Polarimeter – Operation, Cleaning, Calibration SOP

Standard Operating Procedure (SOP) for Operation, Calibration, Cleaning and general maintenance of Jasco make Polarimeter instrument.

Procedure for Operation, Calibration, and Cleaning of Polarimeter

1.0   Purpose:

    • The purpose of this SOP is to describe the procedure for operation, cleaning, and calibration of the polarimeter.

2.0   Scope:

    • This SOP  is applicable to the polarimeter available in the Quality control laboratory at the pharmaceutical drug manufacturing plant.
    • Make: JascoJasco Polarimeter P2000
    • Model: P2000

3.0   References and Annexures:

    • References :

    • Operation manual supplied by the manufacturer
    • SOP for Instrument/Equipment usage log book.
    • Indian Pharmacopoeia Chapter-2.4.22
    • Annexures:

    • Annexure – 1: Format for Polarimeter calibration template ( by Quartz  plate )
    • Annexure – 2: Format for Polarimeter calibration template

4.0   Responsibilities – SOP for Polarimeter:

    • The Analyst shall be responsible for:

    • Operate the instrument as per SOP.
    • Calibrate the instrument as per SOP.
    • Maintain the calibration records.
    • Head QC or Designee shall be responsible for:

    • Check the SOP.
    • Impart the training to all concerned persons before the implementation of SOP.
    • Ensure that Operation & Calibration of the instrument is carried out as per SOP.
    • Execute the Out of Calibration (OOC) in case of calibration failure and breakdown and intimate the same to Quality Head.
    • Initiate repairs or breakdown and to make alternative arrangements during the status of under maintenance.
    • Ensure proper documentation as per SOP.
    • Quality Assurance shall be responsible for:

    • Check the SOP.
    • Ensure the implementation of the system as per SOP.
    • Quality Head shall be responsible for:

    • Review and approve the SOP.
    • Authorize the Out of Calibration investigation.
    • Ensure that the system is implemented.

5.0   Definition of terms & Abbreviations – SOP for Polarimeter:

    • Abbreviations:

    • SOP: Standard Operating Procedure
    • SOR: Specific Optical Rotation
    • OR: Optical Rotation
    • NIST: National Institute of Standards and Technology
    • PMT: Photomultiplier tubes
    • Definition of terms :

    • Optical Rotation :
    • The optical rotation of a substance or liquid is the angle through which the plane of polarization is rotated when polarized light passes through the substance or liquid/solution of the substance.
    • Such substances are said to be optically active.
    • If the plane of polarization is rotated to clockwise direction then it is called dextrorotatory (+) and if it is anticlockwise then called levorotatory (-).
    • Specific Optical Rotation (SOR) :

    • For solid samples :  
    • A specific optical rotation of a substance is defined as the angle of rotation of the plane of polarization at the wavelength of the D line of Sodium (λ=589.3 nm)measured at 25°C (unless otherwise specified)calculated with reference to a 1-dm thick layer of a solution containing1g of a substance per ml.
    •  For liquid sample: A specific optical rotation of a liquid substance is defined as the angle of rotation of the plane of polarization at the wave-length of the D line of sodium (λ=589.3 nm) measured at 25°C (unless otherwise specified), calculated with reference to a 1-dm thick layer of a solution and its density.

6.0   Procedure for Handling and Calibration of Polarimeter:

    • General Procedure – Polarimeter:

    • For the entry of usage of the instrument, follow the SOP on “Instrument/equipment usage logbook.
    • In case of any maintenance of the polarimeter instrument, follow SOP on “Maintenance of laboratory instrument.
    • Maintain the internal and third-party calibration schedule for the instrument as per SOP.
    • In case of noticing any calibration result out of the specified limit, follow the SOP of “Handling Out of Calibration.
    • Precautions during handling of Polarimeter:

    • Allow sufficient time to warm up the lamp before use
    • Optical rotation should be determined within 30 minutes of preparation, unless otherwise specified.
    • Maintain the required temperature during the optical rotation analysis.
    • Before start of the analysis this shall be conform that the instrument, and polarimeter tube is clean and no spillage or residues of the previous product, if present then need to clean.
    • Polarimeter tube should be clean with the diluent and then rinse with the small amount of sample.
    • Then fill it with the required solution in such a way that no air bubble remains in the path of polarized light.
    • Maintain the cleanliness of glass tube and avoid over-tightening of end screw caps.
    • Set the bubble at the center (curvature) to align the instrument properly.
    • The temperature probe shall keep clean after analysis to avoid the contamination which may affect the result.
    • Make sure that the sample chamber is empty and its lid is closed during the analysis and after completion of analysis.
    • The sample shall be measured using the same angular orientation of the cell as that of the blank.

    • While changing samples from one to another, wash the sample cell 2-3 times with the sample to remove any previous sample residue.
    • To hold the sample cell in the cell holder, set it in the same position facing the same direction. The data cannot be reproduced if the position/direction is changed.
    • Before shutting, make sure that the sample chamber is empty.
    • Turn OFF the power switch on the rear panel of the polarimeter.
    • Clean and air dry the sample cell for storage.
    • Allow sufficient time to warm up the lamp before use.
    • Maintain the required temperature during the optical rotation measurement of blank and sample solution.
    • Liquid and solutions of solids must be clear.
    • Cleaning procedure of Polarimeter:

    • The Analyst shall clean the Polarimeter and its surrounding with the dry cloth before and after use.
    • If the solution spills on the instrument then clean it immediately with the dry cloth.
    • If required clean the instrument with approved detergent (e.g. 1% Hemtop) followed by purified water and wipe with the dry cloth.
    • Lens cleaning shall be done by using lint-free tissue paper.
    • After every analysis cleaning of the glass tube and temperature probe shall be done by using the solvent in which the test solution prepared and then wash with purified water and finally rinse with methanol.
    • Operation Procedure of Jasco make Polarimeter:

    • Check the polarimeter calibration status of the instrument.
    • Press the power switch “ON” located on the front panel.
    • The power lamp located on the front right side of the instrument lights.
    • Now double click on the “Polarimeter” icon on the desktop.
    • Enter the user name and password and click on the login button.

Polarimeter - Login Page

    • After the login, click on the standard measurement option.
    • The system begins to initialize which requires about five minutes.
    • Click on the ‘parameter’ short cut or select it from the measure tab and enter the measurement parameters accordingly.
    • Enter the integration time in seconds.

    • If the time entered is 5 sec then the test shall be performed for 5 seconds.
    • Enter the repeat time by using the keyboard in numbers.
    • If the repeat time is given 5, then the instrument will perform the test 5 times.
    • Enter the interval time in seconds. If the time entered is 5 seconds then it will take 5 sec interval after every repeat reading.
    • Enter the cell length in mm.
    • The default value is 100 mm.
    • Enter the sample name, comment and save the parameter.
    • To zero set open the sample compartment and check that it is empty and then close it, select ‘zero clear’ from the measurement menu.
    • To take the blank reading, open the cover of the instrument.
    • Fill the blank (diluent) in the cell tube and hold the cell in the sample chamber by opening the lid of the instrument.
    • Dip the temperature sensor in the sample cell.

    • The temperature of sample or blank to be measured should be within the specified range, make sure that the mode is selected as ‘Optical rotation’ for ‘Blank’ in the parameters, click on the ‘Blank’ button and select ‘measure’.
    • For taking the measurement of the sample click on the parameters and select the mode as required, if Specific Optical Rotation (SOR), Concentration or Optical Rotation (OR) value is required then select accordingly and save the parameters.

Polarimeter - Parameter Setup

 

    • Click on the ‘Sample’ button and enter the sample name and comment if any, and select measure after the measurement is over, then save the data.
    • For printing the data, go to the ‘Spectra Manager CFR’ window and select ”Polarimeter Analysis’ on the left -hand side of the window.
    • Select the sample file by double-clicking on it, select print.
    • Filter Changing (Wavelength Set):

    • Normally, the Sodium (Na) lamp is used, the wavelength set (filter) is 589nm.
    • To check or change the wavelength, open the lid of the filter unit as shown in the figure below, to the left of the sample chamber.
    • Remove the filter (589nm) and place it safely.
    • Insert the filter having wavelength set 436nm to the filter unit.
    • In some cases, Use the Mercury (Hg) lamp as per the requirement of product.
    • The wavelength set (filter) required is 436nm.
    • To replace the wavelength set (filter) 436nm to wavelength set (filter) 589nm, follow the same procedure.
    • Light Source Change:

    • To change the light source select the ‘light source’ button on the standard measurement window.
    • Click on the Hg or the Na lamp with yellow mark first to deactivate the lamp and select the lamp which is required for analysis, the status of the lamp is indicated by the yellow color, the yellow color indicates that the lamp is activated.

Calibration Procedure of Polarimeter

    • Polarimeter Calibration Methods:

    • Calibration can be done either by preparing calibration solutions of sucrose/ fructose or by using Quartz plates.
    • Polarimeter Calibration frequency and standard :

    • Quarterly ± 7 days or immediately after maintenance.
    • Temperature sensor (If applicable) shall be calibrated yearly once with an accuracy of ± 0.5°C.
    • Calibration shall be carried out after the following maintenance.
      • Change in lamp
      • Replacement
    • Calibration shall be carried out after relocation
    • For the Calibration of Polarimeter, it is recommended to use the certified standard like sucrose and fructose.
    • Alternatively, Polarimeter Calibration can be checked by using a polarization reference standard which consists of a plate of quartz (This standard is available, traceable to NIST, from Rudolph research analytical or from Rudolph Instrument).
    • Polarimeter Calibration check using Quartz Plate :

    • Calibration with the Quartz Plate is done by mounting the quartz plate in a holder perpendicular to the light path.
    • Polarimeter Calibration shall meet the value supplied by the manufacturer(traceable to NIST) for that applicable wavelength.
    • The observations of calibration using quartz plate shall be recorded in Annexure-1
    • Polarimeter Calibration check using the Sucrose solution ( Dextrorotatory range)for Mercury and Sodium Lamp :

    • Frequency: Quarterly± 7 days
    • Follow the calibration procedure for Mercury (Hg) lamp having wavelength set (filter) 436nm as well as Sodium(Na) lamp having wavelength set (filter) 589nm.
    • The acceptance criteria for SOR at 20.0°C for Mercury lamp and 25.0°C for sodium lamp are mentioned in the Polarimeter calibration template as per Annexure-2.
    • Dry the sucrose at 105°C for 2 hours.
    • Prepare a series of solutions having the concentration of 10.0%, 20.0% 30.0%, 40.0% and 50.0% w/v solution of anhydrous sucrose in purified water as specified in calibration template i.e Annexure-2.
    • Condition the sucrose solutions and the blank solution (diluent) at 20°C±0.5°C while using Mercury (Hg) lamp
    • Condition the sucrose solutions and the blank solution (diluent) at 25°C±0.5°C while using Sodium (Na) lamp.
    • Take the reading of purified water (diluent) as a blank and auto-zero the instrument.

    • Fill the tube with the sample solution of the specified concentration of sucrose.
    • Measure the SOR of all five solutions using 1-dm Polarimeter tube, by following the operation procedure.
    • Take five readings of each solution. Each reading should meet the acceptance criteria as per the manufacturers COA
    • Tabulate the results in the Polarimeter calibration template.
    • Note 1: If the visual polarimeter is employed, the average of five determinations, corrected for the reading of the same tube with a solvent i.e. purified water, is used.
    • Note 2: If the automatic polarimeter is employed then blank to be performed before sample analysis, to avoid the interference of blank in the sample result.
    • Plot a linearity curve of component concentration vs corresponding optical rotation. The coefficient of correlation shall be not less than 0.992.
    • Polarimeter Calibration check using Fructose solution (Levorotatory range) for Mercury and Sodium Lamp:

    • Frequency: Quarterly ± 7 days
    • Note: If the location does not have any sample with the specification in the Levorotatory range then calibration in the Levorotatory range is not required to be performed.
    • Follow the calibration procedure for Mercury (Hg) lamp having wavelength set (filter) 436nm as well as Sodium(Na) lamp having wavelength set (filter) 589nm.
    • The acceptance criteria for SOR at 20.0°C for Mercury lamp and 25.0°C for sodium lamp shall be as per manufacturer COA.
    • Polarimeter Calibration shall be performed as per Annexure-2.
    • In-general the observed optical rotation at 436 nm is about double that at 589 nm (Ref. USP <781> ).
    • Dry about 5 gm of Fructose in the vacuum oven at 70°C for 4 hours.
    • Solution Preparation for Polarimeter Calibration:

    • 10% w/v Fructose Solution: Weigh accurately (5gm, it should be as accurate as possible) of previously dried fructose and transfer it in a clean and dry 50 ml volumetric flask, dissolve it in 25 ml of purified water.
    • Make up the volume (50 ml) with purified water.
    • Follow the above calibration steps with fructose solution.
    • Re-calibration of Polarimeter:
    • If the equipment is subjected to severe mechanical shock or vibration.
    • If the equipment is relocated.
    • When there is any suspicion about the accuracy of the numbers measured when any of the optical components like bulb, PMT, filter, polarizer or analyzer shall be changed or replaced.

ANNEXURE 1

Format for Polarimeter Calibration Template (by Quartz Plate)

Instrument Name Template Issuance No.
ID No. Make /Model
Location Calibration frequency Quarterly ± 7 days
Calibrated on Next calibration due on

 

TABLE -A

Quartz Rotatory Plate ( Dextro rotatory range ) Make/ Model :
Sr. No. Temperature Wavelength Actual Value Observed Value Acceptance Range (Actual value ± 0.5 %)
1 589 nm
2 436 nm

 

TABLE -B

Quartz Rotatory Plate ( Levo rotatory range ) Make/ Model :
Temperature Wavelength Actual Value Observed Value Acceptance Range (Actual value ± 0.5 %)
589 nm
436 nm

 

(Note :- The Limits shall be as per the calibration certificate provided by the manufacturer.)

Remarks: The instrument is calibrated & qualified/ Out of calibration & not qualified for use.

Calibration type: Scheduled / Not scheduled (Reason: _________________________)

Calibrated by: Checked by:
Date: Date:

 

ANNEXURE 2

Format for Polarimeter Calibration Template (Chemical Test)

Instrument Name Template Issuance No.
ID No. Make /Model
Location Calibration frequency Quarterly ± 7 days
Calibrated on Next calibration due on

 

Mercury Lamp : By Sucrose Solution (Dextro-rotatory range)

    • Calibration Requirements:-

    • Lamp used _________ Mercury (Hg)
    • Filter (wavelength set) used ______________ 436 nm
    • Analytical Balance Code No.______________ Valid upto _________
    • Vacuum Oven Code No.______________ Valid upto _________

Chemicals

Batch No. Cal.Std.No. Make/Grade Use Before
Sucrose anhydrous

    • Procedure – Polarimeter Calibration:

    • Sucrose Solution Preparation:
    • Take the required quantity of ____________________________ sucrose anhydrous and dry it in an oven at ___________ 105°C for _________ 2 hours.(From ________ to ________ ).
    • Prepare a series of solutions having the concentration of 10.0%, 20.0%, 30.0%, 40.0% and 50.0% w/v solutions of sucrose in purified water as specified below:
    • 10% w/v Sucrose Solution:
    • Weigh accurately _________ 5.000gm (as accurate as possible) of ___________________ previously dried sucrose and transfer it in cleanand dry _________ 50 ml volumetric flask.
    • Dissolve it in 25ml of __________ purified water and dilute up to the volume with _________ purified water.
    • 20% w/v Sucrose Solution:
    • Weigh accurately _________ 10.000gm (as accurate as possible) of ___________________ previously dried sucrose and transfer it in clean and dry _________ 50 ml volumetric flask.
    • Dissolve it in 25ml of __________ purified water and dilute up to the volume with _________ purified water.
    • 30% w/v Sucrose Solution:
    • Weigh accurately _________ 15.000gm (as accurate as possible) of ___________________ previously dried sucrose and transfer it in clean and dry _________ 50 ml volumetric flask.
    • Dissolve it in 25ml of __________ purified water and dilute up to the volume with _________ purified water.
    • 40% w/v Sucrose Solution:
    • Weigh accurately _________ 20.000gm (as accurate as possible) of ___________________ previously dried sucrose and transfer it in clean and dry _________ 50 ml volumetric flask.
    • Dissolve it in 25ml of __________ purified water and dilute up to the volume with _________ purified water.
    • 50% w/v Sucrose Solution:
    • Weigh accurately _________ 25.000gm (as accurate as possible) of ___________________ previously dried sucrose and transfer it in clean and dry _________ 50 ml volumetric flask.
    • Dissolve it in 25ml of __________ purified water and dilute up to the volume with _________ purified water.
    • Measurement – Polarimeter Calibration:

    • Condition the sucrose solutions and the blank solution (diluent) (________________ purified water) at ____________ 20°C±0.5°C.
    • Take the reading of ____________________ purified water (diluent) as a blank and make it to auto zero.
    • Take the readings of all samples within 30 minutes of sample preparation.

Sodium Lamp : By Sucrose Solution

    • Calibration Requirements:
    • Lamp used _________ Sodium (Na)
    • Filter (wavelength set) used ______________ 589 nm
    • Analytical Balance Code No.______________ Valid upto _________
    • Vacuum Oven Code No.______________ Valid upto _________
Chemicals Batch No. Cal.Std.No. Make/Grade Use Before
Sucrose anhydrous
    • Procedure for Polarimeter Calibration:

    • Sucrose Solution Preparation:
    • Take the required quantity of ____________________________ sucrose anhydrous and dry it in an oven at ___________ 105°C for _________ 2 hours (From ________ to ________ ).
    • Prepare a series of solution having the concentration of 10.0%, 20.0% , 30.0%,40.0% and 50.0% w/v solutions of sucrose in purified water as specified below:
    • 10% w/v Sucrose Solution:
    • Weigh accurately _________ 5.000gm (as accurate as possible) of ___________________ previously dried sucrose and transfer it in cleanand dry _________ 50 ml volumetric flask.
    • Dissolve it in 25ml of __________ purified water and dilute up to the volume with _________ purified water.
    • 20% w/v Sucrose Solution:
    • Weigh accurately _________ 10.000gm (as accurate as possible) of ___________________ previously dried sucrose and transfer it in clean and dry _________ 50 ml volumetric flask.
    • Dissolve it in 25ml of __________ purified water and dilute up to the volume with _________ purified water.
    • 30% w/v Sucrose Solution:
    • Weigh accurately _________ 15.000gm (as accurate as possible) of ___________________ previously dried sucrose and transfer it in clean and dry _________ 50 ml volumetric flask.
    • Dissolve it in 25ml of __________ purified water and dilute up to the volume with _________ purified water
    • 40% w/v Sucrose Solution:
    • Weigh accurately _________ 20.000gm (as accurate as possible) of ___________________ previously dried sucrose and transfer it in clean and dry _________ 50 ml volumetric flask.
    • Dissolve it in 25ml of __________ purified water and dilute up to the volume with _________ purified water.
    • 50% w/v Sucrose Solution:
    • Weigh accurately _________ 25.000gm (as accurate as possible) of ___________________ previously dried sucrose and transfer it in clean and dry _________ 50 ml volumetric flask.
    • Dissolve it in 25ml of __________ purified water and dilute up to the volume with _________ purified water.
    • Measurement – Polarimeter Calibration:

    • Condition the sucrose solutions and the blank solution (diluent) (________________ purified water) at ____________ 25°C±0.5°C.
    • Take the reading of ____________________ purified water (diluent) as a blank and make it to auto zero.
    • Take the readings of all sucrose solution within 30 minutes of sample preparation.    
    • Fill the tube with the sample solution of the specified concentrations of sucrose respectively.
    • Measure the Specific optical rotation of all five solutions using 1-dm Polarimeter tube.
    • Take ________ five readings of each solution.
    • Each reading should meet the acceptance criteria as specified in the observation table.
    • Tabulate the results in the observation table.
    • Plot a linearity curve of component concentration vs corresponding optical rotation.
    • The coefficient of correlation shall be not less than 0.992.

Sr. No.

Concentration of Sucrose (dried) (in %) Specific Optical Rotation at 25 °C ± 0.5°C Specific Optical Rotation, SOR (in %) at 25°C Correlation of coefficient (NLT 0.992)
Lamp  ______

            Sodium

Filter _________

              589nm

1 2 3 4 5 Mean SOR (in %)
1 10 +66.15° to +67.15°
2 20 +66.03° to +67.03°
3 30 +65.93° to +66.93°
4 40 +65.83° to +66.83°
5 50 +65.73° to +66.73°

 

Remarks: The instrument is calibrated & qualified/ Out of calibration & not qualified for use.

Calibration type: Scheduled / Not scheduled (Reason: _________________________)

 

Calibrated by: Checked by:
Date: Date:

Attachments (if any) :-

Mercury Lamp : By Fructose Solution

    • Calibration Requirements:
    • Lamp used _________ Mercury (Hg)
    • Filter (wavelength set) used ______________ 436 nm
    • Analytical Balance Code No______________ Valid upto _________
    • Vacuum Oven Code No______________ Valid upto _________
Chemicals Batch No. Cal.Std.No. Make/Grade Use Before
Fructose
    • Procedure for Polarimeter Calibration:

    • Fructose Solution Preparation:
    • Take the required quantity of ____________________________ fructose and  dry it in a vacuum oven at ___________ 70ºC for _________ 4 hours. (From ________ to ________ ).
    • 10% w/v Fructose Solution:
    • Weigh accurately _________ 5.000 gm (as accurate as possible) of ___________________ previously dried fructose and transfer it in cleanand dry _________ 50 ml volumetric flask.
    • Dissolve it in 25ml of __________ purified water and dilute up to the volume with _________ purified water.
    • Measurements – Polarimeter Calibration :

    • Condition the fructose solution and the blank solution (diluent) (________________ purified water) at ____________ 20°C±0.5°C.
    • Take the reading of ____________________ purified water (diluent) as a blank and make it to auto zero.
    • Fill the tube with the fructose solution of the specified concentration of fructose.
    • Measure the Specific optical rotation of the solution using 1-dm Polarimeter tube.
    • Take ________ five readings of solution.
    • Reading should meet the acceptance criteria as specified in the observation table.
    • Tabulate the results in the observation table.

Observation Table : Polarimeter Calibration

Sr. No.

 

Concentration of

Sucrose (dried) (in %)

 

Specific Optical Rotation at 20 °C ± 0.5°C Specific Optical Rotation, SOR (in %) at 20°C
Lamp _________

Mercury

Filter _________

436 nm

1 2 3 4 5 Mean SOR (in %)

 

1 10

 

Note:- The limits shall be as per the COA provided by the manufacturer.

Remarks: The instrument is calibrated & qualified/ Out of calibration & not qualified for use.

Calibration type: Scheduled / Not scheduled (Reason: _________________________)

Calibrated by: Checked by:
Date: Date:

 

Attachments (if any) :-

Sodium Lamp : By Fructose Solution

    • Calibration Requirements – Polarimeter:
    • Lamp used _________ Sodium (Na)
    • Filter (wavelength set) used ______________ 589 nm
    • Analytical Balance Code No.______________ Valid upto _________
    • Vacuum Oven Code No.______________ Valid upto _________

 

Chemicals Batch No. Cal.Std.No. Make/Grade Use Before
Fructose

 

    • Procedure for Polarimeter Calibration:

    • Fructose Solution Preparation:
    • Take the required quantity of ____________________________ fructose and dry it in a vacuum oven at ___________ 70ºC for _________ 4 hours. (From ________ to ________ ).
    • 10% w/v Fructose Solution:
    • Weigh accurately _________ 5.000 gm (as accurate as possible) of ___________________ previously dried fructose and transfer it in cleanand dry _________ 50 ml volumetric flask.
    • Dissolve it in 25ml of __________ purified water and dilute up to the volume with _________ purified water.
    • Measurement – Polarimeter Calibration:

    • Condition the fructose solution and the blank solution (diluent) (________________ purified water) at ____________ 25°C±0.5°C.
    • Take the reading of ____________________ purified water (diluent) as a blank and make it to auto zero.
    • Fill the tube with the sample solution of the specified concentration of fructose.
    • Measure the Specific optical rotation of the solution using 1-dm Polarimeter tube.
    • Take ________ five readings of solution.
    • Reading should meet the acceptance criteria as specified in the observation table
    • Tabulate the results in the observation table.

Sr. No.

 

Concentration of

Sucrose (dried) (in %)

 

Specific Optical Rotation at 25°C ± 0.5°C Specific Optical Rotation, SOR (in %) at 25°C

 

Lamp ____________

                   Sodium

Filter _________

                589 nm

1

2 3 4

5

Mean SOR (in %)

 

1 10  

 

 

Note :- The limits shall be as per the COA provided by the manufacturer.

Remarks: The instrument is calibrated & qualified/ Out of calibration & not qualified for use.

Calibration type: Scheduled / Not scheduled (Reason: _________________________)

Calibrated by: Checked by:
Date: Date:

 

Attachments (if any) :-

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Niranjan Singh is experienced in Pharmaceuticals, author and founder of Pharma Beginners, an updated pharmaceutical blogging platform. Email: [email protected]

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