What are the two main steps in drying of materials?

What are the two main steps in drying of materials?
by

1 Answer

Answer :

Drying process involves both heat transfer and mass transfer.

The steps needed for drying are;

i.Heat must be supplied to provide latent heat of vaporization.

ii.The liberated vapour must be removed by moving an air stream.
by

Related questions

Define drying. Give application of drying in pharmacy.

Description : Define drying. Give application of drying in pharmacy.

Last Answer : Definition:  Drying: It is defined as final removal of liquid from solid by vaporization with aid of heat. Application:  1) In pharmaceutical industry it is used as a unit process in the ... of product, when powder is dried it gets solublised fast. 7) Drying ensures free flowing of powders.

List any four equipment used in drying.

Description : List any four equipment used in drying.

Last Answer : Equipment used for drying: i) Tray dryer ii) Tunnel dryer iii) Rotary dryer iv) Fluidized Bed Dryer v)Vacuum dryer vi) Freeze dryer.

Explain The theory of freeze drying and state its application.

Description : Explain The theory of freeze drying and state its application.

Last Answer : Theory:-  i) In this process, the material is frozen in a suitable container connected to a high vacuum system, so that the vapour pressure of water vapours is ... antibiotics, blood products, vaccines, enzymes preparation, microbiological cultures & other thermo labile pharmaceutical substances.

Explain principle of freeze drying. Give its advantages.

Description : Explain principle of freeze drying. Give its advantages.

Last Answer : Principle:  i. The material is frozen in a suitable container connected to a high vacuum system, so that the vapour pressure of water is reduced to less than that of material being dried. ii. ... it is properly sealed in an inert atmosphere. vii. The sterility of the product can be maintained. 

Define Drying .What are different factors affecting to the rate of drying?

Description : Define Drying .What are different factors affecting to the rate of drying?

Last Answer : Definition: Final removal of liquid from the solid with the help of heat is called drying. Factor affecting the rate of drying: Following factor can affect the rate of drying: 1) Surface area of ... (Hs-Hg) between surface layer and atmospheric: if difference is more rate of drying will be fast.

Give application of freeze drying.

Description : Give application of freeze drying.

Last Answer : (i) The process is mainly used for drying of biological products such as antibiotics, blood products, vaccines ,enzymes preparation, microbiological cultures etc. (ii) The heat sensitive material can be dried

Discuss the theory, construction, and working of freeze drying apparatus

Description : Discuss the theory, construction, and working of freeze drying apparatus

Last Answer : Theory: Freeze drying or sublimation drying consists of simply reducing the temperature & pressure to values below the triple point .(4.579mm of Hg& temp. of 0.0099 c) Under these ... . 5. Packing: Biological products are dried packed in aseptic condition immediately after drying.

Discuss in brief Freeze drying.

Description : Discuss in brief Freeze drying.

Last Answer : Principle:  The material is frozen in a suitable container connected to a high vacuum system, so that the vapour pressure of water is reduced to less than that of material being dried. Thus, it ... special precautions. 3. The period of drying is quite long.(usually not less than 10 hours)  

Write the applications of drying.

Description : Write the applications of drying.

Last Answer : i. It is used in manufacturing of granules. ii. It reduces the bulk and weight of the material. iii. It helps in preservation of crude drug. iv. It helps in size reduction of crude drug. v. It is used in the drying of aluminium hydroxide. vi. It controls the moisture level in solids.

Give Significance of drying.

Description : Give Significance of drying.

Last Answer : 1) In pharmaceutical industry it is used as a unit process in the manufacture of granules which can be dispensed in bulk or converted into tablets or capsules. 2) Drying can also be used to ... of product, when powder is dried it gets solubilised fast. 7) Drying ensures free flowing of powders.

Give steps involved in moist granulation.

Description : Give steps involved in moist granulation.

Last Answer : Steps: i. Moisten of Medicament with excipients with granulating agent. ii. Sieving of moist mass through sieve number 8 or 10. iii. Drying of wet granules in hot air oven at ... sieve number 20 to collect granules of uniform size v. Lubrication of sifted granules with lubricating agent

State and explain the steps involved in sugar coating of tablet.

Description : State and explain the steps involved in sugar coating of tablet.

Last Answer : Steps of sugar coating of tablet: Sieving Sealing Sub-coating Syrup coating Finishing Polishing i) Sieving :- The tablets to be coated are shaken in a suitable sieve to remove the fine ... on the canvas cloth. This gives a proper shining to the tablets Sugar coating is an art 

Explain the different steps involved in sugar coating of tablet.

Description : Explain the different steps involved in sugar coating of tablet.

Last Answer : Steps of sugar coating of tablet:-  Sieving Sealing Sub-coating Syrup coating Finishing Polishing i) Sieving :- The tablets to be coated are shaken in a suitable sieve to remove the ... the wax coated tablets are rubbed on the canvas cloth. This gives a proper shining to the tablets

What do you mean by reserved percolation? Enlist different steps involved in it.

Description : What do you mean by reserved percolation? Enlist different steps involved in it.

Last Answer : Reserve percolation:   In this process a part of percolate, generally 3/4th volume of the finished preparation is reserved.(contains high solute concentration) Then the percolation process is continued ... :  a. Imbibition, b. Maceration, c. Percolation, d. Distillation or evaporation.

List the steps involved in slugging process

Description : List the steps involved in slugging process

Last Answer : i) Sieving ii) Weighing iii) Blending iv) Slugging v) Screening vi) Blending vii) Compression Or. Drug + Excipients → Blending → Slugging(formation of big size tablet) → Screening → Blending → Compression.

Name any four materials used for packaging.

Description : Name any four materials used for packaging.

Last Answer : Types of materials used for packaging are: i) Glass ii) Plastic iii) Metal iv) Paper and board 

Materials used in pharmaceutical closures.

Description : Materials used in pharmaceutical closures.

Last Answer : Following are material used in pharmaceutical closures 1) Rubber Cork is obtained from the bark of oak tree. Cork is chemically inert and it does not impart any odour or flavour to ... of closure meant for vials, transfusion fluid bottles. Rubber, two types natural or synthetic, 

Define ‘Containers’. What are the basic materials used in making of container?

Description : Define ‘Containers’. What are the basic materials used in making of container?

Last Answer : Containers: A device that holds the drug and it may or may not be in direct contact with the pharmaceutical dosage form or preparations. Basic materials used in making of container: i)Glass ii) Plastic iii) Metal iv) Paper and board

Mention different types of closures. Comment on materials used for making closures.

Description : Mention different types of closures. Comment on materials used for making closures.

Last Answer : Types of closures with examples:  1. Plug type. 2. Crown cap. 3. Push-fit cap. 4. Screw closures. Materials used in pharmaceutical closures:   1) Rubber Cork is obtained ... the construction of closure meant for vials, transfusion fluid bottles. Rubber, two types natural or synthetic, 

Write the main objectives of mixing.

Description : Write the main objectives of mixing.

Last Answer : Objectives of mixing:  i. To form uniform mixture.  ii. To promote chemical reaction.  iii. Dispersion of solid particles in liquid.  iv. Dispersion of two immiscible liquids.

What are main objectives of mixing? Give the list of equipment’s used for mixing of semi solids.

Description : What are main objectives of mixing? Give the list of equipment’s used for mixing of semi solids.

Last Answer : Objectives of mixing are as follows: i) Simple physical mixing of materials to form a uniform mixture. ii) To promote the chemical reaction to get uniform product. iii) Dispersion of solid in ... Equipment's used for mixing of semi solids: Triple roller mill Agitator mixer. Planetary mixer

Define desiccation with two example of Desiccants and draw a diagram of “ Desiccator”

Description : Define desiccation with two example of Desiccants and draw a diagram of “ Desiccator”

Last Answer : Definition: Desiccation is the process of complete removal of mechanically admixed water from substances. Examples of desiccants:  Silica, activated charcoal, calcium sulfate, calcium chloride, and molecular sieves. Diagram:

List qualities of an ideal filter aid and state any two example of it.

Description : List qualities of an ideal filter aid and state any two example of it.

Last Answer : Ideal qualities of filter aid:  i. It should be remain suspended in the liquid. ii. It should be free from impurities. iii. It should be inert. iv. It should have a particle size distribution suitable ... i. Asbestos. ii. Cellulose. iii. Carbon. iv. Diatomaceous earth (silica). v. Perlite.

The comparison of bioavailability between two dosage forms is refereed as____________ A. Bioavailability B. Biopharmaceutics C. Biological D. Bioequivalence

Description : The comparison of bioavailability between two dosage forms is refereed as____________ A. Bioavailability B. Biopharmaceutics C. Biological D. Bioequivalence

Last Answer : D. Bioequivalence 

How will you separate two immiscible liquids in pharmacy? Draw a libelled sketch of the apparatus used in laboratory.

Description : How will you separate two immiscible liquids in pharmacy? Draw a libelled sketch of the apparatus used in laboratory. 

Last Answer : :Steam Distillation( immiscible liquids): In pair of immiscible liquids , each liquid exerts its own vapour pressure & neither liquid has any appreciable effect on the vapour pressure ... are not decomposed by water , this provides an alternative to distillation under reduced pressure  

Give any two applications of simple distillation.Describe method of separation of two immiscible liquids.

Description : Give any two applications of simple distillation.Describe method of separation of two immiscible liquids.

Last Answer : Applications of simple distillation(0.5 2) 1) Preparation of distilled water and water for injection. 2)Recovery of alcohol in preparation of dry extracts 3)Many volatile oils and ... proportion The distillate can be collected in Florentine receiver for separation of oil & water.

Explain the working of ball mill with a well labeled diagram and give any two advantages

Description : Explain the working of ball mill with a well labeled diagram and give any two advantages

Last Answer : Working:   The drug to be ground is put into the cylinder of the mill and is rotated. The speed of the rotation is very different. At low speed, the mass of balls will slide or roll over each other ... for batch as well as continuous grinding vi)can be used for dry as well as wet grinding.

Name any two polymers used for film and enteric coating.

Description : Name any two polymers used for film and enteric coating.

Last Answer : Film Coating. 1. Hydroxypropyl methyl cellulose. 2. Hydroxyethyl methyl cellulose. 3. Carbowax. 4. PEG-400 5. Ethyl cellulose Enteric coating: 1. Cellulose acetate phthalate. 2. Cellulose ... acetate succinate. 4. HPMC acetate succinate. 5. HPMC phthalate. 6. Polymethacrylate. 7. PVAP

Explain principle and working of fluid energy mill with a diagram.

Description : Explain principle and working of fluid energy mill with a diagram.

Last Answer : Principle  It works on the principle of impact and attrition. Working: The air or inert gas is introduced with a very high pressure through nozzles. Solids are introduced into air stream through inlet. ... 100 mesh and then passed through fluid energy mill. Diagram of fluid energy mill :

Give application of simple distillation. What is the principle of fractional distillation?

Description : Give application of simple distillation. What is the principle of fractional distillation?

Last Answer : Applications of simple distillation:  i. It is used for the preparation of distilled water and water for injection. ii. Preparation of many volatile oils and aromatic water. iii. Purification ... becomes richer with the liquid having the lower boiling point which gets condensed in a condenser. 

Mention official and unofficial evaluation test for tablets. Describe weight variation test.

Description : Mention official and unofficial evaluation test for tablets. Describe weight variation test. 

Last Answer : Official test list: 1. Size and shape of tablet. 2. Appearance. 3. Content of active ingredient. 4. Uniformity of weight/weight variation test 5. Uniformity of content 6. ... the percentage deviation given in the table and none should deviate by more than twice that percentage.

Draw a well labelled diagram of aerosol container and give its advantages and disadvantages.

Description : Draw a well labelled diagram of aerosol container and give its advantages and disadvantages.

Last Answer : Diagram of aerosol container Advantages:   1. Medicament can be delivered directly to affected areas. 2. Absence of air prevents oxidation. 3. Hydrolysis of medicament prevented ... on injured skin. 4. Difficulties occurred during formulation when drug not soluble in propellants.

Discuss working of ball mill with neat diagram.

Description : Discuss working of ball mill with neat diagram. 

Last Answer : Working: The drug to be ground is put into the cylinder of the mill and is rotated. The speed of the rotation is very different. At low speed, the mass of balls will slide or roll over each other and ... and passed through a sieve to get powder of the required size. Ball mill diagram:   

Define pharmaceutical container. Give qualities of an ideal container.

Description : Define pharmaceutical container. Give qualities of an ideal container.

Last Answer : Definition: Pharmaceutical container  A device that holds the drug and it may or may not be in direct contact with the pharmaceutical dosage form or preparations. Qualities of an ideal container:  1 ... and temperature. 7. Labelled easily 8. Non-toxic. 9. Closure easily removable/replaceable.

Write the official standards of powder.

Description : Write the official standards of powder.

Last Answer : i. Coarse powder: A powder of which all particles pass through sieve no 10 with nominal aperture size 1.7mm and not more than 40% pass through sieve no 44 with nominal aperture size 355um.  ii. ... powder: A powder of which all particles pass through sieve no 120 with nominal aperture size 125 um.

Write special application of capsule.

Description : Write special application of capsule. 

Last Answer : Applications of capsule:  1. Enteric coated capsule: These capsules do not disintegrate in stomach (Acidic Medium) but break up in intestine (Alkaline medium). On commercial scale, a coating ... gelatine commonly used Capsule punctured by using sterile needle and then instilled into the eye.

Give the principle and working of Fluidised bed dryer.

Description : Give the principle and working of Fluidised bed dryer.

Last Answer : Principle: In FBD, good contact between hot air and particles to be dried is obtained which cause rapid drying. Working of Fluidised bed dryer: Two types of FBD are used in pharmaceutical industry. There are ... ranging from 5 kg to 200 kg with an average drying time of about 20-40 min.

Define aseptic techniques. What are the various sources of contamination?

Description : Define aseptic techniques. What are the various sources of contamination?

Last Answer : Definition: Aseptic technique  The method which is used to prevent the access of microorganism during the preparation of parenteral product and their testing are called Aseptic Technique Sources of ... are also a source of contamination. A handkerchief is the richest source of contamination. 

Give principal and working of silverson homogenizer with labelled diagram.

Description : Give principal and working of silverson homogenizer with labelled diagram.

Last Answer : Principal:   These work on the principal of braking large globules in to small globules by passing them under pressure through a narrow orifice. Working:   The emulsified head is placed in the vessel ... blades. So a fine emulsion is produced which is then expelled out. Diagram :

Write the advantages and disadvantages of glass as a material for packaging. Merits of Glass container

Description : Write the advantages and disadvantages of glass as a material for packaging. Merits of Glass container

Last Answer : Economical. Available in variety of sizes and shapes.  Chemically inert, impermeable, strong and rigid. Does not deteriorate with age. Easy to label. Excellent barrier against light. ... easy to break. Heavy, Bulky to carry. Leaching and absorption of alkalis. Flak formation

Draw a well labelled diagram of filter candle. Give its working and disadvantages.

Description : Draw a well labelled diagram of filter candle. Give its working and disadvantages.

Last Answer : Diagram : Working  : The filter candle is placed in a vessel containing the liquid to be filtered. When vacuum is applied, the pressure inside the candle is decreased. Due to ... Disadvantages   1. Chance of clogging/blocking. 2. Traces of material may come in the solution.

Explain the factors affecting evaporation of a liquid.

Description : Explain the factors affecting evaporation of a liquid.

Last Answer : Factor affecting evaporation  1. Temperature: The rate of evaporation is directly proportional to the temperature of the liquid. The evaporation can be accelerated by increasing the temperature but it ... of evaporation is maximum at its boiling point when the liquid has maximum vapour pressure.

Write the working of filter press with well labelled diagram.

Description : Write the working of filter press with well labelled diagram.

Last Answer : Working:  1. The slurry is pumped in under positive pressure up to 20 bar and fill each frame. 2. The filtrate passes through the cloths on opposite sides of the frame and runs down between the ... 6. Thickness of cake can be varied by using frame of different thickness. Diagram: 

Explain in detail evaporating still with its advantage and disadvantages.

Description : Explain in detail evaporating still with its advantage and disadvantages.

Last Answer : It consist of a hemispherical pan made from copper or stainless steel. It is surrounded by a steam jacket. Still is covered from top and connected to condenser. Hemispherical shape ... heat transfer is poor. Heating surface is limited. Not suitable for thermolabile material.

Define sterilisation and classify methods of sterilisation.

Description : Define sterilisation and classify methods of sterilisation.

Last Answer : Definition: Sterilizations is the process of complete destruction of all microorganisms along with their spores present in the system.  Methods of sterilization:  I. Physical methods:  1. Dry heat ... . Seitz filters  3. Sintered glass filters 4. Sintered metal filters  5. Membrane filters

Define Pharmacopoeia. List official books used in India.

Description : Define Pharmacopoeia. List official books used in India. 

Last Answer : Defination: Pharmakon means a drug and poeia means to make . Pharmacopoeia is defined as a compressive book which is issued under the authority of government and contains a list of drug ...  v) International Pharmacopeia  vi) Japanese Pharmacopoeia (J.P.)  vii) Martindale Extra Pharmacopoeia 

Why injectables should not be stored in soda lime glass containers?

Description : Why injectables should not be stored in soda lime glass containers?

Last Answer : Soda lime glass container is not used for the storage of parenterals because: i. It yields an appreciable quantity of alkali to water. ii. Flakes separate comparatively easily. iii. On ... 's relatively high coefficient of expansion makes it liable to fracture with sudden changes of temperature. 

Define ‘menstruum’ and state three ideal qualities of a menstruum.

Description : Define ‘menstruum’ and state three ideal qualities of a menstruum.

Last Answer : Menstruum :- Solvent used to extract the drug.  Ideal properties of menstruum: i) Cheap. ii) Non-toxic. iii) Stable chemically and physically. iv) Selective i.e. remove the desired active constituents with minimum amount of inert materials.

Why are tablets coated ?

Description : Why are tablets coated ?

Last Answer : Reasons for coating of tablets: i. To mask the unpleasant taste and odour. ii. To improve the appearance of tablets. iii. To prevent the medicament from atmospheric effects. iv. To control the ... v. To produce the sustained release product. vi. To prevent the drug degradation in stomach pH.

Define ‘slurry’ and ‘filter cake’.

Description : Define ‘slurry’ and ‘filter cake’.

Last Answer : i) Slurry: Mixture of insoluble substances suspended in a liquid and intended to filter before use.   ii) Filter cake: The solid which gets collected on the filter is called as filter cake.