Bioequivalence

The term comes from the pharmacokinetics and bioequivalence assess the interchangeability of two drug- drug equivalent, but differ in the manufacturing process and / or the excipients contained.

Definition

Two drugs is referred to as bioequivalent if within a 90 % confidence interval for bioavailability equal to 80 to 125%. The extent and the rate of pharmaceutical substance are compared. In bioequivalent drugs, it is assumed that an exchange between the two drugs can take place without danger to the patient. The problem, however, such an exchange is in drugs with a narrow therapeutic index. Theophylline, thyroxine or digitoxin are those drugs.

The test for bioequivalence is carried out by means of a pharmacokinetic study in volunteers. Two groups received under strictly standardized conditions, an equal dose of the test drug or the reference product. At specified time intervals, blood samples are taken and analyzed for drug concentration back.

Mathematical parameters against which the bioequivalence can be assessed, for example, the area under the plasma concentration-time curve ( area under the curve (AUC ) (see trapezoidal rule ) ) or peak plasma concentrations (Cmax ). Another characteristics of the time of occurrence of peak plasma levels (Tmax ), the minimum plasma concentrations ( Cmin ) and the delay time of absorption ( TLag ) apply.

When referring to it drug approvals, which are usually applied for and granted for generics, ask the competent authorities of the claimant to show bioequivalence to the original product of the first-mover. The 90 - % confidence interval ( CI ) of the ratio of the needs for the identified parameters for comparative average values ​​for the test product and reference product are within a defined limits (usually are 80-125 %). The selection of parameters and the study design depend inter alia on the indication and the dosage form of the drug.

• Pharmacy
• Clinical Research