Purity determination for papaverine hydrochloride by perchloric aid titration | Autotitrator - JM Science
HIRANUMA APPLICATION DATA Automatic Titrator Data No. B19 Apr. 19,2018
Drugs and Medicines Purity determination for papaverine hydrochloride by perchloric aid titration

1. Abstract

Determination for papaverine hydrochloride is defined in Japanese Pharmacopoeia. Papaverine hydrochloride is used for improvement of vasodilatation and symptoms on gastritis, disease of biliary tract (gallbladder) system, acute arterial embolus, acute pulmonary embolism, peripheral circulatory failure, and inadequate coronary circulation.
The purity determination of papaverine hydrochloride using potentiometric titration with perchloric acid titrant is introduced in this report. Sample is dissolved by heating with acetic anhydride / glacial acetic acid mixture and cooled to room temperature. After that, the titration is performed, 1 mol papaverine hydrochloride reacts with 1 mol perchloric acid quantitatively.

Papaverine hydrochloride (C₂₀H₂₁NO₄・HCl, FW:375.85)

2. Configuration of instruments and Reagents

(1) Configuration of instruments
  Main unit : Hiranuma Automatic Titrator COM Series
  Electrodes : Glass electrode GE-101B
    : Reference electrode RE-201Z
Inner solution has to be changed to saturated sodium perchlorate in glacial acetic acid.
(2) Reagents    
  Titrant : 0.1 mol/L perchloric acid – acetic acid standard solution
  Titration solvent : Mixture of glacial acetic acid and acetic anhydride (3:7, v/v)
  Inner solution : Saturated sodium perchlorate in glacial acetic acid

3. Measurement procedure

(1) Take about 0.5 g of sample into 200 mL beaker and weigh accurately to 0.1 mg digits.
(2) Add 100 mL of titration solvent and dissolve sample by heating and stirring. After that, cool it down to room temperature.
(3) Immerse the electrode and titrate by 0.1 mol/L Perchloric acid – acetic acid standard solution.
Additionally, perform the blank test with the same procedure of sample measurement.

4. Measurement conditions and results

Examples of titration conditions

Measurement of blank

Measurement of blank

Measurement of sampleMeasurement of sample

Measurement results

Measurement of blank
Number of
Measurement
Size
(g)
Titrant
volume (mL)
1 0.010
2 0.010
Avg.
(Blank)
0.010 mL

 

Measurement of sample
Number of
Measurement
Size
(g)
Titrant
volume (mL)
Purity
(%)
1 0.4593 12.216 100.0830
2 0.4815 12.761 99.7310
3 0.4746 12.595 99.8637
Statistic
calculation
Avg.
SD
RSD
99.89 %
0.18 %
0.18 %

 

Examples of measurement curves

 

  • Measurement of blank

  • Measurement of sample

 

5. Note

(1) Temperature correction of perchloric acid standard solution
 This measurement determines the purity of the sample. Therefore, please pay attention for accurate weighing, measurement of factor or blank. Especially, the factor determination of perchloric acid – acetic acid standard solution should be regularly performed with potassium hydrogen phthalate. Acetic acid used as a solvent for the titrant has a relatively large thermal expansion coefficient. For example, a temperature change of 1 °C on this titrant causes a volume change of 0.1 %. Factor titration and sample measurement should be performed at the same room temperature as much as possible for accurate measurement.
 When the temperature of the sample measurement is different from that of factor titration, assign the following correction formula for titrant factor to the concentration calculation of sample.
  • F= F₀
    1+α(t-t₀)
  • F :Corrected factor at sample titration
    F₀:Factor at titrant factor determination
    α :Thermal expansion coefficient of titrant
      (Acetic acid=1.07×10⁻³)
    t :Temperature at sample titration
    t₀:Temperature at titrant factor determination
(2) Preparation of inner solution for reference electrode
 The inner solution of the reference electrode RE-201Z is filled with saturated KCl aqueous solution when purchased. This inner solution have to be replaced to saturated sodium perchlorate in acetic acid solution for this measurement. Replacement procedure is described below.
i) Prepare the saturated solution of sodium perchlorate in acetic acid with reagent grade of these.
ii) Discharge inner solution from reference electrode RE-201Z and wash inside it with water and then acetic acid.
iii) Fill the prepared inner solution into reference electrode from the supply port.
iv) Leave the electrode for one day before use.

 

Keywords: Drug, Papaverine hydrochloride, Japanese pharmacopoeia, Perchloric acid titration, Non-aqueous titration, Saturated sodium perchloric acid – acetic acid solution

*Some measurement would not be possible depending on optional configuration of system.

 

Drugs and medicines

Featured Instruments

Aquacounter Potentiometric Titrator COM-A19 | HiranumaAquacounter Potentiometric Titrator COM-A19 | Hiranuma
Hiranuma Aquacounter Potentiometric Titrator COM-A19 | Hiranuma
Sale price$11,490.00 USD Regular price$12,490.00 USD

Featured Titrators

View all
Aquacounter AQ-300 Coulometric Karl Fischer Titrator | Hiranuma
Hiranuma Aquacounter AQ-300 Coulometric Karl Fischer Titrator | Hiranuma
Sale price$5,500.00 USD Regular price$6,990.00 USD
Aquacounter Volumetric Karl Fischer Titrator MOIVO-A19 | Hiranuma
Hiranuma Aquacounter Volumetric Karl Fischer Titrator MOIVO-A19 | Hiranuma
Sale price$11,990.00 USD Regular price$13,990.00 USD
Aquacounter Coulometric Karl Fischer Titrator MOICO-A19 | Hiranuma
Hiranuma Aquacounter Coulometric Karl Fischer Titrator MOICO-A19 | Hiranuma
Sale price$10,990.00 USD Regular price$12,490.00 USD
Aquacounter Potentiometric Titrator COM-A19 | HiranumaAquacounter Potentiometric Titrator COM-A19 | Hiranuma
Hiranuma Aquacounter Potentiometric Titrator COM-A19 | Hiranuma
Sale price$11,490.00 USD Regular price$12,490.00 USD
Aquacounter AQV-300 Volumetric Karl Fischer Titrator | Hiranuma - JM Science
Hiranuma Aquacounter AQV-300 Volumetric Karl Fischer Titrator | Hiranuma
Sale price$5,500.00 USD Regular price$6,990.00 USD