Ganciclovir

English Name: ganciclovir

Alias: 9 - (1,3-dihydroxy-2-propoxymethyl) guanine

Molecular formula: c9h13n5o4

Molecular weight: 255.23

Purity: ≥ 98%

Physicochemical Properties: white or nearly colorless sodium salt powder, slightly soluble in water or glacial acetic acid, almost insoluble in methanol, and insoluble in dichloromethane; Slightly soluble in hydrochloric acid solution or sodium hydroxide solution

Laboratory analysis

Method name: ganciclovir raw material determination of ganciclovir nonaqueous titration

Application scope: this method uses titration to determine the content of ganciclovir in ganciclovir raw material.

This method is applicable to ganciclovir API.

Method principle: after the test article is dissolved with glacial acetic acid, add crystal violet indicator solution, titrate with perchloric acid titrant until the solution turns green, and correct the titration result with blank test. Calculate the content of ganciclovir according to the amount of titrant used.

Reagent: 1. Glacial acetic acid

2. Perchloric acid titrant (0.1mol/l)

3. Crystal violet indicator

4. Reference potassium hydrogen phthalate

Instrument and equipment:

Sample preparation: 1. Perchloric acid titrant (0.1mol/l)

Preparation: take 750ml of water-free glacial acetic acid (calculated by water content, add 5.22ml of acetic anhydride per 1g of water), add 8.5ml of perchloric acid (70-72%), shake well, cool, add an appropriate amount of anhydrous glacial acetic acid to 1000ml, shake well, and place for 24 hours. If the tested sample is easy to be acetylated, the water content of the solution shall be determined by moisture determination method, and then adjusted to 0.01% ~ 0.2% by water and acetic anhydride.

Calibration: take about 0.16g of reference potassium hydrogen phthalate dried at 105 ℃ to constant weight, accurately weigh, add 20ml of anhydrous glacial acetic acid to dissolve, add 1 drop of crystal violet indicator solution, slowly titrate to blue with this solution, and correct the titration result with blank test. Every 1ml of perchloric acid titrant (0.1mol/l) is equivalent to 20.42mg of potassium hydrogen phthalate. Calculate the concentration of the solution according to the consumption of the solution and the amount of potassium hydrogen phthalate.

2. Crystal violet indicator

Take 0.5g crystal violet and add 100ml glacial acetic acid to dissolve it.

Operation steps: accurately weigh about 0.15g of test sample, add 40ml glacial acetic acid, heat to dissolve, cool, add 1 drop of crystal violet indicator solution, titrate with perchloric acid titrant (0.1mol/l) until the solution turns green, and correct the titration result with blank test. Every 1ml of perchloric acid titrant (0.1mol/l) is equivalent to 25.52mg of c9h13n5o4.

Note: "precise weighing" means that the weight should be accurate to one thousandth of the weight. "Precision measurement" means that the accuracy of the measured volume shall meet the accuracy requirements of the national standard for the pipette of this volume.

Reference: Pharmacopoeia of the people's Republic of China, compiled by the national pharmacopoeia committee, chemical industry press, 2005 edition, Volume II, p.239.