standard method, which is 0.08%; wherein sample chromatogram of the polyethylene glycol monomethyl ether-polylactic acid block copolymer (mPEG-b-PDLLA) is shown in FIG. 4.

[0055] IV. Analysis of Results 1. Curve linearity: according to the above method, using logarithmic values of chromatographic peak areas as ordinates and logarithmic values of concentrations of the mPEG-2000 standard solutions as abscissas, plotting test results of the high-performance liquid chromatography as standard curves and then fitting to obtain a standard curve equation: Y=1.3151 X+4.4444, regression coefficient R.sup.2=0.9986, indicating that the polyethylene glycol monomethyl ether-2000 standard solution has good linearity in the concentration range of 25 g/ml-100 g/ml.

[0056] 2. Precision: using 50 g/mL polyethylene glycol monomethyl ether-2000 standard solution, loading 20 L each time, and performing 6 consecutive loading; detecting according to the above chromatographic conditions, recording peak areas, and calculating the precision; wherein the peak areas of the six loadings of the precision experiments were 4984625, 4976305, 4965280, 4975876, 4964958, and 4975628; relative deviation calculated based on the peak areas was 0.15%, indicating good precision.

[0057] 3. Reproducibility: taking the sample solution processed according to the above method, which has a concentration of about 20 mg/mL, loading 20 L each time, and performing 6 consecutive loading; detecting according to the above chromatographic conditions, recording peak areas, and calculating the reproducibility; wherein the peak areas of the six loadings of the reproducibility experiments were 543699, 534580, 523416, 534610, 534582, 528706; relative deviation calculated based on the peak areas was 1.3%, indicating good reproducibility.

[0058] 4. Stability: using 50 g/mL polyethylene glycol monomethyl ether-2000 standard solution, placing at room temperature, and loading at 0 h, 2 h, 4 h, 8 h, 12 h and 24 h with 20 L each time; detecting according to the above chromatographic conditions, and comparing the stability of the results; wherein the peak areas of the six loadings of the stability experiments were 4978623, 4988315, 4975480, 4968654, 4987521, and 4979156; relative standard deviation calculated based on the peak areas were 0.15%, indicating that the polyethylene glycol monomethyl ether solution is to relatively stable after placing at room temperature for 24 h.