Extracts

Q: Define Extract?

Ans: Extracts are defined as concentrated preparation of vegetable or animal drugs obtained by removal of active constituents of the respective drug with menstruum, evaporation of all or nearly all of solvent, and adjustment of the residual masses or powders to the prescribed Standards.

Q: How many types of extracts are there?
Ans: There are three types of extracts:

• Semi liquid

• Solid extracts (Plastic masses)

• Powdered extracts (Dry powder)

Q: How the extracts are mostly prepared?
Ans: Mostly, extracts are prepared by extracting the drug by percolation.

Q: Why extracts are to be protected from heat?
Ans: The use of heat is avoided where possible because of potential injurious of active constituents

Q: Give some examples of extracts.
Ans: The examples of extracts are

• Extracts of Pure glycyrrhiza

• Extracts of Belladonna

Q: Define Fluid Extract?
Ans: USP define Fluid extract as being preparation of vegetable drugs containing alcohol as solvent or as a preservative or both, so that unless otherwise specified in an individual monograph, each milliliter contains the therapeutic constituents of 1g of the standard drug it represents.

Q: How unwanted colloidal material is separated and removed from fluid extract?
Ans: The fluid extract can be separated from the oil, concentrated by evaporation and re-extracted with strong alcohol to removed unwanted colloidal material.

Q: How degradation of fluid extract can occur?
Ans: Fluid extracts are subject to degradation by enzyme action.

Q: How degradation by enzyme is inhibited?
Ans: This can be inhibited by including alcohol to give a concentration of 25% or more but enzyme is not destroyed and concentration must be taken to avoid subsequent condition in which the enzyme activity can be restored.

Q: What are the Solvents and their advantages used in fluid extract?
Ans: Solvents used in fluid extract are

• Alcohol

• Water

• Solvent ether

• Acetic acid

Advantages of water and/or alcohol:

• It is cheap.

• It is non toxic.

• It can dissolve wide range of chemical substances.

• It flame and non-flamable.

Further Reading:
Remington: The Science and Practice of Pharmacy (Remington the Science and Practice of Pharmacy)

British Pharmacopoeia 2010

Infusion, Decoction and Tisane

Q: What is infusion? And also write some examples.

Ans: Infusions are liquid preparations, which are either prepared by infusion process or by diluting 1 part of concentrated infusion with 9 parts of water OR An infusion is the outcome of steeping plants with a desired flavor in water or oil.

Examples:

• Concentrated compound gention infusion.

• Concentrated senega infusion.

Q: What type of appratus is used in the preparation of infusion?
Ans: The simplest form of apparatus consists of BEAKER or a TEAPOT but special pots known as INFUSION POTS can also be used.

Q: How infusion is extracted?
Ans: The drug to be extracted is placed at the bottom of the pot, water is added and the content stirred occasionally or the drug may be enclosed in a piece of MUSLIN and suspended just below the level of the water.

The drug is allowed to remain in contact with water for the required time, which is usually 15 minutes. After the specified time, the liquid is strained and dispensed.

The marc is not pressed to avoid expression of colloidal cells into the final. Volume of the preparation is not adjusted by adding more of the vehicle otherwise dilution of active constituent will take place.

Q: How many types of infusion are used?
Ans: There are two types of infusion

• Freshly prepared infusion

• Concentrated infusion

Q: What do you know about the two types of infusions? And also give their examples.
Ans: 1. Freshly prepared infusion:

These must be used within 24 hours of its preparation.

Examples:

• Infusion of Senna.

• Infusion of quassia.

2. Concentrated infusion:

This infusion must be prepared by maceration or percolation process and alcohol is also used as a menstruum or a preservative.

Example:

• Concentrated infusion of Chirata.

• Concentrated infusion of gentian.

Q: What do you mean by decoction?
Ans: It is a method of extraction by boiling of dissolved chemicals, or plant material, which may include stems, roots, bark and rhizomes.

Decoctions differ from most teas, infusions, or tisanes in that they are usually boiled. The term is used colloquially in South India to refer to black coffee prepared by the traditional method.

Q: What is the etymology of decoction?
Ans: The term dates back to 1398, from present participle stem of Latin decoquere, (meaning to boil down), from de- + coquere "to cook".

Q: Write about process of decoction.
Ans: Decoction involves:

• First mashing and

• Then boiling in water to extract oils , volatile organic compounds and other chemical substances.

Q: How decoction is done in herbalism?
Ans: In herbalism, decoctions are usually made to extract fluids from hard plant materials such as roots and bark. To achieve this, the plant material is usually boiled for 8–10 minutes in water. It is then strained.

Q: What do you mean by tisane?
Ans: It is a type of infusion of flowers and leaves used in the form of herbal beverages such as herbal tea.

(This blog will help you in the preparation of Pharmacy Exams)

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Interesting books on Ancient medicines:

Aromatic Waters

Q: What are aromatic waters?

Ans: Aromatic waters are saturated solutions (unless otherwise specified) of volatile oils or other aromatic or volatile substances in distilled water. They are usually employed for flavoring. They are clear and free from solid impurities.

Q: Classify aromatic waters?

Ans:

• Simple aromatic waters

• Concentrated aromatic waters

Q: What do you know about concentrated aromatic waters?

Ans: These products are alcoholic, non-aqueous preparations containing 2% of volatile oils. They are forty times stronger than the ordinary aromatic waters. Many volatile oils contain aromatic part and non-aromatic part. The aromatic portion is much more soluble in a weak alcohol than the non-aromatic portion.

Q: What do you know about camphor water?

Ans: They are made by mixing racemic camphor with ethanol and by adding sufficient amount of water.

Q: What are the uses of camphor water?

Ans: Camphor water has been used as the vehicle in ophthalmic solutions owning to its ability to contribute refreshing, stimulating effect to the preparation.

Q: How aromatic waters smell?

Ans: They possess an odor similar to the plant or volatile substance from which they are made. They are free from foreign odor.

Q: How aromatic waters should be stored?

Ans: Aromatic water deteriorates with time and it should be made in small quantities and protected.

(These Viva Type Questions will help you to prepare for Pharmacy Exams)

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Interesting books:

Tinctures

Q: What are tinctures?

Ans: These are alcoholic or hydroalcoholic solutions made from materials of plant origin or from chemical substances. Most of the tinctures are prepared by percolation or by maceration.

Q: What is the method generally used for the preparation of tinctures?
Ans: Herbs are placed in a container and a spirit containing 40% pure ethanol is added. The jar is placed for 2-3 weeks and shaken occasionally so that the concentration can be increased of the solution.

Q: What are the examples of tincture?
Ans: Iodine tincture, alcoholic tincture, digitalis tincture, belladonna tincture

Q: What do you know about iodine tincture?
Ans: It is a hydroalcoholic solution having

• Elemental iodine i.e. 2%,

• Potassium iodide i.e. 2.4%, so that the dissolution is facilitated and

• Alcohol i.e. 47%.

Q: What is the use of iodine tincture?
Ans: It is used as an antiseptic/germicide for scratches and cuts on the surface of the skin. It has been used as a skin disinfectant before surgery but is now largely replaced by organic forms of iodine.

Q: What do you know about belladonna tincture?
Ans: It is a green hydroalcoholic liquid having the alkaloids scopolamine and atropine and other substances that are extracted from the leaves of Atropa belladonna.

Q: What is the use of belladonna tincture?
Ans: Earlier it was widely used in treatment of ulcer or the palliative treatment of diarrhea, either alone or in combination with antacids and insoluble clays.

Q: What do you mean by palliative treatment?
Ans: It means the relief of mental and physical pain or symptoms without actually treating the causes, especially in patients suffering from a fatal (dying) illness.

(These Viva type Questions can help you in the preparation of pharmacy exams)
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Further Reading:

Surface tension

Q: What do you mean by surface tension?

Ans: It represents the intermolecular attraction due to cohesive quality at the surface of the liquid, in contact with another fluid or solid, which tends to move the molecules of the liquid inside from the surface.
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Further Reading:

Suspensions

In chemistry, a suspension is a heterogeneous fluid containing solid particles that are sufficiently large for sedimentation. Usually they must be larger than 1 micrometer. The internal phase (solid) is dispersed throughout the external phase (fluid) through mechanical agitation, with the use of certain excipients or suspending agents. Unlike colloids, suspensions will eventually settle. An example of a suspension would be sand in water. The suspended particles are visible under a microscope and will settle over time if left undisturbed. This distinguishes a suspension from a colloid, in which the suspended particles are smaller and do not settle.Colloids and suspensions are different from solutions, in which the dissolved substance (solute) does not exist as a solid, and solvent and solute are homogeneously mixed.

A suspension of liquid droplets or fine solid particles in a gas is called an aerosol or particulate. In the atmosphere these consist of fine dust and soot particles, sea salt, biogenic and volcanogenic sulfates, nitrates, and cloud droplets.

Suspensions are classified on the basis of the dispersed phase and the dispersion medium, where the former is essentially solid while the latter may either be a solid, a liquid, or a gas.

In modern chemical process industries, high shear mixing technology has been used to create many novel suspensions.

Suspensions are unstable from the thermodynamic poin of view; however, they can be kinetically stable over a large period of time, which determines their shelf life. This time span needs to be measured to ensure the best product quality to the final consumer. “Dispersion stability refers to the ability of a dispersion to resist change in its properties over time.” D.J. McClements.

Destabilisation phenomenon of dispersion:
These destabilisations can be classified into two major processes:

1-Migration phenomena : whereby the difference in density between the continuous and dispersed phase, leads to gravitational phase separation. In the case of suspensions sedimentation occurs as the dispersed phase is denser than the continuous phase.

2-Particle size increase phenomena: whereby the suspended particles join together and increase in size. Below are the two types of this phenomena.

• reversibly (flocculation)
• irreversibly (aggregation)

 Technique monitoring physical stability:
Multiple light scattering coupled with vertical scanning is the most widely used technique to monitor the dispersion state of a product, hence identifying and quantifying destabilisation phenomena. It works on concentrated dispersions without dilution. When light is sent through the sample, it is backscattered by the particles. The backscattering intensity is directly proportional to the size and volume fraction of the dispersed phase. Therefore, local changes in concentration (sedimentation) and global changes in size (flocculation, aggregation) are detected and monitored.

Accelerating methods for shelf life protection:
The kinetic process of destabilisation can be rather long (up to several months or even years for some products) and it is often required for the formulator to use further accelerating methods in order to reach reasonable development time for new product design. Thermal methods are the most commonly used and consists in increasing temperature to accelerate destabilisation (below critical temperatures of phase inversion or chemical degradation). Temperature affects not only the viscosity, but also interfacial tension in the case of non-ionic surfactants or more generally interactions forces inside the system. Storing a dispersion at high temperatures enables to simulate real life conditions for a product (e.g. tube of sunscreen cream in a car in the summer), but also to accelerate destabilisation processes up to 200 times.
Mechanical acceleration including vibration, centrifugation and agitation are sometimes used. They subject the product to different forces that pushes the particles / droplets against one another, hence helping in the film drainage. However, some emulsions would never coalesce in normal gravity, while they do under artificial gravity. Moreover, segregation of different populations of particles have been highlighted when using centrifugation and vibration.

Objective Type Questions for Suspensions in Pharmaceutics

1.    A pharmaceutical suspension is defined as a ………………….. ,in which insoluble drug particles are dispersed in liquid medium .                     
 ----------------------
2.    In suspensions ,the partical size ranges b/w…………………..
-----------------------
3.    Following is not the important reason of the suspensions :

a) drug stability      
b) taste improving     
c) taste masking    
d) compatibility                
-----------------------
4.    Suspensions are preferred over tablets & capsules due to     …………………in dosage forms -----------------------
5.    The particle size is important while determining the rate of ……………………..          
-----------------------
6.    During sedimentation , not to form a ………………… is an important feature of the good suspension -----------------------
7.    A good suspension should be resistant to………………….
-----------------------
8.    The ……………….. of a good suspension should not be too much to pour.                        
-----------------------
9.    Such suspensions which are prepared just before dispensing to the patients are called …………………..                                                  
-----------------------
10.    Extemporaneous suspensions are prepared from:  

a)    tablets & capsules
b)    just before dispensing to the patient
c)    contents are crushed in mortar & pestle and a proper vehicle is added
-----------------------
11.For preparation of the extemporaneous  suspensions  , a good quality suspending agent is added which is :

a) cheep  in cost
b) less liable to microbial attack
c) less liable to be coagualated                                                          
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12.   Carboxymethyl cellulose  is an important …………………………. Used in preparation of the extemporaneous suspensions                                                 
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13.   USP designs the extemporaneous suspensions as ………………………..          
------------------------
14.    Paediatric antibiotics suspensions are best examples of the ………………………
------------------------
15. Reconstituted suspensions are also called as   ……………………………..                               
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16.  Reconstituted suspensions are designated by usp as…………………………                     
------------------------
17.    While preparing reconstituted suspensions ;active agents ,sweeteners, colorants ,flavouring agents ,stabilizers, suspending agents are mixed to prepare a ………………powder.                             
------------------------
18.    Previously boiled  & cooled  water is added in …………………………… while preparing ------------------------
19.  The commercial reconstituted suspensions available  is ……………………..                   
------------------------
20.     The condition in which the particles don’t aggregate and in which they remain uniformly distributed throughout the distributed throughout the dispersion and donot settle is celled …………………….                                           
------------------------
21.   Rate of the sedimentation is determined while preparing  by ………………. Law .                           
------------------------
22.  while preparing suspensions , all factors are adjusted so that the rate of the sedimentation is ……………..                       

a) maximum             
b) minimum     
c) medium                                   
------------------------
23.    While preparing the suspensions , the relation b/w density and sedimentation  is …………………                          
------------------------
24.     The particle size of the dispersed phase of the suspensions ranges b/w …………………….            

a) 1 to 50 µm      
b) 2 to 10 mm          
c) 1 to 10 µm
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Answers to Objective Type Questions for Suspensions in Pharmaceutics

1. coarse dispersion
2. 10-15micrometer
3. b
4. flexibility
5. sedimentation
6. hard cake
7. microbial attack
8. viscosity
9. Extemporaneous suspensions
10. a
11. b
12. suspending agent
13. ORAL  SUSPENSIONS
14. extemporaneous suspensions
15. powders for oral suspensions
16. for oral suspensions
17. homogenous
18. reconstituted suspension
19. Barium sulphate
20. physical stability
21. stokes'
22. b
23. inverse
24. a

(These Objective type questions are helpful for the preparation of Pharmacy Exams)

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Further Reading:

Remington: The Science and Practice of Pharmacy (Remington the Science and Practice of Pharmacy)

Tutorial pharmacy

Textbook of Pharmaceutics

Martin's Physical Pharmacy and Pharmaceutical Sciences

Colloids and Emulsions

An emulsion is a mixture of two or more immiscible (unblendable) liquids. Emulsions are part of a more general class of two-phase systems of matter called colloids. Although the terms colloid and emulsion are sometimes used interchangeably, emulsion tends to imply that both the dispersed and the continuous phase are liquid. In an emulsion, one liquid (the dispersed phase) is dispersed in the other (the continuous phase).

Examples of emulsions include vinaigrettes, the photo-sensitive side of photographic film, milk and cutting fluid for metal working.

Structure and properties of emulsions:
It is still common belief that emulsions basically do not display any structure, i.e., the droplets (or in case of dispersions, particles) dispersed in the liquid matrix (the “dispersion medium”) are assumed to be statistically distributed. Therefore, for emulsions (like for dispersions) usually percolation theory is assumed to appropriately describe their properties.

However, percolation theory can only be applied if the system it should describe is in or close to thermodynamic equilibrium. There are very few studies about the structure of emulsions (dispersions), although they are plentiful in type and in use all over the world in innumerable applications.

In the following, only such emulsions will be discussed with a dispersed phase diameter of less than 1 µm. To understand the formation and properties of such emulsions (including dispersions), it must be considered, that the dispersed phase exhibits a "surface," which is covered ("wet") by a different "surface" which hence are forming an interface (chemistry). Both surfaces have to be created (which requires a huge amount of energy), and the interfacial tension (difference of surface tension) is not compensating the energy input, if at all.

Appearance and properties

Emulsions are made up of a dispersed and a continuous phase; the boundary between these phases is called the interface. Emulsions tend to have a cloudy appearance, because the many phase interfaces scatter light that passes through the emulsion. Emulsions are unstable and thus do not form spontaneously. The basic color of emulsions is white. If the emulsion is dilute, the Tyndall effect will scatter the light and distort the color to blue; if it is concentrated, the color will be distorted towards yellow. This phenomenon is easily observable on comparing skimmed milk (with no or little fat) to cream (high concentration of milk fat). Microemulsions and nanoemulsions tend to appear clear due to the small size of the disperse phase.

Energy input through shaking, stirring, homogenizing, or spray processes are needed to initially form an emulsion. Over time, emulsions tend to revert to the stable state of the phases comprising the emulsion; an example of this is seen in the separation of the oil and vinegar components of Vinaigrette, an unstable emulsion that will quickly separate unless shaken continuously.

Whether an emulsion turns into a water-in-oil emulsion or an oil-in-water emulsion depends on the volume fraction of both phases and on the type of emulsifier. Generally, the Bancroft rule applies: emulsifiers and emulsifying particles tend to promote dispersion of the phase in which they do not dissolve very well; for example, proteins dissolve better in water than in oil and so tend to form oil-in-water emulsions (that is they promote the dispersion of oil droplets throughout a continuous phase of water).

Instability

There are three types of instability: flocculation, creaming, and coalescence. Flocculation describes the process by which the dispersed phase comes out of suspension in flakes.Coalescence is another form of instability, which describes when small droplets combine to form progressively larger ones. Emulsions can also undergo creaming, the migration of one of the substances to the top (or the bottom, depending on the relative densities of the two phases) of the emulsion under the influence of buoyancy or centripetal force when a centrifuge is used.

Surface active substances (surfactants) can increase the kinetic stability of emulsions greatly so that, once formed, the emulsion does not change significantly over years of storage. A Non-Ionic surfactant solution can become self-contained under the force of its own surface tension, remaining in the shape of its previous container for some time after the container is removed. Superfluids flow with zero friction and can escape their containers; an ionic solution tends to retain its current shape.

“Emulsion stability refers to the ability of an emulsion to resist change in its properties over time.” D.J. McClements.

Technique monitoring physical stability

Multiple light scattering coupled with vertical scanning is the most widely used technique to monitor the dispersion state of a product, hence identifying and quantifying destabilisation phenomena. It works on concentrated emulsions without dilution. When light is sent through the sample, it is backscattered by the droplets. The backscattering intensity is directly proportional to the size and volume fraction of the dispersed phase. Therefore, local changes in concentration (Creaming) and global changes in size (flocculation, coalescence) are detected and monitored.

Accelerating methods for shelf life prediction

The kinetic process of destabilisation can be rather long (up to several months or even years for some products) and it is often required for the formulator to use further accelerating methods in order to reach reasonable development time for new product design. Thermal methods are the most commonly used and consists in increasing temperature to accelerate destabilisation (below critical temperatures of phase inversion or chemical degradation). Temperature affects not only the viscosity, but also interfacial tension in the case of non-ionic surfactants or more generally interactions forces inside the system. Storing a dispersion at high temperatures enables to simulate real life conditions for a product (e.g. tube of sunscreen cream in a car in the summer), but also to accelerate destabilisation processes up to 200 times.

Mechanical acceleration including vibration, centrifugation and agitation are sometimes used. They subject the product to different forces that pushes the droplets against one another, hence helping in the film drainage. However, some emulsions would never coalesce in normal gravity, while they do under artificial gravity. Moreover segregation of different populations of particles have been highlighted when using centrifugation and vibration.

Emulsifier

An emulsifier (also known as an emulgent) is a substance which stabilizes an emulsion by increasing its kinetic stability. One class of emulsifiers is known as surface active substances, or surfactants. Examples of food emulsifiers are egg yolk (where the main emulsifying agent is lecithin), honey, and mustard, where a variety of chemicals in the mucilage surrounding the seed hull act as emulsifiers; proteins and low-molecular weight emulsifiers are common as well. Soy lecithin is another emulsifier and thickener. In some cases, particles can stabilize emulsions as well through a mechanism called Pickering stabilization. Both mayonnaise and Hollandaise sauce are oil-in-water emulsions that are stabilized with egg yolk lecithin or other types of food additives such as Sodium stearoyl lactylate.

Detergents are another class of surfactant, and will physically interact with both oil and water, thus stabilizing the interface between oil or water droplets in suspension. This principle is exploited in soap to remove grease for the purpose of cleaning. A wide variety of emulsifiers are used in pharmacy to prepare emulsions such as creams and lotions. Common examples include emulsifying wax, cetearyl alcohol, polysorbate 20, and ceteareth 20. Sometimes the inner phase itself can act as an emulsifier, and the result is nanoemulsion - the inner state disperses into nano-size droplets within the outer phase. A well-known example of this phenomenon, the ouzo effect, happens when water is poured in a strong alcoholic anise-based beverage, such as ouzo, pastis, arak or raki. The anisolic compounds, which are soluble in ethanol, now form nano-sized droplets and emulgate within the water. The colour of such diluted drink is opaque and milky.

In pharmaceutics, hairstyling, personal hygiene and cosmetics, emulsions are frequently used. These are usually oil and water emulsions, but which is dispersed and which is continuous depends on the pharmaceutical formulation. These emulsions may be called creams, ointments,liniments (balms), pastes, films or liquids, depending mostly on their oil and water proportions and their route of administration. The first 5 are topical dosage forms, and may be used on the surface of the skin, transdermally, ophthalmically, rectally or vaginally. A very liquidy emulsion may also be used orally, or it may be injected using various routes (typically intravenously or intramuscularly). Popular medicated emulsions include calamine lotion, cod liver oil, Polysporin, cortisol cream, Canesten and Fleet.

Microemulsions are used to deliver vaccines and kill microbes.Typically, the emulsions used in these techniques are nanoemulsions of soybean oil, with particles that are 400-600 nm in diameter. The process is not chemical, as with other types of antimicrobial treatments, but mechanical. The smaller the droplet, the greater the surface tension and thus the greater the force to merge with other lipids. The oil is emulsified using a high shear mixer with detergents to stabilize the emulsion, so when they encounter the lipids in the membrane or envelope of bacteria or viruses, they force the lipids to merge with themselves. On a mass scale, this effectively disintegrates the membrane and kills the pathogen. This soybean oil emulsion does not harm normal human cells nor the cells of most other higher organisms. The exceptions are sperm cells and blood cells, which are vulnerable to nanoemulsions due to their membrane structures. For this reason, these nanoemulsions are not currently used intravenously. The most effective application of this type of nanoemulsion is for the disinfection of surfaces. Some types of nanoemulsions have been shown to effectively destroy HIV-1 and various tuberculosis pathogens, for example, on non-porous surfaces.

Uses:

Emulsions are mainly used in many major chemical industries. In the pharmaceutical industry they are used to make medicines with a more appealing flavor and to improve value by controlling the amount of active ingredients. The most widely-used emulsions are non-ionic because they have low toxicity, but cationic emulsions are also used in some products because of their antimicrobial properties. Emulsions are also used in making many hair and skin products, such as various types of oils and waxes.

Objective Type Questions of Colloids and Emulsions in Pharmacy

1.    An emulsion is a ......................of two immiscible liquid phases, one of which is dispersed as fine globules throughout the other.                                                
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2.    Basically emulsion may is thermodynamically................................ System of at least two immiscible liquid phases.        

a) stable ,           
b) turbid         
c) clear         
d) unstable               
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3.    The stability of the emulsion is measured in terms of the quantity of the ............................... agent used.           

a) binding agent         
b) suspending agent          
c) emulsifying agent  
d)  both a& b                             
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4.    The liquid phase in the form of  globules is called as.................................
------------------
5.    The liquid bearing the globules of the other phase is called as :

a) fluorescent phase       
b) saturated layer          
c) fatty layer         
d) continuous phase                
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6.    Dispersed phase can consist of the ..............................    

a) stable liq.       
b) mobile liq       
c) semisolids 
d) plasma          
e) both b&c                      
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7.    The most important example of the emulsion that is therapeutically active:

a) lotions      
b) creams
c) ointments  
d) both a & c                                
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8.    In emulsions ,the particle size ranges:         

a) 0.5 - 1 mm           
b) 0.1 - 4         
c) 0.1 - 10mm          
d) 0.1 -10 micrometers                            
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9.    In the preparation of the emulsions ,the most important and most frequently used phase is :

a) alkenes      
b) ether         
c) chloroform      
d) water 
e) alcohols               
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10.    In o/w emulsion, can the globules of the dispersed phase show fluorescence?       

a) yes     
b) no                
-------------------
11.    In o/w emulsions the continuous phase is ..............................                      
-------------------
12.    Milk is an important example of the................................ emulsion               
-------------------
13.    Egg yolk is an important example of...................       emulsion                     
-------------------
14.    In water in oil emulsions ,the globules contain .....................                     
--------------------
15.    Following is the important w/o emulsion used most frequently :

a) rubber latex     
b) vanishing cream   
c) oily calamine lotion
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Answers to Objective Type Questions of Colloids and Emulsions in Pharmacy 

1. system
2. d
3. c
4. dispersed phase
5. d
6. e
7. c
8. d
9. d
10. a
11. water
12. o/w
13. o/w
14. water
15. c

(These Objective Type Questions are helpful for the preparation of Pharmacy Exams)

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Further Reading:
Tutorial pharmacy

Martin's Physical Pharmacy and Pharmaceutical Sciences

Remington: The Science and Practice of Pharmacy (Remington the Science and Practice of Pharmacy)

Textbook of Pharmaceutics

Colloids and Emulsions

Objective Type Questions from Colloids and Emulsions in Pharmacy

16.    An emulsion in which water globules are dispersed within the oil globules so that the system may be designated as ..................................                                
--------------------
17.    medically used emulsions for oral administration are usually ...............type:

a)o/w        
b) w/o 
c) w/o/w        
d) o/w/o                             
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18.    The surface active agents used in multiple emulsions are:

a) non-ionic  
b) synthetic      
c) ionic    
d) natural      
e ) a&b   
f) c&d                             
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19.    Gelatin and Tragacanth are :

a) emulsifying agents    
b) surface active agents  
c) synthetic non-ionic     
d) b&c       
e) a&c                             
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20.    W/O  emulsions are used almost exclusively for....................... applications :

a) internal      
b) external       
c) causal                      
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21.    Calcium palmitate , spans , cholesterol and wool fat  are emulsifiers used in the preparation of :       

a) w/o  
b) o/w 
c) w/o/w      
d) o/w/o                            
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22.    Dye solubility test is mostly used for ..................of the emulsion type.  
----------------------
23.    Mostly used dye in the dye solubility test is .......................................                 
----------------------
24.    At commercial level,………………………..is used for dilution method of determination of the emulsion thpe.        

a) ether   
b) alcohol       
c) water     
d) choloroform                   
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25.    During conduction method ,the electrical circut completes when continuous phase is ......................                     
----------------------
26.    Co lour of the o/w  emulsion is usually...................................             
----------------------
27.    Initially o/w emusion feels ................................on the skin.                  
----------------------
28.    When we add oil soluble dye in the o/w emulsion, the colored phase will be ……………….                       
----------------------
29.    The British chemist Thomas Graham applied the term “colloid” to : 

a)polypeptides  
b) polysaccharides
c) flavones   
d) a&b                               
-----------------------
30.    Colloidal dispersions are distinguished form the solutions and coarse dispersions on the basis of the :

a) viscosity   
b) density    
c) particle size                            
-----------------------
31.    Most of the pharmaceutical systems are prepared in the form of the :

a) hydrophilic colloidal system       
b) lipophilic colloidal system                         
-----------------------
32.    Radioactive colloids are being used as diagnostic & ……………….. Purposes in nuclear medicines.                         
-----------------------
33.    micelles, microemulsions,liposomes, parenteral emulsions ,micro spheres ,nanoparticles are known as ……………………
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Answers to Objective Type Questions from Colloids and Emulsions in Pharmacy 

16. w/o/w
17. a
18. e
19. d
20. b
21. a
22. determination
23. methylene-blue
24. c
25. water
26. milky white
27. non-greasy
28. dispersed phase
29. d
30. c
31. a
32. therapeutic
33. Colloidal drug delivery systems

(These Objective Type Question are helpful for the preparation of Pharmacy Exams)

------------------------

Further Reading:

Tutorial pharmacy

Remington: The Science and Practice of Pharmacy (Remington the Science and Practice of Pharmacy)

Martin's Physical Pharmacy and Pharmaceutical Sciences

Textbook of Pharmaceutics

IV admixtures

Multiple Choice Questions (MCQs) from IV admixtures in Pharmaceutics

1:  --------------------  is the preparation of pharmaceutical product that requires the measured additive of medication to a 50ml or larger bag or bottle of IV fluid.

a)    Admixture
b)    Suspension
c)    IV admixture
d)    Emulsion
-----------------
2:  The drug added to an IV solution is called -------------------- .

a)    Excipients
b)    Sodium chloride
c)    Dextrose
d)    Additive
----------------
3:  All different types of parenteral drug delivery systems are true EXCEPT--------------

a)    Decrease the safety of parenteral medications.
b)    Patient controlled analgesia
c)    Home IV therapy
d)    Home TPN
--------------
4:  Any solution administered to the patient`s veins must be -----------------

a)    Non-sterile
b)    Sterile & Pyrogen free
c)    Endotoxins
d)    Irritating
--------------
5:  Intravenous admixtures are ----------------- to which one or more additional drugs or solutions have been added.

a)    Mixtures
b)    Suspension
c)    Small volume parenteral
d)    Large volume parenteral (LVP)
---------------
6:  The intravenous admixture product should be --------------------

a)    Free of contamination (Particles, bacteria,extraneous material)
b)    The solution should be clear (All medications should be completely dissolved)
c)    Both a & b
d)    None of above.
----------------
7:  The ------------------  route is most dangerous route of administration because it by passes all of body`s natural barriers.

a)    Intra-muscular
b)    Intra-occular
c)    Both a & b
d)    Intra-venous
----------------
8:  An improperly prepared solution when administered can have very serious consequences like ----------------------

a)    Infections
b)    Emboli
c)    Occlusions
d)    All of above

-----------------

Answers to Multiple Choice Questions (MCQs) from IV admixtures in Pharmaceutics

1. c) IV admixture
2. d) Additive
3. a) Decrease the safety of parenteral medications.
4. b) Sterile & pyrogen free
5. d) Large volume parenteral (LVP)
6. c) Both a & b
7. d) Intra-venous
8. d) All of above

(These MCQs are helpful for the preparation of Pharmacy Exams)

-----------------------

Further Reading:

TUTORIAL PHARMACY

Textbook of Pharmaceutics

Remington: The Science and Practice of Pharmacy (Remington the Science and Practice of Pharmacy)

British Pharmacopoeia 2010

Ansel's Pharmaceutical Dosage Forms and Drug Delivery Systems

Capsules

In the manufacture of pharmaceuticals, encapsulation refers to a range of techniques used to enclose medicines in a relatively stable shell known as a capsule, allowing them to, for example, be taken orally or be used as suppositories. The two main types of capsules are:

• Hard-shelled capsules, which are normally used for dry, powdered ingredients or miniature pellets (also called spheroids that are made by the process of Extrusion and Spheronization - Spheronization is a trade mark of Caleva Process Solutions) or tablets;
• Soft-shelled capsules, primarily used for oils and for active ingredients that are dissolved or suspended in oil.

Both of these classes of capsules are made from aqueous solutions of gelling agents like:

• Animal protein mainly gelatin;
• Plant polysaccharides or their derivatives like carrageenans and modified forms of starch and cellulose.

Other ingredients can be added to the gelling agent solution like plasticizers such as glycerin and/or sorbitol to decrease the capsule's hardness, coloring agents, preservatives, disintegrants, lubricants and surface treatment.

Since their inception, capsules have been viewed by consumers as the most efficient method of taking medication. For this reason, producers of drugs such as OTC analgesics wanting to emphasize the strength of their product developed the "caplet" or "capsule-shaped tablet" in order to tie this positive association to more efficiently-produced tablet pills. After the 1982 Tylenol tampering murders, capsules experienced a minor fall in popularity as tablets were seen as more resistant to tampering.

 Single piece gel encapsulation:
In 1834, Mothes and Dublanc were granted a patent for a method to produce a single-piece gelatin capsule that was sealed with a drop of gelatin solution. They used individual iron moulds for their process, filling the capsules individually with a medicine dropper. Later on, methods were developed that used sets of plates with pockets to form the capsules. Although some companies still use this method, the equipment is not produced commercially any more. All modern soft-gel encapsulation uses variations of a process developed by R.P. Scherer in 1933. His innovation was to use a rotary die to produce the capsules, with the filling taking place by blow molding. This method reduced wastage, and was the first process to yield capsules with highly repeatable dosage.
The current owner of the RPScherer technology is Catalent Pharma Solutions, the world's largest manufacturer of prescription pharmaceutical softgels.
Softgels can be an effective delivery system for oral drugs, especially poorly soluble drugs. This is because the fill can contain liquid ingredients that help increase solubility or permeability of the drug across the membranes in the body. Liquid ingredients are difficult to include in any other solid dosage form such as a tablet. Softgels are also highly suited to potent drugs (for example, where the dose is <100 ug), where the highly reproducible filling process helps ensure each softgel has the same drug content, and because the operators are not exposed to any drug dust during the manufacturing process.
In 1949, the Lederle Laboratories division of the American Cyanamid Company developed the "Accogel" process, allowing powders to be accurately filled into soft gelatin capsules.

Two piece gel encapsulation:
James Murdock of London patented the two-piece telescoping gelatin capsule in 1847. The capsules are made in two parts by dipping metal rods in the gelling agent solution. The capsules are supplied as closed units to the pharmaceutical manufacturer. Before use, the two halves are separated, the capsule is filled with powder or mor normallt spheroids made by the process of spheronization (either by placing a compressed slug of powder into one half of the capsule, or by filling one half of the capsule with loose powder) and the other half of the capsule is pressed on. With the compressed slug method, weight varies less between capsules. However, the machinery required to manufacture them is more complex.
The powder or spheroids inside the capsule contains the active ingredient(s) and any excipients, such as binders, disintegrants, fillers, glidant, and preservatives.

Osmotic-controlled Release Oral delivery System (OROS):
OROS is a controlled release oral drug delivery system in the form of a consumable capsule. The capsule has a rigid water-permeable jacket with one or more small holes. As the capsule passes through the body, the osmotic pressure of water entering the capsule pushes the active drug through the opening in the capsule.
OROS is a trademarked name owned by Alza Corporation.

Multiple Choice Questions (MCQs) from Capsules in Pharmaceutics

1-  Capsule are dosage form contain ______ of drug.

a) single dosage  
b) unit dosage    
c) double dosage   
d) both b & c
---------------
2-  Basic empty capsule shell are made from a mixture of ______.

a) sugar   
b) water  
c) Galeton 
d) all of above
---------------
3-  Galeton is ______ in air when dry.

a) Unstable  
b) stable   
c) both a & b  
d) none of above
---------------
4-  Soft Galeton capsule have ______ moisture content then hard Galeton capsule.

a) low  
b) equal  
c) high   
d)  none of above
---------------
5-  The normal shell contain _____ of moisture.

a) 9-12%  
b) 15-18%  
c) 12-15%      
d) none of above
---------------
6-  Capsule are _____ to swallowed.

a) very difficult     
b) difficult    
c) both a & b   
d) easy
----------------
7-  On large scale soft Galeton capsule are prepared by_______.

a) plate process    
b) rotator die process  
c) both a & b    
d) none of above
-----------------
8-  The hard Galeton capsule are produced by mechanical dipping of _______ of desire able shape and diameter.

a) pins    
b) pegs     
c) both a & b      
d) none of above
------------------
9-  Hard Galeton capsule contain ______ of moisture.

a) 9-12%  
b) 15-18%  
c) 12-15%      
d) none of above
------------------
10-  Capsule are should be stored at ____ and ____ humidity level.

a) dry , low   
b) dry , high   
c) cool , high   
d) cool , low
------------------
11-  Examples  of drug dispensed in soft Galeton capsule are ¬¬¬¬¬_______.

a) volatile drug  
b) liquid , suspension , powders e.t.c    
c) vitamin E , digoxin e.t.c   
d) all of above
------------------

Answers to Multiple Choice Questions (MCQs) from Capsules in Pharmaceutics

•    1- b
•    2- d
•    3- b
•    4- c
•    5- c
•    6- d
•    7- c
•    8- c
•    9- a
•    10- d
•    11- c

(These MCQs are helpful for the preparation of Pharmacy Exams)

--------------------

Further Reading:

Ansel's Pharmaceutical Dosage Forms and Drug Delivery Systems

Remington: The Science and Practice of Pharmacy (Remington the Science and Practice of Pharmacy)

British Pharmacopoeia 2010

Cooper and Gunn's Dispensing for Pharmaceutical Students

Rheology

Multiple Choice Questions (MCQs) from Rheology in Pharmaceutics

1: The principle method for measuring viscosity is;

a)     Capillary viscometer
b)     Concentric cylinder viscometer
c)     Falling or rolling sphere viscometer
d)     All of the above
e)     Both a & b
--------------------
2: Materials whose consistency depends on the duration of shear as wheel as on the rate of shear, exhibit;

a)    Rheopexy
b)    Thixotropy
c)    Viscoelasticity
d)    Plasticity
--------------------
3: Fluids that do not abbey Newton’s law are described as;

a)    Time dependent non-Newtonian fluids
b)    Time independent non-Newtonian fluids
c)    Newtonian fluids
d)    Both a & b
e)    None of them
---------------------
4: Elastic deformation is described by;

a)    Hook’s law
b)    Newton’s law
c)    Empirical power law
d)    Stock’s law
---------------------
5: The ratio of relaxation time of a material to the time scale of a deformation is called;
a)    Reynolds number
b)    Weissenberg number
c)    Deborah number
d)    Mass number
---------------------
6: If neither the deformation strain, nor its derivative with time (rate) follows the applied stress then the material is:

a)    Elastic
b)    Solid
c)    Viscoelastic
d)    Fluid
---------------------------

Answers to Multiple Choice Questions (MCQs) from Rheology in Pharmaceutics

1: The principle method for measuring viscosity is;
Answer: -   d) All of the above

2: Materials whose consistency depends on the duration of shear as wheel as on the rate of shear, exhibit;
Answer:-   b) Thixotropy

3: Fluids that do not abbey Newton’s law are described as;
Answer:-   d) Both a & b

4: Elastic deformation is described by;
Answer:-   a) Hook’s law

5: The ratio of relaxation time of a material to the time scale of a deformation is called;
Answer:-    c) Deborah number

6: If neither the deformation strain, nor its derivative with time (rate) follows the applied stress then the material is:
Answer:-   c) Viscoelastic

(These MCQs are helpful for the preparation of Pharmacy Exams)

------------------------

Further Reading:
TUTORIAL PHARMACY

Textbook of Pharmaceutics

Remington: The Science and Practice of Pharmacy (Remington the Science and Practice of Pharmacy)

Ansel's Pharmaceutical Dosage Forms and Drug Delivery Systems