Lyophlization & Elutriation

This will provide you a brief introduction to the two most important procedures in industry for preparation of different types of drugs and will definitely help you understand these processes. Thankyou !

1. LYOPHLIZATION & ELUTRIATION Presented to: Ma’am Ayesha Mehmood

2. LYOPHLIZATION

3. LYOPHLIZATION Definition: Lyophilization  or freeze drying is a process in which water is removed from a product after it is frozen and placed under a vacuum, allowing the ice to change directly from solid to vapor without passing through a liquid phase

4. PRINCIPLE OF LYOPHLIZATION Lyophilization is based on a simple principle of physics called “SUBLIMATION”. Sublimation is the process of transition of a substance from solid to the vapor state without passing through an intermediate liquid phase. Lyophilization is performed at temperature and pressure conditions below the triple point, to enable sublimation of ice. The entire process is performed at low temperature and pressure by applying vacuum, hence it is good for thermolabile compounds.

5. SIGNIFICANCE To preserve the Biological activity of product. To reduce the product weight so that transport cost can be reduced. To extend the shelf life or stability. To dry thermolabile materials. To eliminate the need for refrigerated storage. To get accurate, sterile dosing into the final product container.

6. STEPS IN LYOPHLIZATION

7. Freezing stage Freezing of product solution to a temperature below its eutectic temperature. Decrease the shelf temperature to -50ᵒc. Low temperature and low atmospheric pressure is maintained. Freons are used as refrigerant. Formation of ice crystals occur. The rate of ice crystallization define the freezing process and efficiency of primary drying .

8. PRIMARY DRYING Heat is introduced from shelf to the product under graded control by electrical resistance coils or circulating silicon's. The temperature and pressure should be below triple point of water i.e., 0.0098 ᵒc and 4.58mmHg. The driving force is vapor pressure difference between the evaporating surface and condenser Easily removes water up to 98% to 99%.

9. SECONDARY DRYING The temperature is raised to 50 - 60ᵒc and vacuum is lowered about 50 mmHg. Bound water is removed. Rate of drying is low. It takes about 10-20 hours.

10. PACKING After drying the vacuum is replaced by filtered dry air or nitrogen to maintain atmospheric pressure. Ampoules are sealed by either tip sealing or pull sealing method. Vials and bottles are sealed with rubber closures and aluminum caps.

11. FACTORS AFEECTING The factors affecting the process of lyophilization are the following: Sample size. Surface area. Thickness. Eutectic temperature. Solute concentration. Condenser temperature. Vacuum.

12. APPLICATIONS In pharmaceutical industry to increase shelf life. In food industry to preserve food and as an essences. In technical industries in chemical synthesis and formation of stable products. Flora and Fauna preservation.

13. ELUTRIATION

14. ELUTRIATION Definition: Elutriation is a process for separating particles based on their size, shape and density, using a stream of gas or liquid flowing in a direction usually opposite to the direction of sedimentation.

15. Explanation In other words, small size particles will move upward and large size particle will move downward. So basically it is a process of separation of fine particles from coarse particles. The particle size can also be measured by this process .

16. SIGNIFICANCE It appears more attractive than decantation and also has a certain practical advantages in that the volume changes need no operator attention. This allows a clear solution, or the filtrate to pass through and flow out of the container.

17. TYPES OF ELUTRIATIONS Gravitational Elutriation: It is a type of elutriation in which the fluid particles move downwards due to sedimentation (force of gravity) while the lighter particles remain upward. Centrifugal Elutriation: The one in which the fluid stream to rotate under high centrifugal force to suspend the particles. These particle which are too large to rotate with direction of fluid, separates out on the wall of elutriator. However, the fine particles move easily with the direction of fluid.

18. FACTORS AFFECTING ELUTRIATION The factors affecting the process of elutriation are as following: Velocity of fluid. Particle size. Position of particle. Density of particle.

19. APPLICATIONS Heavy and light Kaolin can be separated by this process.