What is intra subject variability in bioequivalence?

Intra-subject variability (CVintra), which determines the 90% confidence intervals and the number of subjects needed for assessment in bioequivalence studies, is generally investigated by using pilot study Results. However, conducting pilot studies greatly affects the speed and cost of drug development.

What are the 2 types of bioavailability?

Types of bioavailability are as follow:

  • Absolute Bioavailability: When the drug is administered through the intravenous route, the bioavailability of the drug achieved will be 100 percent.
  • Relative Bioavailability: It is the bioavailability of the drug when obtained and it is compared with a reference standard.

When bioavailability and bioequivalence studies are carried out?

Bioequivalence studies are special type of studies where two drugs or two sets of formulation of the same drug are compared to show that they have nearly equal bioavailability and PK/PD parameters. These studies are often done for generic drugs or when a formulation of a drug is changed during development.

What’s the difference between drug product performance and bioequivalence?

Bioequivalence studies are drug product performance tests that compare the bioavailability of the same active pharmaceutical ingredient from one drug product (test) to a second drug product (reference). Bioavailability and bioequivalence can be considered as measures of the drug product performance in vivo.

What is intra and inter subject variability?

Variability can be seen at many levels: intra-subject refers to the difference found in the same subject in multiple repetitions of the same task [1]. Inter-subject variability refers instead to the variation of motor patterns when multiple subjects repeat the same motion [2,3].

How do you calculate intra-subject variability?

Intra-subject CV is then calculated using CV=100*sqrt(exp(MSE)-1).

How is bioequivalence determined?

Bioequivalence is determined based on the relative bioavailability of the innovator medicine versus the generic medicine. It is measured by comparing the ratio of the pharmacokinetic variables for the innovator versus the generic medicine where equality is 1.

What phase is a bioequivalence study?

Bioavailability and bioequivalence studies are routinely conducted in a small number of subjects in Phase 1 CRUs and reported according to strict regulations.

What is drug bioavailability?

Bioavailability refers to the extent a substance or drug becomes completely available to its intended biological destination(s).

What is the bioequivalence variability for generic drugs?

The products are considered bioequivalent if the 90% confidence intervals for the ratio (generic/innovator) of the means of Cmax and AUC are within the range 0.80-1.251. The 0.80-1.25 acceptance range accounts for statistical error and is internationally considered to be clinically insignificant2,3.