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IVRT: A cost-effective study that fulfills dermatological bioequivalence testing requirements

Updated: Jul 2

Recent updates in FDA guidelines open a cost-saving opportunity for pharma companies looking to fulfill dermatological bioequivalence testing requirements

In the last few years, the FDA has updated some of its guidelines to accept innovative bio-equivalence testing approaches for topical formulations. In 2022, the FDA started accepting In Vitro Release Test (IVRT) studies as the fulfillment of dermatological bioequivalence testing requirements. This move from in vivo clinical endpoint studies to in vitro studies is a market opportunity for small to medium pharmaceutical companies that find the cost of clinical studies to be too steep.

What is IVRT?

An In Vitro Release Test (IVRT) is a study that estimates the steady state rate of an active pharmaceutical ingredient (API) release from a semisolid formula to analyze the product quality. Also known as the Franz Cell Test, it imitates how APIs act when applied to human skin.

In IVRT, a test sample is placed on a membrane. The rate of API release is estimated by collecting the permeate on the back of the membrane. IVRT has become a fundamental tool in drug development and product equivalence analysis.

In the case of The J. Molner Company, our laboratory can perform IVRT studies that are FDA-compliant for generic dermatological formulations. We offer clients IVRT study services that are less time-consuming and expensive than in vivo studies.

Is IVRT the same as IVPT?

No, they are totally different. While IVRT focuses on the API release, the In Vitro Permeation Test (IVPT) estimates the formula’s permeability. Here are some other key differences between these two methods:



Measures release Offers relative consistency Uses synthetic membrane Product/media interface Formulation specific Occluded dose Pseudo infinite dose Tracks release rate Hydro-alcoholic media μg to mg range

Measure permeation Offers donor variability Uses human skin Product remains dry IVIV Correlation Unoccluded dose Finite dose Tracks flux profile Physiological media pg to ng range.

Partnering up: the key to safe and accurate IVRT studies

The traditional design of an In Vitro Release Test (IVRT) has the following characteristics:

  • Uses Franz Cell Testing to evaluate and compare two samples: one of them being the Reference product and the other being the Test.

  • Its main objective is to determine the equivalence between the API release rate of the Test sample against the Reference.

  • Estimates the API’s rate of release to analyze the product features and how they can affect the performance of the formulation.

Beyond fulfilling the bioequivalence testing requirements set by the FDA, IVRT can be used to track product conformity in stability studies and analyze continuous batch release. In addition, it can be used after regulatory approval to analyze the quality of manufacturing and measure changes in excipient grades and amounts.

Pharmaceutical companies now can shorten their testing cycles by partnering with laboratories that have highly motivated teams with years of experience. By choosing a partner to fulfill IVRT testing requirements, pharmaceutical companies can focus on research while keeping the approval pipeline going without having to invest heavily in clinical trials.

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