SOP on Operation of Colloid Mill

The purpose of this standard Operating Procedure (SOP) is to lay down a procedure for operation of colloid mill.

This procedure is applicable to operation of colloid mill at manufacturing facility of Pharmaceutical Industry.

    • Ensure that area is cleaned as per SOP.
    • Ensure that all the parts of colloid mill are cleaned as per SOP.
    • Ensure mains are ‘OFF’ and plug top is removed from socket.
    • Diagram:
  • Check that screws on rotor (3 in No.) are properly fitted.
    • Rotate the rotor by hand and ensure free movement.
    • Place the outer ring and turn it clockwise to match scale with indicator mark (scale to be set as per product requirement).
    • Tighten the handles on the sides so that ring is locked in position.
    • Place the neoprene food grade gaskets followed by top ring and hopper.
    • Tighten the bolts of hopper.
    • Put ‘ON’ the mains and check direction of rotation (direction of rotation should be long the arrow marked on the body of the machine).
    • Fix the recirculation/outlets nozzle along with gasket.
    • Take the line clearance as per SOP and record the line clearance activity in Annexure.
    • Take a trial with purified water.
    • Ensure absence of leakage or abnormal noise. Affix ‘USE FOR’ label on machine with product name, date and sign of production officer.
    • Feed the solution/suspension to be milled in hopper and switch ‘ON’ the Colloid mill.
    • Mill the solution/suspension in single pass or multiple pass (recirculation) by adjusting the knob   on the outlet nozzle (as per product requirement). Check the grittiness of out coming suspension.
    • Rinse the colloid mill with solvent/purified water.
    • Switch ‘OFF’ the colloid mill.
    • Affix ‘TO BE CLEANED’ label on the hopper with Equipment no., previous product, Batch No., Date, and Signature of production officer.
    • Record cleaning activity as per SOP in Cleaning and Usage Log of Equipment and Area.
    • Calibration :
      • RPM of colloid mill every 12 months by outside party.
      • Frequency every 12 months.

NOTE:      1.    Colloid Mill Should Be Cleaned Immediately After Use.

                   2.    Set The Colloid Mill At ‘0’.

                   3.   If Colloid Mill produces any abnormal noise should be reported to

                         Engineering department immediately.

                   4.   Never live machine with material overnight.

                  5.   Check the direction of rotation of the rotor before starting of the

                         machine. ‘Direction of rotation of the mill must be clockwise’.


As per Employee training SOP


As per SOP for SOP



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