SUBJECT NAME

SUBJECT NAME:Pharmaceutical Unit Operations - II SISP

EXPERIMENT NO: 04

NO.4 Evaluation of Stability by Centrifugation

Aim: To study the influence of centrifugal effect in separating the oil phase of freshly prepared turpentine liniment emulsion I.P.Requirements: Turpentine, liniment emulsion, centrifuge with graduated tubes, beakers, stirrer, measuring cylinder and balance.Principle: Centrifugal force is used to provide the driving force for the separation. Centrifugation is particularly useful when separation by ordinary filtration is difficult. For example separating highly viscous mixtures and colloidal dispersions in which difference in the densities is less. Centrifugation provides a convenient method of separating either 2 immiscible liquids or solids from a liquid. In this experiment turpentine liniment is subjected to centrifugal force into a centrifuge operated at a speed of 4000 rpm for 80 minutes. Percent oil separated is calculated for every 5 minutes in both the cases, with the data obtained graphs are plotted by taking centrifugation time versus percent volume of turpentine oil separated.Theory:Centrifugation is a unit process employed for separating the constituents present in dispersion with the aid of centrifugal force. The equipment in which centrifugal force is implied on dispersion is called centrifuge.

r

m

F

Separating power of a centrifuge is expressed as centrifugal force effect. It is a ratio of centrifugal force to gravitational force. Centrifugal effect can be calculated by using the following equation.Centrifugal effect = 2.013 dm2Diagram:

Procedure: Preparation of turpentine liniment:1. Soft soap was transferred into a motor and add few ml of water and resulting mixture was triturated.2. In another beaker required quantity of camphor was dissolved in turpentine oil.3. This solution was transferred into motor with continuous trituration until a soft cream is formed then it was transferred to a measuring cylinder and made up to a level with required number of water.Step 2:1. The calculated centrifuge tubes are cleaned labeled and filled with turpentine liniment up to the 10 ml mark.2. The tubes are placed in the basket, the centrifuge is switched on.3. The centrifuge is allowed to exert centrifugal effect on the emulsion for 5 minutes.4. After 5 minutes the speed controlled knobs is turned anti clock wise for 4 position to 0 position, when a setar has came to the centrifuge and the centrifuge tubes are taken out.5. The volume of turpentine oil separated which is present as a lower tube is noted as regarded.6. Without disturbing the tubes are placed back into the basket.7. This is repeated for 30 minutes with 5 minutes time interval and all the readings were tabulated.8. A graph is plotted by taking centrifugation time on x- axis and percent volume of turpentine oil separated on y- axis.Applications:1. Evaluation of suspensions and emulsions.2. Determination of molecular weight of colloids.3. Production of biological products.4. Production of bulk drug.5. Biopharmaceutical analysis of drugs.Graph:Graph is plotted by taking centrifugation time on x- axis and percent volume of turpentine oil separated on y- axis Report:The volume of turpentine oil separated _____________ with _____________in centrifugation time.TableS no.Ingredients Quantity for 100 mlPurpose

1Potassium hydroxide5.25 gmEmulsifying agent

Arachis oil20 ml

Oleic acid5 ml

2Camphor5 gmAnti microbial

3Turpentine oil65 mlCounter irritant

4Purified waterUp to 100 mlVehicle

Separation of Oil from Emulsion with 4000 RpmS no.

Time of centrifugation(min)Volume of turpentine oil separated (ml)Average volume (x)% oil separated= x100/total volume of emulsion

Centrifuge tube (A)Centrifuge tube (B)Centrifuge tube (C)Centrifuge tube (D)

10

21.2 ml

31.4 ml

41.5 ml

51.9 ml

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EXPERIMENT NO: 05

NO.5 Construction of Drying Rate Curve of CaCO3 Using Tray Dryer

Aim: To construct the drying rate curve of CaCO3 using tray dryer.Requirements: Dryer, stainless steel plate, beaker, balance and CaCO3.

Theory:Drying is defined as removal of small amount of water or other liquid from a material by the application of heat. Drying involves both heat and mass transfer operations. Heat must be transferred to the material to be dried in order to supply the latent heat required for vaporization of moisture. Mass transfer involves the depletion of water through the material to the evaporating surface and subsequent evaporation of water from the surface.

Water content- equilibrium relationship In wet solid mass water will be present as bound and unbound water. Bound water is the minimum water held by the material that exerts on equilibrium vapor pressure less than the pure water at the same temperature.Unbound water is the amount of water held by the material that exerts an equilibrium vapor pressure equal to that of the pure water at the same temperature.Equilibrium relationships:Air of constant temperature and humidity is passed over the wet solid. After a long exposure equilibrium of the process will be attained. Further exposure will not alter moisture content in the solid. At this stage vapor pressure of wet solid is equal to that of the surrounding atmosphere. Hence there is no drying or mass transfer. Based on the moisture content present in the sample several terms are expressed. Equilibrium moisture content is the amount of water present in the solid that exerts vapor pressure equal to that of vapor pressure of atmosphere surrounding it.Free moisture content is the amount of water i.e. free to evaporate from the solid surface.FMC= total water content EMC.Principle: Rate relationship can be studied considering simple model, which we mimic the conditions of a dryer. In this model the wet slab of material of sufficiently high moisture content is placed in the tray whose sides and bottoms are insulated the air is blown over the solid under constant drying conditions. The superficial water diffuses through the surrounding stationary air film and is carried away rapidly by the moving air stream, then water diffuses from interior of the solid to the surface. This process continues until pond water gets evaporated. Then the material attains equilibrium moisture content.The rate of drying can be determined by periodically weighing CaCO3 slurry. The difference in the weights of two successive weights gives the loss of moisture content i.e. amount dried. The following equation is used to calculate the rate of drying.

Procedure: Preparation of turpentine liniment:4. Soft soap was transferred into a motor and add few ml of water and resulting mixture was triturated.5. In another beaker required quantity of camphor was dissolved in turpentine oil.6. This solution was transferred into motor with continuous trituration until a soft cream is formed then it was transferred to a measuring cylinder and made up to a level with required number of water.Step 2:9. The calculated centrifuge tubes are cleaned labeled and filled with turpentine liniment up to the 10 ml mark.10. The tubes are placed in the basket, the centrifuge is switched on.11. The centrifuge is allowed to exert centrifugal effect on the emulsion for 5 minutes.12. After 5 minutes the speed controlled knobs is turned anti clock wise for 4 position to 0 position, when a setar has came to the centrifuge and the centrifuge tubes are taken out.13. The volume of turpentine oil separated which is present as a lower tube is noted as regarded.14. Without disturbing the tubes are placed back into the basket.15. This is repeated for 30 minutes with 5 minutes time interval and all the readings were tabulated.16. A graph is plotted by taking centrifugation time on x- axis and percent volume of turpentine oil separated on y- axis.Applications:6. Evaluation of suspensions and emulsions.7. Determination of molecular weight of colloids.8. Production of biological products.9. Production of bulk drug.10. Biopharmaceutical analysis of drugs. Report:The volume of turpentine oil separated _____________ with _____________in centrifugation time.

TableS no.Ingredients Quantity for 100 mlPurpose

1Potassium hydroxide5.25 gmEmulsifying agent

Arachis oil20 ml

Oleic acid5 ml

2Camphor5 gmAnti microbial

3Turpentine oil65 mlCounter irritant

4Purified waterUp to 100 mlVehicle

Separation of Oil from Emulsion with 4000 Rpm

S no.

Time of centrifugation(min)Volume of turpentine oil separated (ml)Average volume (x)% oil separated= x100/total volume of emulsion

Centrifuge tube (A)Centrifuge tube (B)Centrifuge tube (C)Centrifuge tube (D)

10

21.2 ml

31.4 ml

41.5 ml

51.9 ml

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