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In terms of stability, particle size has a direct effect on the ease of maintenance of a uniform suspended phase. Reducing the size of suspended drug particles therefore reduces the rate and likelihood of sedimentation, helping to maintain the dispersion.
Why is particle size important in suspension?
When a suspension is very well dispersed (i.e., deflocculated), the particles will settle as small individual particles. Particle size of the active agent plays a key role in the physical stability and bioavailability of the drug product. The rate of sedimentation, agglomeration, is affected by particle size.
How will you maintain stability of suspension?
Particle radius (a) will have a large bearing on suspension stability. To maintain stability through Brownian motion we need to prevent particles sticking when they collide. This can be achieved by increasing the charge associated with the particle i.e. zeta potential.
What are suspension properties?
Suspension is a heterogeneous Mixture. The particles of a suspension can be seen by the naked eye. The particles of a suspension scatter a beam of light passing through it and make its path visible. The solute particles settle down when a suspension is left undisturbed, that is, a suspension is unstable.
Which cation is most stable?
(CH3)3C+3∘ carbonium ion is most stable.
Is suspension can improve the chemical stability of a drug?
Suspension can improve chemical stability of certain drug. For example Procaine penicillin G. Drug in suspension exhibits higher rate of bioavailability than other dosage forms. Suspension can mask the unpleasant/bitter taste of drug.
Which agents are used for stability of suspension?
Xanthan gum in drug delivery applications XG is widely used as a suspending agent and stabilizer in suspension due to its safety properties in food and drug applications. Moreover, it is soluble in water and can provide sufficient viscosity in low concentration.
What is a suspension Class 9?
Suspension is the heterogeneous mixture of two or more substances. In suspension, particles are suspended throughout in bulk and can be seen by naked eyes. Particles of suspension are large enough to scatter rays of light and path of ray is visible through a suspension.
What is D90 particle size?
D50: The portions of particles with diameters smaller and larger than this value are 50%. Also known as the median diameter. D90: The portion of particles with diameters below this value is 90%.
Which suspension is more stable and why?
Suspension is more stable. This is because suspension does not mix with each other. The denser particles settle down at the bottom and makes the solution stable.
What is the importance of particle size for powders in general?
Why is Particle Size Distribution Important? Tightly controlled particle size distributions are highly important for pharmaceutical drug development. Powder particle size distribution is a valuable indicator of quality and performance.
Which is the correct order of stability of solution?
Question : The correct order of stability is Inert pair effect.
Is a true solution stable?
(i) A true solution (or simply a solution) is a homogeneous mixture. That is in a true solution, the solute and solvent molecules cannot distinguish even under microscope. (vi) The solute particles in a true solution do not settle down.
Which one of properties is applicable to suspension?
The properties of suspension are listed below. A suspension is a heterogeneous solution in which, while standing, several particles move out of the mixture. In a suspension, the volume of the solvent particles is quite high. It has a length of more than 100 mm.
What is the reason why we need to formulate suspension?
The reasons for the formulation of a pharmaceutical suspension: — when the drug is insoluble in the delivery vehicle. –To mask the bitter taste of the drug. –To increase drug stability.
How suspension improves the stability of drugs?
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 the particle size of suspension?
Difference between Colloid and Suspension
| Suspension | Colloid |
|---|---|
| Particle size greater than 1000 nm | Particle size range from 1 and 1000 nm |
| Particles settle down well | Particles do not separate |
| Can be separated by filtration | Cannot be separated by filtration |
| May scatter light | Shows Tyndall effect (scatters light) |
How does particle size affect drug stability?
A product with a smaller, more uniform particle size is more stable and less likely to separate out. This translates to a longer shelf life and less waste.
How do you evaluate suspension?
Prepared suspension were evaluated by studying different parameters like pH, sedimentation volume, redispersibility, Flow rate (F), viscosity, degree of flocculation, effect of temperature etc.
What are the advantages of suspension?
The following advantages can be obtained by formulating API as a suspension dosage form.
- Suspensions are a useful drug delivery system for therapeutic agents that have a low solubility.
- Pharmaceutical suspensions may be formulated to mask the unpleasant/ bitter taste of drug.
What are 3 types of suspension?
There are three basic types of suspension components: linkages, springs, and shock absorbers.
What is a suspension formulation?
Pharmaceutical suspensions are liquid dosage forms containing finely divided insoluble materials (the suspensoid) distributed somewhat uniformly throughout the suspending medium (suspending vehicle) in which the drug exhibits a minimum degree of solubility.
What are the roles of suspending agents in suspension stability?
Suspending agents form film around particle and decrease interparticulate attraction. At rest the solution is sufficient viscous to prevent sedimentation and thus aggregation or caking of the particles. When agitation is applied the viscosity is reduced and provide good flow characteristic from the mouth of bottle.
How do you analyze particle size distribution?
The most common techniques to determine particle size distribution are dynamic image analysis (DIA), static laser light scattering (SLS, also called laser diffraction), dynamic light scattering (DLS) and sieve analysis.
What is the stability of 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. In order to prevent formation of the solid sediment, controlled flocculation of the suspended bismuth subnitrate particles is recommended.
What is the major stability problem related to the suspension?
The main problem dealt with in this article is preventing the aggregation of particles in a suspension — extensive aggregation can lead to ‘caking’. This is the process in which almost all particles in the sediment become interconnected, making it impossible to resuspend.
How will you differentiate between a suspension and a colloid?
A colloid is a heterogeneous mixture in which the dispersed particles are intermediate in size between those of a solution and a suspension.Colloids.
| Solutions | Colloids | Suspensions |
|---|---|---|
| Do not separate on standing | Do not separate on standing | Particles settle out |
