A successfully developed generic drug product is expected to be:  pharmaceutically equivalent to its reference listed drug (RLD), bioequivalent to the RLD, and, consequently, therapeutically equivalent. Studies to establish bioequivalence are conducted both in vivo and in vitro. In vitro bioequivalence studies are recommended for non-absorbed drugs, topical drugs, locally acting emulsions and suspensions, as well as multi-strength product equivalency.

As of the December 2017 Immediate-Release Solid Oral Dosage Form Guidance for Industry issued by the FDA, the biowaiver for in vitro bioequivalence testing was extended to those immediate release solid oral dosage forms that are either BCS class 1 or BCS class 3. This allows for establishing bioequivalence via comparative dissolution for both the test and reference products in various pH-adjusted media. Replicate dissolution via USP Apparatus 1 or 2 is employed for this.

AMRI provides cGMP dissolution support for APIs and a wide variety of dosage forms in various media systems, including biorelevant media. We have capability with various USP dissolution apparatus options, along with various diffusion experiments, using a variety of chromatographic and spectroscopic detection techniques. Our experience in comparative dissolution, combined with our expertise in solid-state chemistry, positions us well for in vitro bioequivalence testing of various drug products.


AMRI has a wide variety of dissolution and related instrumentation to support in vitro bioequivalence testing, including:

  • USP Dissolution
    • Apparatus 1
    • Apparatus 2
    • Apparatus 5
  • Diffusion
    • Franz vertical diffusion cells
    • Side-by-side diffusion cells
  • Chromatography
    • HPLC, UPLC, Ion Chromatography (IC), and Size Exclusion (SEC)
    • Detection by UV, MS, RID, MALS, CAD, and Fluorescence
  • Spectroscopy
    • UV-Vis
    • Fluorescence

In Vitro Bioequivalence Pilot Studies

When developing new generic formulations, pilot studies for in vitro bioequivalence evaluation of products or formulations can be extremely helpful to aid the development process, and verify that a formulation is ready to move forward, or to screen various potential formulations. From simple dissolution to complex sample preparation evaluation, our scientists have the expertise to help screen your products to keep them progressing through their development lifecycle.

More Information

Draft Guidance for Industry on Bioequivalence Studies

Waiver of In Vivo Bioavailability and Bioequivalence Studies for Immediate-Release Solid Oral Dosage Forms Based on a Biopharmaceutics Classification System Guidance for Industry

AMRI provides cGMP support for dissolution and related techniques to meet the FDA requirements for in vitro bioequivalence testing of a variety of dosage forms. Combined with an excellent regulatory record, AMRI is the clear choice for a partner in testing for approval of new generic drug products requiring in vitro bioequivalence testing.