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    LYOPHILIZATION

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    1 : LYOPHILIZATION Muhammad Ijaz Ashraf M.Sc Chemistry. Manager Quality Control Lahore, Pakistan.
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    3 : Did the infidels not consider that the heavens and earth were closed up, then We opened them out? And We made every made living thing from water. Will they then believe? (Surah Al-Ambia - Ayat 30)
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    8 : WATER ?
    9 : LIFE 70% TO 90% COMPOSED OF WATER.
    10 : THERE ARE DIFFERENT CONCENTERATIONS OF WATER IN NATURAL PRODUCTS
    11 : SOLID (ICE) LIQUID (WATER) \ GAS (VAPOUR)
    12 : WATER IS IN LIQUID PHASE AT S.T.P. e.g.25•C and 1atm pressure.
    13 : LIQUID VAPOUR SOLID BOILING SUBLIMATION Melting
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    16 : WHAT IS LYOPHILIZATION?
    17 : LYO = Solvent PHILE = Loving
    18 : It is a DE-HYDRATION Process
    19 : Freezing the materials so that the water in the food become ice; Under a vacuum, sublimating the ice directly into water vapour; Drawing off the water vapour;
    20 : Typically used to preserve a perishable material or make the material more convenient for transport.
    21 : The process by which water is extracted from Pharmaceuticals food and other products.
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    23 : After the process successfully completed, product can be stored at room temperature.
    24 : ADVANTAGES
    25 : 1- To preserve the biological activity of a product. 2. To reduce the product weight to lower the transportation cost. 3. To extend the shelf-life or stability
    26 : 5. To dry heat sensitive materials. 6. To eliminate the need for refrigerated storage. 7. To get accurate, sterile dosing into the final product container.
    27 : 1- Maximize retention of Activity. 2- Optimized Shelf Life. 3- Rapid Re-constitution. 4- Consistent Finished Cake.
    28 : OTHER NAME ARE; Freeze-drying Process or Cryo - desiccation
    29 : MECHANISM: Freezing the material and then reducing the surrounding pressure and adding enough heat to allow the frozen water in the material to sublime directly from the solid phase to the gas phase.
    30 : STEPS IN THE LYOPHILIZATION: 1- Freezing (most critical phase) 2- Drying Primary Secondary
    31 : Freezing: In this phase, the drug material is frozen but SLOWLY to create the larger crystals. The temperature is maintained between -50° C and -80° C.
    32 : Primary drying: The water content is sublimate from the drug molecules. - Pressure is lowered with the increasing heat - The water is removed as vapor form. This process is slow because if heat is too much, it will alter the drug property or structure.
    33 : Secondary drying: If any unfrozen water content remains in the drug product, it will be removed in this step. Temperature is higher than the primary drying stage. Water content is removed (98%-99%) from the drug material which helps drug to maintain its stability.
    34 : Water content is removed (98%-99%) from the drug material which helps drug to maintain its stability.
    35 : This complex process require CAREFUL balancing of products , Equipment and processing technique. `
    36 : Usually, the freezing temperatures are between -50 °C and -80 °C
    37 : Cool the material below its TRIPLE POINT (0.0098°C) (The lowest temperature at which the solid and liquid phases of the material can coexist)
    38 : The freezing phase is the most critical in the whole freeze- drying process.
    39 : Because the product can be spoiled if badly done.
    40 : TYPES OF FREEZING: IN LABORATORY: SHELL FREEZERS ARE USED 1- DRY ICE IN METHANOL. 2- LIQUID NITROGEN
    41 : BUT ON LARGE SCALE, FREEZING MACHINES ARE USED.
    42 : PRIMARY DRYING ICE REMOVING PHASE
    43 : DONE BY SUBLIMATION
    44 : The process in which solid phase of the substance directly goes into Gaseous phase without going into the Liquid phase.
    45 : The temperature at which vapor pressure of a liquid becomes equal to the atmospheric pressure.
    46 : Vapor pressure of a liquid = Atmospheric pressure.
    47 : WATER BOILS AT ABOUT 98C IN MURRE BUT AT 100C IN KARACHI
    48 : LOWERING OF ATMOSPHERIC PRESSURE
    49 : Pressure is controlled through the application of partial vacuum
    50 : 95% OF WATER IS REMOVED IN THIS PHASE.
    51 : DURING THIS PHASE WATER VAPORS ARE PRODUCED IN HEAVY AMOUNT
    52 : About one millimeters of ice produces more than 1,000,000 ml of water vapors.
    53 : To handle it is usual to fit a refrigerated trap (called the ice condenser) between the lyophilization chamber and the vacuum pump.
    54 : EQUIPMENT
    55 : - SHELVES IN VACUUM CHAMBER - DRYING / FREEZING CHAMBER - VACUUM PUMP - REFRIGERATION UNIT
    56 : In vacuum chamber there are shelves capable of cooling by Cooling Elements
    57 : After Freezing, the vacuum pump evacuates the chamber and the product is heated.
    58 : EFFECT OF HEAT TRANSFER
    59 : THERE ARE THREE METHODS OF HEAT TRANSFER
    60 : CONDUCTION COVENTION RADIATION
    61 : IN CONDUCTION, HEAT IS TRANFERED FROM PARTICLE TO PARTICLE.
    62 : Heat is transferred by thermal conduction from the shelf, through the vial, and ultimately into the product.
    63 : The container in which a substance is lyophilized must 1- Permit thermal conductivity,
    64 : 2- Be capable of being tightly sealed at the end of the lyophilization cycle. 3- Minimize the amount of moisture to permeate its walls and seal.
    65 : Successful lyophilization is heavily dependent on good thermal conductivity.
    66 : Such containers should be made of a material having 1- Good thermal conductivity;
    67 : 2- Should provide good thermal contact with the lyophilizer shelf, which is the source of heat during processing.
    68 : 3- Should have a minimum of insulation separating the source of heat from the product requiring heating.
    69 : Poor thermal conductivity results from; 1- Shape of containers 2- Size of containers 3- Quality of containers
    70 : 4- Containers made of materials of low Co-efficient of Heat transfer.
    71 : 5- Thermal Barrier e.g. Excessive amount of material used that may act as insulator.
    72 : It prevents energy from being transferred to the point at which the frozen ice and dried product interface.
    73 : If ,due to Thermal Barriers, sublimation could not be controlled.
    74 : The portions of the chemicals may actually be vacuum-dried rather than freeze-dried.
    75 : SEALING OF LYOPHILIZED PRODUCT
    76 : This starts at the end of Lyophilization cycle
    77 : It should be done before the removal of TRAYS the Ultra dry atmosphere within the Lyophilizer.
    78 : If not properly done, you have to compromise; 1- Increased Shelf Life. 2- Enhanced chemical performance 3- Rapid Re-constitution.
    79 : If moisture re-enter the product then, 1- There will be Loss of product. 2- Product Failure in the market. 3- Re-call of the product.
    80 : YOUR SALARIES IN THE FORM OF FINE.
    81 : DISADVANTAGES
    82 : 1- High capital cost of the Equipment 2- High Energy costs 3- Long process Time
    83 : It should only be used when Product is; 1- Unstable. 2- Heat Liable
    84 : 3- Minimum particulate Required 4- Accurate dosing needed. 5- Complete rehydration is required
    85 : Product is of HIGH VALUE
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