Differbetween
The main difference between Fickian and Non Fickian Diffusion is that Fickian diffusion obeys the Fickian laws whereas non Fickian diffusion does not obey the Fickian laws.
- What is fickian and non-fickian diffusion?
- What is quasi fickian diffusion?
- What is flux in diffusion?
- What is Super Case II transport?
- What is Higuchi model in drug release?
- What is Fick's second law of diffusion?
- What is release profile?
- What is zero order drug release?
- How do you calculate release kinetics?
- What are the 3 types of diffusion?
- Why is Fick's Law negative?
- What is the diffusion rate?
What is fickian and non-fickian diffusion?
Fickian diffusion refers to the solute transport process in which the polymer relaxation time (tr) is much greater than the characteristic solvent diffusion time (td). When tr ≈ td, the macroscopic drug release becomes anomalous or non-Fickian [3].
What is quasi fickian diffusion?
release, where a value of 0.43 or below 0.43 for sphere suggests diffusion controlled release. 8. (Fickian diffusion or quasi-Fickian diffusion), while a value of between 0.43 and 0.89 for sphere. 9. suggests anomalous diffusion or non-Fickian diffusion.
What is flux in diffusion?
Fick's First Law of Diffusion
J is the flux and is defined by the number or particles that are moving past a given region divided by the area of that region multiplied by the time interval.
What is Super Case II transport?
Fickian transport refers to the interdiffusion of penetrant and polymer described by Fick's equations. ... Ideally, this sharp boundary moves through the polymer at a constant velocity during Case II transport.
What is Higuchi model in drug release?
Higuchi model is given by the equation: ft = Q = A√ where, Q is the amount of drug released in time t per unit area A, C is the drug initial concentration, Cs is the drug solubility in the matrix media and D is the diffusivity of the drug molecules (diffusion coefficient) in the matrix substance.
What is Fick's second law of diffusion?
Fick's 2nd law of diffusion describes the rate of accumulation (or depletion) of concentration within the volume as proportional to the local curvature of the concentration gradient.
What is release profile?
5.1 Drug release profile. The drug release profile is a key factor in the performance of a DES [71]. ... Put simply, the optimal drug release profile will be one that ensures that the arterial wall concentrations of the drug are maintained at the therapeutic dose within the target cells for the period required.
What is zero order drug release?
Zero order release kinetics refers to the process of constant drug release from a drug delivery device such as oral osmotic tablet, transdermal system, matrix tablet with low soluble drugs and other delivery system. Constant release is defined in this context as the same amount of drug release per unit time.
How do you calculate release kinetics?
Zero order model [5]: According to the principles of pharmacokinetics, drug release from the dosage form can be represented by the equation: C0-Ct =K0t Ct=C0 +K0t Ct is the amountof drug released at time t, C0 is the initial concentration of drug at timet=0, K0 is the zero-order rate constant.
What are the 3 types of diffusion?
1 Answer. Simple diffusion, osmosis and facilitated diffusion.
Why is Fick's Law negative?
The local rule for movement or flux J is given by Fick's 1st law of diffusion: ... The negative sign indicates that J is positive when movement is down the gradient, i.e., the negative sign cancels the negative gradient along the direction of positive flux.
What is the diffusion rate?
rate of diffusion=amount of gas passing through an areaunit of time. The diffusion rate depends on several factors: the concentration gradient (the increase or decrease in concentration from one point to another); the amount of surface area available for diffusion; and the distance the gas particles must travel.
