Calibration of Polarimeter , Purpose :
Calibration of Polarimeter , The purpose of this SOP is to describe the operation, calibration and cleaning of Polarimeter (Model: Rudolph, AUTOPOL IV) used for the determination of the optical rotation in quality control laboratory at XX Pharmaceuticals Ltd.
Calibration of Polarimeter , Scope :
This procedure describes the application of Polarimetric determinations of optical rotation of raw materials (active & excipients), intermediates and drug product etc. in the quality control laboratory of general block at XX Pharmaceuticals Limited.
Definitions/Abbreviation:
Standard Operating Procedure (SOP): A written authorized procedure, which gives instructions for performing operations.
Responsibilities:
The roles and responsibility is as follows:
Officer/Executive/ Sr. Executive, Quality Control
[][]To ensure that this procedure is followed.
[][]To maintain the records properly as per SOP.
Manager, Quality Control
[][]To ensure that this procedure is kept up to date.
[][]To confirm that the SOP is technically sound and reflects the required working practices.
[][]Arrange training on the SOP to all concerned personnel.
[][]To ensure implementation of the SOP after training.
[][]Schedule calibration of the instrument at the defined intervals.
Head of Quality Assurance
[][]Approval of the SOP.
[][]To ensure overall implementation of this SOP.
Procedure:
Precaution(s):
[][]The equipment should not be set near to room heating equipment or direct sunlight.
[][]Not to spill water or sample on the main body of the instrument.
[][]Use the instrument at an ambient temperature of 5°C to 35°C and RH lower than 90%.
[][]Disconnect the power supply before moving or cleaning of the instrument.
General procedure:
Polarimetry is used to measure the effect that an optically active molecule in solution has on polarized light. Specific Optical Rotation is defined as an Observed Optical Rotation, measured at a specific wavelength and temperature, corrected for the path length of the optical cell and concentration of the solution. The sample is normally presented to the Polarimeter as a solution, contained in a thermally controlled optical cell. A beam of polarised light is then passed through this cell and any rotation of this polarised light is measured via a detector
Reagent quality:
[][]If water is used in the preparation of sample solutions, it must be purified by distillation or deionization process.
Instrument equilibration:
[][]The instrument must be equilibrated before use. The polarimeter (set to required wavelength), must be switched on for a minimum of at least 30 minutes before use.
Preparation and storage of samples:
[][]Sample solutions must be prepared in accordance with the analytical method. Sample solutions must be discarded at the end of the working day, unless solution stability has been demonstrated.
Preparation for measurement:
[][]Connect the power cable and turn the Polarimeter ON.
[][]Press Menu to select the measurement settings.
[][]Press Scale button and select the specific optical rotation.
[][]Press Temperature correction and select off mode.
[][]Press Statistics button and select on (n-1).
[][]Exit from the Menu by pressing Exit button.
[][]Fill the Polarimeter cell with sample blank and place it into the sample chamber.
[][]Press Zero button for zeroing the sample blank.
[][]Then remove the cell from the sample chamber and discard the sample blank and rinse the cell with the sample.
[][]Fill the cell with the sample and press Measure.
[][]Type the Lot ID and press Enter.
[][]Input the sample weight and press Enter.
[][]Type the Sample Name again presses Enter.
[][]When the measurement completed, press Print Option to the results.
[][]Remove the polarimeter cell from the chamber.
Calculation of Specific Optical Rotation:
The specific optical rotation of a sample is calculated as follows:
A=αx100/I x c
Where,
[α] = Specific Rotation at Temperature, T°C and wavelength, λ nm
Α = Observed Rotation in degrees (°)
l = Path length in decimeters (dm)
c = Concentration of analyte (g /100 ml)
Cleaning of the instrument:
Cleaning of the cell:
[][]The cell must be cleaned after use. Thoroughly rinse the cell with the same solvent used for the sample, then rinse with purified water followed by methanol.
Cleaning of the sample compartment:
[][]The sample compartment should be cleaned immediately if anything is spilled into it in order to preserve the black matt finish and prevent corrosion or contamination.
[][]Use a soft cloth impregnated with a soapy solution to rub away any foreign material.
[][]Use a clean soft cloth dampened with water to rinse the cleaned surfaces thoroughly.
[][]Finally dry with a lint free cloth or tissue.
Calibration check with sucrose solution:
[][]Frequency: Yearly
[][]The check consists of determining the specific optical rotation of sucrose solution, using 20% w/v solutions. The method is detailed below. All results and calculations must be recorded on the calibration information sheet for Polarimeter.
Procedure:
Apparatus:
1dm Polarimeter tube.
Thermostat bath 20°C ± 0.2°C.
Reagent:
Sucrose Solution
Loss on Drying:
[][]Accurately weigh approximately 1g of sucrose into a clean dry weighing bottle that has previously been dried at 105°C, cooled in a dessicator for half an hour and weighed.
Dry in an oven at 105°C±2°C for 2 hours, then cool in a desiccator and reweigh.
[][]Calculate the loss in weight as a percentage and record the result on the polarimeter calibration check sheet using the following calculation:
LOD=Weight loss(g)/Weight taken(g)x100
Determination of Specific Optical Rotation at 20°C:
[][]Accurately weigh about 20 g of Sucrose into three separate 100 ml volumetric flasks. Dissolve in 80 ml of water and dilute to 100 ml with water.
[][]Zero the polarimeter using purified water in the 1dm polarimeter tube.
[][]Determine the optical rotation of each solution at 20°C ± 0.5°C in the 1dm tube.
[][]Record and calculate the results obtained for each solution on the polarimeter calibration check sheet using the following calculation:
A=αx100x100/I x c x(100-%LOD)
Where,
[α] = Specific Rotation at Temperature, 20°C and wavelength, 589.3 nm
A = Observed Rotation in degrees (°)
l = Path length in decimeters (dm)
c = Concentration of analyte (g/100 ml)
The specific optical rotation for each solution should be in the range +66.3° to +67.0° (reference the current European Pharmacopoeia).
Calibration check with Quartz Control Plate:
Frequency: Yearly
Apparatus:
Quartz Control Plate
[][]Check that the instrument and the Quartz Control Plate are at room temperature and that the instrument has been on for at least 10 minutes with the Quartz control Plate resting in the back of the sample chamber.
[][]Press Menu button to select Measurement Settings.
[][]Press Scale to select Optical Rotation.
[][]Press Temperature Correction and select Quartz.
[][]Press Statistics and select on (n-1).
[][]Press Exit button to return Manu.
[][]Press zero for zeroing the instrument.
[][]Place the Quartz Control Plate in to the sample chamber.
[][]Press Measure to measure the Quartz Control Plate.
[][]Type the Lot ID and press Enter.
[][]Type the Sample ID and press the Enter.
[][]Type the Sample Name and press the Enter.
[][]When the measurement completed press Print/Send key to print the measurement results.
[][]Remove the Quartz Control Plate form the chamber and return it to its container.
[][]Review the measurement results. Verify the Quartz Control Plate measure is within the tolerance specification.
Annexure:
[][]Annexure-I: Calibration Information Sheet for Polarimeter with Sucrose Solution
[][]Annexure-II: Calibration Information Sheet for Polarimeter with Quartz Control Plate
[][]Annexure-III: Log Book for Polarimeter