Describe various factors affecting size reduction.

1 Answer

Answer :

i. Hardness: Soft material easy break than hard.

ii. Toughness: Drug with fibrous nature or those having high moisture content are tough and hard to reduce in size.

iii. Stickiness: Material adheres to the grinding surface or sieve surface of the mill. It is very difficult to powder a drug of having gummy or resinous material. 

iv. Material structure: Material with some special structure cause problem during size reduction e.g. Vegetable drug with cellular structure produce long fibrous particle on size reduction, similarly a mineral substance having lines of weakness, produce flake like particle on its size reduction.

v. Moisture  The presence of moisture in the material influence a number of its properties such as hardness, toughness or stickness.The material having 5% moisture in case of dry grinding and 50% in case of wet grinding is permissible.

vi. Temperature: Waxy material such as stearic acid or drug containing oils or fat, become softened during the size reduction, due to heat. This can be avoided by cooling the mill.

vii. Purity: In some mills during size reduction there is chances of addition of impurities. If high degree of purity is required avoid such mills or Mills should be cleaned thoroughly.

viii. Physiological effect: Some drugs are very potent. During there size reduction in mill, dust is produced which may have effect on operator.

ix. Ration of feed size to product size: To get a fine powder in a mill, it is required that a fairly small feed size should be used. Hence to carry out size reduction in various stages e.g. preliminary crushing followed by coarse powder and then fine grinding.

x. Bulk density: The output of the size reduction of the material in a machine depends upon the bulk density of the substance.

Related questions

Description : Define size reduction .What are different factors affecting to the rate of size reduction?

Last Answer : Size reduction is the process of reducing drugs into smaller pieces , coarse particles or fine powder. Factor affecting size reduction: 1.Hardness: Soft material easy break than hard. 2. ... size reduction of the material in a machine depends upon the bulk density of the substance.

Description : Explain any four factors affecting size reduction.

Last Answer : Factors affecting Size Reduction: i. Hardness: Soft material easytobreak than hard. ii. Toughness: Drug with fibrous nature or those having high moisture content are tough and hard to reduce in size ... the size reduction of the material in a machine depends upon the bulk density of the substance.

Description : Explain any four factors affecting size reduction

Last Answer : Factor affecting size reduction are:  1.Hardness: Soft material easy break than hard.  2.Toughness: Drug with fibrous nature or those having high moisture content are tough and hard to reduce in ... of the size reduction of the material in a machine depends upon the bulk density of the substance.

Description : What are the various factors which affect the size reduction of the drugs?

Last Answer : 1. Hardness: Soft material easy break than hard.  2. Toughness: Drug with fibrous nature or those having high moisture content are tough and hard to reduce in size.  3. Stickiness: Material ... of the size reduction of the material in a machine depends upon the bulk density of the substance. 

Description : Name various mechanisms of size reduction.

Last Answer : i. Cutting ii. Compression iii. Impact iv. Attrition v. Combined impact and attrition

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.

Description : Discuss factors affecting evaporation.

Last Answer : Factors affecting evaporation: 1) Temperature: The rate of evaporation is directly proportional to temp of liquid. 2) Temperature and time of evaporation: It has been observed that exposure ... : The rate of evaporation is directly proportional to the vapour pressure of the evaporating liquid.

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.

Description : Differentiate filtration and clarification. Enlist the different factors affecting the rate of filtration.

Last Answer : Sr.No. Filtration Clarification 1 It is the separation of an insoluble solid from a fluid or gas by means of a porous medium that retain the solid but allow the fluid to pass. ... be filtered. 6. Particle size: 7. Pore size of filter medium: 8. Nature of solid material:

Description : Define evaporation and explain any four factors affecting evaporation.

Last Answer : Definition:   Evaporation is the free escape of vapour from the surface of a liquid bellow its boiling point. Factors affecting evaporation: 1) Temperature: The rate of evaporation ... evaporated: The rate of evaporation is directly proportional to the vapour pressure of the evaporating liquid

Description : Explain any four factors affecting filtration. Draw a well labelled diagram of leaf filter.

Last Answer : Factors which affect the rate of filtration are:   1. Pressure: The rate of filtration of liquid is directly proportional to the pressure difference between the filter medium and filter cake. Thus, the ... cake increases which decreases the rate of filtration.  Diagram of leaf filter :

Description : Define evaporation. Explain any four factors affecting rate of evaporation.

Last Answer : Definition:  Evaporation is the free escape of vapour from the surface of a liquid bellow its boiling point. Factors affecting rate of evaporation:  1. Temperature: The rate of evaporation is ... The rate of evaporation is maximum at its boiling point when the liquid has maximum vapour pressure.

Description : Enlist four methods for size reduction. 

Last Answer : Methods for size reduction: i) Cutting ii) Compression iii) Impact iv) Attrition iv) Combined impact and attrition.

Description : List the importance of size reduction in pharmaceutical industries. 

Last Answer : Importance of size reduction ;-  i) To increase the rate of solution in case of chemical substance because reduction of particle size,increases the surface area for the action of solvent. ii) To allow ... form. vi) To help in the process of suppression of solid form liquids by filtration.

Description : What are the different mechanisms involved in the method of size reduction.

Last Answer : Cutting. Compression. Impact Attrition Combined impact and attrition 

Description : Write the importance of particle size reduction in pharmacy.

Last Answer : Can be listed as follows: i) Increase the rate of solution. ii) Increase the rate of penetration of solvent. iii) It helps in uniform mixing of drugs. iv) It increases the rate of absorption. v) Smaller the particles slower the rate of sedimentation. Thus stable the suspension.

Description : Mention different mechanisms for size reduction.

Last Answer : i. Cutting ii. Compression iii. Impact iv. Attrition v. Combined impact and attrition 

Description : Describe in detail various oral cavity tablet.

Last Answer : Oral cavity tablet:  i. Buccal Tablet. ii. Sublingual Tablet. iii. Lozenge tablet and tracheas. iv. Dental cones. 1] Buccal Tablet's - a. These tablets are to be placed in buccal pouch or ... Chloride or it may be amines acid. f. These cones generally get dissolved in 20 to 40 min time.

Description : Describe various stages of sugar coating. 

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

Description : Describe the factors which affect rate of the evaporation of liquid

Last Answer : Factors affecting evaporation:  1)Temperature: The rate of evaporation is directly proportional to temp of liquid.  2)Temperature and time of evaporation: It has been observed that exposure to ... : The rate of evaporation is directly proportional to the vapour pressure of the evaporating liquid.

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. 

Description : What are various ‘ Novel drug delivery systems’- explain implants. 

Last Answer : Various drug delivery systems are:  1. Implants 2. Liposome drug carriers 3. Nanoparticles 4. Prodrugs 5. Films and strips 6. Erythrocytes Implants: The hypodermic tablets are placed under the ... placed in the upper thigh at a depth of 5 mm. These implants are useful in hormone therapy.

Description : Name various types of closures.

Last Answer : i. Plug type. ii. Crown type. iii. Push-fit cap. iv. Screw closure

Description : Draw a well labelled diagram of ‘Soxhlet apparatus.’ Mention the various limitations of continuous hot percolation process. 

Last Answer : Limitation: 1. Physical character of the drug: If the drug would block the soxhlet apparatus then this process cannot be used for extraction. Eg opium. Gum, resin, ... for drugs having thermolabile active constituents such as enzymes, alkaloids, anthraquinone derivatives, esters, etc. 

Description : Explain the term aseptic techniques. What are the various points to be considered while designing an aseptic room?

Last Answer : Definition: The method which is used to prevent the access of microorganism during the preparation of parenteral product and their testing are called aseptic Technique . Design of aseptic room: 1. Site: ... connection. Vacuum. Disposable waste. 6. Furniture: Shack type. Fume -cupboard.

Description : Differentiate between filtration and clarification. Enlist various filter media used in Pharmacy.

Last Answer : Sr. no. Filtration Clarification 1 It is process of removal of solids or suspended matter in a liquid or gas by passing through a porous medium in which solids are retained. ... wool iv) Asbestos v) Fine muslin vi) Filter cloth vii) Membrane filters viii) Sintered glass filters.

Description : Name the various manufacturing defects in tablets. 

Last Answer : 1.Capping: In this there is partial or complete removal of top or bottom portion of tablet. Reasons: Excessive fine. Defective punch die. High speed of machine. Granules too dried ... ejection of tablet and give second impression. This can be controlled by managing the movement of punch.

Description : Name the various standards of sieves.

Last Answer : According to I.P. standards for sieves are as follows I .Approximate sieve number ii. Nominal mesh aperture size iii. Approximate percentage of sieving area iv. Tolerance average aperture size  According to I.P. sieves must confirm the above mentioned specifications for the given sieve number. 

Description : In which year various editions of pharmacopoeia of India came out?

Last Answer : 1. First Edition in 1955 2. Second Edition in 1966 3. Third Edition in 1985 4. Fourth Edition in 1996 5. Fifth Edition in 2007 6. Sixth Edition in 2010 7. Seventh Edition 2014

Description : Define tables. Enlist various excipients used in tablet manufacturing with one example each.

Last Answer : Definition:  Tablet is a solid unit dosage form congaing medicament/s usually circular in shape and may be flat or biconvex. OR Tablet is a solid unit dosage form prepared by compression. ... Glidants& lubricants: e.g. talc and magnesium stearate. vi. Colours, flavours and sweetening agents: 

Description : List the various equipment’s used for liquid mixing and explain how vortex formation can be avoided in liquid mixing. 

Last Answer : Equipment used for mixing of liquid:  1. Propeller mixture. 2. Turbine Mixture. 3. Paddle mixture. Vortex formation can be avoided in liquid mixing by making the following changes in the position of the ... the side of vessels. 4. Using push pull propeller. 5. Using baffles.

Description : Name various Novel drug Delivery systems.

Last Answer : 1. Implants 2. Liposome drug carriers 3. Nanoparticles 4. Prodrugs 5. Films and strips 6. Resealed Erythrocytes etc.

Description : What is aseptic technique? List the various sources of contamination and explain the sterility test.

Last Answer : 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 contamination: 1) ... the sample is declared to have pass the test and same test is repeated for two times.

Description : Explain various grades of powders

Last Answer : According to IP 2010 official grades of powders are as follows:  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 ... powder: A powder of which not less than 90%by weight of particles are less than 10 µm in size.

Description : Explain the factors which affect rate of filtration by Darcy’s law.

Last Answer : According to Darcy's Law, Where  v = volume of filtrate  K= permeability coefficient & is dependent on filter medium & filter cake.  A = Area of filter bed ... filtration. As the filtration process proceeds, thickness of cake increases which decreases the rate of filtration. 

Description : Explain the factors which affect the rate of evaporation of a liquid.

Last Answer : Factors affecting rate of evaporation: 1. Temperature: The rate of evaporation is directly proportional to the temperature of liquid. The evaporation can be accelerated by increasing the temp ... : The rate of evaporation is directly proportional to the vapour pressure of evaporating liquid.

Description : Name the factors which affects the rate of filtration. 

Last Answer : 2

Description : Based on Darcy’s law, discuss different factors which affect rate of filtration

Last Answer : This is also called as theory of filtration which gives idea about factors affecting rate of filtration through the filter medium. Any fluid while passing through porous medium offers resistance ... the filtration process proceeds, thickness of cake increases which decreases the rate of filtration.

Description : Name four factors affecting rate of reduction. 

Last Answer : 1) Nature of reactants 2) Temperature 3) Concentration 4) Catalyst

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.

Description : Draw a well labelled diagram of Vacuum still and describe its theory.

Last Answer : Theory :-  Liquid boils at lower temperature when pressure on the surface of the liquid is reduced. Therefore, when distillation is carried out under reduced pressure the rate of distillation increases. ... boiling point 100 ºc, at atmospheric pressure (760 mm of Hg ). Diagram: 

Description : Describe construction and working of double cone blender.

Last Answer : Diagram: Construction: Double cone blender is made up of stainless steel and is available in different capacity ranging from 5 kg to 200 kg or even more. The efficiency of ... to produce shearing action and design is useful for mixing powders of different densities in small quantities.

Description : Describe construction and working of equipment used for moist heat sterilization. 

Last Answer : Moist heat sterilizer or Autoclave:  Diagram:  Construction:  It consists of a string metallic chamber usually made of stainless steel. It has a cover fitted with a steam vent, pressure gauze ... whole of the steam is removed, the lid is opened and the sterilized material is taken out.

Description : Describe the construction and working of evaporating pan with neat diagram.

Last Answer : Construction:  i. It consists of a hemispherical pan made from copper or stainless steel and surrounded by a steam jacket. ii. Hemispherical shape provides large surface area for evaporation. iii. ... . iv. After evaporation remove the product from product outlet. Diagram:

Description : Describe the principle, construction, working and uses of cyclone separator.

Last Answer : Principle: Centrifugal force   Construction-  1) Cyclone separator is size separation device 2) It consists of a cylindrical vessel with a conical base. 3) The upper part of the vessel is fitted ... the suspension of a solid in gas 2. It can be used with liquid suspension of solid

Description : Describe in brief about ” churnas”

Last Answer : Churna: These are powdered mixture prepared by mixing dry mineral, animal or vegetable substance in a pestle and mortar in known as churna. The powdered mixture is then passed through cloth, linen or fine ... double the quantity of churna. They are generally taken with milk, hot water or cow urine.

Description : Describe in brief about dissolution test for tablets. 

Last Answer : Dissolution test: The test is done for measuring the amount of time required for a given percentage of drug substance in a tablet to go into solution under specified condition in vitro. The apparatus consists a ... ingredient in solution is not less than 70% of the stated amount.  Diagram.

Description : Describe dry heat method of sterilization in detail.

Last Answer : Principle: All the microorganism including spores are destroyed. Principle of killing is by dehydration and oxidation of essential metabolites. In hot air oven heating is done at 1600 C for 2 hours. ... off the oven. Allow to cool. Take out the material.  Diagram:

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.

Description : Describe simple maceration process.

Last Answer : Simple maceration is a maceration process for tinctures made from organised drugs. In this process, the drug is placed with the whole of the menstruum in a closed vessel for seven days. During ... made by simple maceration process are Tincture of Orange, Tincture of Lemon, Tincture of Squill, etc.