## What is Higuchi equation?

The Higuchi’s equation , also called square-root law according to Higuchi referred to , describes the release of a uniformly in an insoluble matrix suspended substance by diffusion . Takeru Higuchi published it in 1961 to characterize the release of medicinal substances from suspension ointments.

## What is korsmeyer Peppas model?

Korsmeyer-Peppas was a simple model known as “Power law” describing drug release from a polymeric system. Korsmeyer-Peppas model (1) describe some release mechanisms simultaneously such as the diffusion of water into the matrix, swelling of the matrix and dissolution of the matrix [12].

**How do you calculate the n value in korsmeyer Peppas model?**

Take “ln” on both sides of the equation. Then your equation would be ln(Mt/Mi) = ln (k) + n*ln (t).

**How is drug release kinetics calculated?**

The fundamental principle for evaluation of the kinetics of drug release was offered by Noyes and Whitney in 1897 as the equation (10): dM/dt = KS (Cs с Ct) (1) where M, is the mass transferred with respect to time, t, by dissolution from the solid particle of instanta- neous surface, S, under the effect of the …

### What is Higuchi release kinetics?

Simplified Higuchi model describes the release of drugs from insoluble matrix as a square root of time dependent process based on Fickian diffusion Equation. Q = KH t1/ 2. The data obtained were plotted as cumulative percentage drug release versus square root of time.

### What is the ritger Peppas equation?

The previously (Ritger and Peppas, 1987) introduced exponential relation Mt/M∞ = ktn may be used to describe the Fickian and non-Fickian release behavior of swelling-controlled release systems which swell to a moderate equilibrium degree of swelling and are prepared by incorporation of a drug in a hydrophilic.

**Which equation is used in the mathematical Tretament of in vitro drug dissolution?**

To study the dissolution from a planar heterogeneous matrix system, where the drug concentration in the matrix is lower than its solubility and the release occurs through pores in the matrix, the expression is given by equation: ft = Q = √Dδ/τ (2C- δCs) t ——————–(16) Where, D is the diffusion coefficient …

**How do you calculate cumulative release?**

Put the absorbance data of the samples (collected at predetermined time) into the standard curve of the drug. Then divide the obtained value to total amount of the drug encapsulated in the NPs and multiply with 100, you will obtain cumulative drug release at that time interval.

## What does Fick’s law state?

Fick’s law states that the rate of diffusion of a substance across unit area (such as a surface or membrane) is proportional to the concentration gradient.

## How do you calculate drug release in dissolution?

Amount of drug released mg/ ml = Concentration × Dissolution bath volume × dilution factor/1000.

**How do you calculate release?**

**What is Fick’s first law of diffusion equation?**

Fick’s first law of diffusion is given by the following equation: J=−Ddcdx. where. 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. The units of J are mol m-2 s-1.

### Which one of these is an example of Fick’s first law in action?

Which one of these is an example of Fick’s First Law in action? Dropping a drop of food coloring into a glass of water and watching it spread out.

### What is the formula of Dilution factor?

A dilution factor is the total volume of a sample plus diluent after dilution divided by the inital volume of sample. 100 mL of final volume ÷ 2 mL original volume of sample = 50 dilution factor.

**How do you calculate f1 and f2 in dissolution?**

The factor f1 is proportional to the average difference between the two profiles, where as factor f2 is inversely proportional to the average squared difference between the two profiles, with emphasis on the larger difference among all the time-points. The factor f2 measures the closeness between the two profiles.

**What is f1 and f2 factor in dissolution?**

The fit factors can be expressed by two approaches: f1 (the difference factor) and f2 (the similarity factor). Two dissolution profiles to be considered similar and bioequivalent, f1 should be between 0 and 15 whereas f2 should be between 50 and 1006.

## How do you calculate final dilution?

Use the formula: Final DF = DF1 * DF2 * DF3 etc., to choose your step dilutions such that their product is the final dilution.

- Example: Make only 300 μL of a 1:1000 dilution, assuming the smallest volume you can pipette is 2 μL.
- Choose step DFs: Need a total dilution factor of 1000.