Furthermore, another significant difference between flocculation and deflocculation is that flocculation decreases the viscosity of a suspension, whereas deflocculation increases the viscosity of a suspension. As a result, the rate of sedimentation in a flocculated suspension is higher than the rate of sedimentation in a deflocculated suspension.
What is A deflocculated suspension?
A deflocculated suspension is a suspension where no flocculation has taken place. Particles exist as separate entities. Rate of sedimentation is low. Sediment formed slowly.
What is the difference between a suspension and a flocculated system?
A suspension is also called a dispersed system since there are particles all over the liquid. Flocculation is the formation of floccules in a suspension. That can happen spontaneously or due to the presence of flocculating agents. There are suspensions that can be either flocculated or deflocculated.
Why is the rate of sedimentation slow in deflocculated suspensions?
In a deflocculated suspension, collide particles act as individual particles, and there are no flocs or aggregates. Here, the rate of sedimentation is slow because smaller particles rather than large clusters of particles are involved in settling.
What is the difference between flocculation and sedimentation?
Flocculation is the process in which colloids in a suspension can be obtained in an aggregated form. Therefore, a flocculated suspension is composed of large aggregates and this type of suspension will lead to a rapid rate of sedimentation. Sedimentation is the settling down of aggregates or particles of suspension to the bottom of the liquid.
Which suspension is best flocculated or Deflocculated?
INTRODUCTIONFlocculated suspensionDeflocculated suspensionSediment is loosely packed and does not form a hard cake.Sediment is tightly packed and forms a hard cake.The supernatant is clear.The supernatant is hazy.Floccules stick to the sides of the bottle.Particles do not stick to the sides of the bottle.4 more rows
Which is the most stable pharmaceutical suspension?
flocculated suspensionflocculated suspension the loose structure of the rapidly sedimenting flocs tends to preserve in the sediment, which contains an appreciable amount of entrapped liquid. The volume of final sediment is thus relatively large and is easily redispersed by agitation. Most stable pharmaceutical suspensions are flocculated.
Is flocculated suspension more stable?
Particle size This means that a suspension that is smaller in particle size will be more stable. When particle-particle interaction occurs, it results in floccules or coagulates, increasing sedimentation.
What is difference between flocculated and Deflocculated suspension?
The key difference between flocculation and deflocculation is that flocculation is the formation of flocs by the clumping of fine particles whereas deflocculation is the dispersion of flocs to form a stable colloid.
Why flocculated suspension is more stable than Deflocculated?
A deflocculated system has an advantage in that their sedimentation rate is slow, thereby allowing uniform dosing. However, if settling occurs, the sediment can be compact and difficult to redisperse. On the other hand, flocculated suspensions are stilted because the particles separate quickly.
Why sedimentation rate of flocculated suspension is faster than Deflocculated suspension?
Floccules can sediment faster than smaller particles under the effect of gravity. The sediment formed in a flocculated suspension is larger than expected because the floccules have a loose structure with pores and these pores can entrap liquid. Therefore the volume of the final sediment is larger than expected.
Which suspension has more void?
Answer. Hence, flocculated suspensions sediment more rapidly.
Which is the method for stability of suspension?
Abstract. Suspension stability can be theoretically estimated prior to the beginning of the formulating process based on the solid phase particle size, liquid phase density, and viscosity. Stokes equation can be used to predict suspension stability in order to save time and resources.
How do you make a suspension more stable?
There are some useful methods to improve the physical stability of a suspension, such as decreasing the salt concentration, addition of additives to regulate the osmolarity, as well as changes in excipient concentrations, unit operations in the process, origin and synthesis of the drug substance, polymorphic behavior ...
Why suspended particles become flocculated in a suspension?
Answer: Ionic surfactants cause flocculation by neutralizing the charge on each particle, resulting into a flocculated suspension. When the surfactants reduce the interfacial tension, the liquid becomes capable of displacing the adsorbed film of air from the surface of solid drug particle and facilitating wetting.
What is the meaning of flocculation?
Definition of flocculation n. The process of becoming flocculent. Precipitation from solution in the form of fleecy masses.
What is flocculated and non flocculated suspension?
The suspension are said to be flocculated ,when the individual particles are in contact with each other and form a network like structure . Whereas in case of non-flocculated suspensions,the individual particles exists as a separate entity.
What is a stable suspension?
Suspension stability can be theoretically estimated prior to the beginning of the formulating process based on the solid phase particle size, liquid phase density, and viscosity. Stokes equation can be used to predict suspension stability in order to save time and resources.
What is pharmaceutical suspension?
A pharmaceutical suspension is a coarse dispersion of insoluble solid particles in a liquid medium. The particle diameter in a suspension is usually greater than 0.5 µm. However, it is difficult and also impractical to impose a sharp boundary between the suspensions and the dispersions having finer particles.
How do you make a suspension more stable?
There are some useful methods to improve the physical stability of a suspension, such as decreasing the salt concentration, addition of additives to regulate the osmolarity, as well as changes in excipient concentrations, unit operations in the process, origin and synthesis of the drug substance, polymorphic behavior ...
What is better for a pharmaceutical a solution or suspension?
The only real difference in administering these medications is that you must shake a suspension to evenly distribute the product before administering, but you do not need to shake a solution because the product is already evenly distributed due to being dissolved in the solvent (though there are suspensions with other ...
What is the difference between flocculated and deflocculated suspensions?
1. The particles of dispersed phase aggregate and form a loose networklike structure. The particles of the dispersed phase remain as separate entities. 2.
What determines if a suspension is flocculated or deflocculated?
Whether a suspension is flocculated or deflocculated depends on the relative magnitudes of the electrostatic forces of repulsion and the forces of attraction between the particles.
Why is the interparticle interaction in compact sediments relatively high?
The interparticle interaction in such compact sediments is relatively high because the interparticle distances are small, leading to the undesirable phenomenon of caking , a tightly packed sediment that was almost impossible to resuspend even with vigorous shaking.
Why are aggregates redispersible?
In this suspension type, the structure of the aggregates is quite rigid; hence they settle quickly to form a high sediment height and are easily redispersible because the particles constituting individual aggregates are sufficiently far apart from one another to preclude caking.
What is the name of the suspension of particles?
Such a suspension is called flocculated suspension.
What is the repulsive barrier?
A repulsive barrier termed the primary maximum, separates the secondary minimum from the primary minimum. The magnitude of the repulsive forces at the primary maximum determines whether a flocculated system will remain flocculated.
What is the term for the formation of a loose aggregation of discrete particles held together in a?
Flocculation refers to the formation of a loose aggregation of discrete particles held together in a network like structure by physical adsorption of macromolecules when the longer-range van der Walls forces of attraction exceed the shorter-range forces of repulsion.
What is flocculated suspension?
A flocculated suspension is a suspension in which particles of the suspension has undergone flocculation. A flocculated suspension is composed of large aggregates (flocks) and this type of suspension will lead to a rapid rate of sedimentation.
What is a suspension in medical terms?
Suspensions are a class of dispersed systems (Heterogenous systems) in which a finely divided solid is dispersed uniformly in a liquid dispersion medium. or A pharmaceutical suspension may be defined as a coarse dispersion of biphasic liquid dosage form containing finely divided insoluble material suspended in a liquid medium.
What are the two groups of suspensions?
Suspensions can be divided into two groups as flocculated suspensions and deflocculated suspensions based on the electro-kinetic nature of solid particles that are suspended in the suspension.
Why is suspension used in parentral application?
Suspension can be formulated for parentral application in order to control rate of drug absorption.E .g. penicillin procaine
What is the purpose of oxy tetracycline suspension?
To prevent degradation of drug or to improve stability of drug; E.g. Oxy tetracycline suspension
What is a pharmaceutical suspension?
A pharmaceutical suspension is a coarse dispersion in which the internal phase (the active ingredient) is placed/distributed uniformly throughout the external phase/continuous phase.
Where is suspension given?
Suspension dosage forms are given by the oral route, injected intramuscularly or subcutaneously, instilled intranasally, inhaled into the lungs, applied to the skin as topical preparations, or used for ophthalmic or otic purposes in the eye or ear, respectively.
What is Flocculation?
Flocculation is the formation of clumps by the aggregation of fine particles in a suspension. These clumps are called flocs or flakes. Flocculation may occur spontaneously or due to the addition of a clarifying agent. However, this floc formation is different from precipitation. It is because, in precipitation, dissolved components form a solid while in flocculation, undissolved components form a solid.
What is the opposite of flocculation?
These clumps are called flocs. We mainly use this term regarding suspensions. Deflocculation, on the other hand, is the opposite of flocculation.
What is floc dispersion?
Deflocculation is the dispersion of flocs in a suspension. Deflocculants can make this happen by increasing zeta potential (the potential difference existing between the surface of a solid particle immersed in a conducting liquid (e.g. water) and the bulk of the liquid) and the repulsive forces between particles.