What is IVRT & IVPT?

What Are IVRT And IVPT Studies?

IVRT and IVPT using Franz-type diffusion Cells for topical and transdermal products have been a key focus in developing both generic and branded products. IVRT studies aid in determining how the drug is released from the formulation, whereas IVPT studies assess how well the drug permeates through human skin.

The FDA has issued specific bioequivalence guidances for over 75 products, requiring either IVRT studies or IVRT and IVPT studies for generic products. FDA also provides general guidance on IVRT and IVPT methodologies that should be followed during bioequivalence development, validation, and conduct. Healios possesses extensive experience in conducting bioequivalence studies involving generic products through IVRT and IVPT studies.

IVRT and IVPT studies are an important part of the development of novel topical & transdermal products, especially in the selection if new chemical entities, dosage form selection and formulation development. Employing these in vitro techniques throughout product development significantly conserves time, resources, and expenses. Healios has substantial experience in conducting IVPT studies employing various skin membranes, such as stratum corneum, epidermis, and dermis, and in the receiver phase.

Feature	IVRT	IVPT
Purpose	Measures drug release from a formulation.	Measures drug permeation through biological skin.
Membrane Used	Synthetic membrane.	Human or animal skin.
Primary Use	Formulation development and quality control.	Bioequivalence and skin absorption studies.
Regulatory Value	Supports formulation performance.	Supports regulatory submissions.

Our Stellar score card for IVRT-IVPT studies:

Trusted Experience. Proven Results.

20+

Years of Team Experience

30+

IVRT Studies Conducted for Generic and New Drug Products

10+

IVPT Studies Conducted for Generic and New Drug Products

10+

Regulatory Submissions to USFDA

20+

IVRT / IVPT Methods Developed and Validated Using Logan Platform

20+

Analytical Methods Developed and Validated Using HPLC Platform

10+

Projects Approved by Regulatory Agencies

Full-Service Expertise: From Idea to Approval

✔Method development & validation

✔Skin procurement and barrier verification

✔Franz cell qualification & experimental execution

✔Analytical method development (HPLC, LC-MS/MS)

✔Mass balance & skin retention studies

✔Statistical analysis (Mann-Whitney, AUC, flux comparison)

✔Regulatory dossier support for ANDA / NDA / 505(b)(2)

IVRT & IVPT Applications Tailored to Every Stage of Development.

✔Formulation optimization

✔BE studies (ANDA, 505(b)(2))

✔Post-approval changes

✔Safety testing: irritation, clearance

✔Clinical de-risking and early-stage R&D

✔IP showcase and investor pitches

✔Comparative performance studies

Comprehensive Expertise Across Topical and Mucosal Dosage Forms

Our team possesses extensive hands-on expertise with both Franz Cell and Enhanced Diffusion Cell systems, supporting a broad spectrum of formulation types including semisolids, pulmonary, and rectal/vaginal dosage forms. We have successfully executed studies across various administration routes—Topical, Sublingual, Buccal, Ophthalmic, Vaginal, and Rectal—demonstrating our versatility in handling diverse product categories. Our laboratory routinely utilizes a wide array of membrane types, including synthetic polymers, biomimetic barriers, and biological tissues such as human and porcine skin, ensuring physiologically relevant permeation models for each project.

Dosage Forms We Support

✔Creams

✔Ointments

✔Lotions

✔Suspensions

✔Gels

✔Hydrogels

✔Pastes

✔Pump Sprays

✔Topical Aerosols

✔Foams

✔Patches

✔Nail Lacquers

✔Ophthalmic semisolids

✔Suppositories

Expert Method Development & Validation for IVRT and IVPT Studies

Your topical drug development program requires precision, reproducibility, and regulatory confidence.
At Healios Labs, we provide expert method development and validation for In Vitro Release Testing (IVRT)
and In Vitro Permeation Testing (IVPT) studies, generating robust, defensible data to support global
regulatory submissions.

A Customised, Science-Driven Approach

We view method development as a precision-engineered process, not a one-size-fits-all exercise.
Every protocol is custom-designed based on:

✔API physicochemical properties

✔Formulation complexity and excipient interactions

✔Intended reference product behavior

✔Regulatory expectations for bioequivalence

This tailored approach ensures methods that are reproducible, discriminatory, and fit-for-purpose
across development and regulatory stages.

Key Method Development Capabilities

We establish a strong and reliable foundation for IVRT and IVPT studies by optimizing critical parameters:

Custom Membrane Selection

Selection of appropriate synthetic or biological membranes, including human and porcine skin,
to accurately reflect drug release and permeation behavior.

Receptor Media Optimization

Development of customized receptor media to maintain sink conditions, API solubility,
and chemical stability throughout the study duration.

Franz Diffusion Cell Qualification

Comprehensive IQ / OQ / PQ qualification of Franz diffusion systems in alignment with FDA
and EMA expectations.

Discriminatory Method Design

Development of highly sensitive methods capable of detecting subtle formulation differences,
critical for demonstrating generic bioequivalence under 21 CFR 320 and SUPAC-SS guidance.

Rigorous Method Validation for Regulatory Confidence

Our validation strategy ensures your method delivers accurate, reliable, and defensible data.
Validation is performed in accordance with ICH and FDA guidelines, covering all critical
performance attributes.

We rigorously evaluate:

✔Accuracy and precision (intra- and inter-day)

✔Linearity and reproducibility

✔Specificity and selectivity

✔Picogram-level sensitivity for low-dose APIs

✔Method robustness under variable conditions

✔Discriminatory power between test and reference formulations

All methods are validated to align with FDA Draft IVRT Guidance, USP <724> / <1724>,
EMA Draft Guideline, and OECD Test Guideline 428, ensuring readiness for global regulatory submissions.

Advanced Bioanalytical Capabilities

Our state-of-the-art bioanalytical platform enables accurate quantification of ultra-low
concentrations in IVRT and IVPT samples, even for challenging molecules.

Analytical technologies include:

✔LC–MS/MS for picogram-level sensitivity

✔HPLC for robust quantitative analysis

✔UV–Visible spectrophotometry for complementary testing

These capabilities ensure high-fidelity, reproducible data across a wide range of APIs
and formulations.

Skin Integrity Assessment & Permeation Analysis

For IVPT studies, we employ advanced skin integrity and barrier function assessments
to ensure data reliability:

✔Transepidermal Water Loss (TEWL) testing

✔Electrical impedance measurements

✔Our comprehensive IVPT analysis includes:

✔Cumulative permeation profiling

✔Flux and lag time determination

✔Skin retention analysis

✔Mass balance studies

Together, these evaluations provide a complete and regulatory-compliant understanding
of topical drug permeation behavior.

Adhering to Global Regulatory Guidelines (FDA, EMA, ICH, etc.)

Regulatory Guidelines & Standards

FDA Guidelines

✔FDA Guidance for Industry: Topical Dermatological Drug Products – In Vitro Release Testing (IVRT)

✔FDA Guidance for Industry: Bioequivalence Recommendations for Topical Dermatological Products

✔FDA Guidance: In Vitro Permeation Testing (IVPT) for Transdermal and Topical Products

EMA Guidelines

✔EMA Guidelines on Bioequivalence of Topical Products (including IVRT / IVPT as part of the overall testing strategy)

✔EMA Committee for Medicinal Products for Human Use (CHMP) Guidelines on the Development of Topical Products

✔EMA Guideline on the Evaluation of Bioequivalence of Transdermal Patches

ICH Guidelines

✔ICH E6 (R2) Good Clinical Practice – This guideline addresses clinical trials, but it often intersects with IVRT / IVPT as part of the product development process for topical and transdermal systems.

United States Pharmacopeia (USP)

✔USP General Chapter <1724> Transdermal Drug Delivery Systems – In Vitro Testing

✔USP General Chapter <724> In Vitro Release Testing of Topical Drug Products

WHO Guidelines

WHO Guidelines on the Evaluation of Medicines for Use in the Treatment of Human Diseases
(which includes IVRT for topical products as part of drug evaluation)

OECD Guidelines

✔OECD Test Guideline 428

Quality Assurance Oversight for IVRT & IVPT Studies

Quality, Compliance & Inspection Readiness

Healios Labs is a US FDA-registered analytical facility with a valid Facility Establishment Identifier (FEI). We are fully inspection-ready for both regulatory agency and client-sponsored GMP/GLP inspections. Our commitment to quality is overseen by an independent Quality Assurance (QA) unit, led by a professional with over 15 years of domain-specific experience in GxP environments, particularly in topical bioequivalence studies. Our QA head has successfully managed multiple FDA pre-approval inspections (PAI) and routine GMP surveillance audits, ensuring continuous compliance with 21 CFR Part 210/211, 21 CFR Part 58 (GLP), and all applicable EMA/ICH guidelines.

Quality Management System

All phases of our IVRT and IVPT studies—from method development and validation to data reporting and archiving—are governed by a robust suite of internally validated Standard Operating Procedures (SOPs). These SOPs are meticulously version-controlled, training-qualified, and regularly reviewed under a formal change control system in accordance with ICH Q10 Pharmaceutical Quality System (PQS).

Facility & Data Integrity

Our facility has been meticulously designed to meet stringent GMP and GLP standards. It incorporates dedicated IVRT/IVPT study zones with a unidirectional workflow to minimize cross-contamination risks.

✔Dedicated IVRT/IVPT study zones with unidirectional workflow

✔Installation, Operational, and Performance Qualification (IQ/OQ/PQ) under QA oversight

✔21 CFR Part 11-compliant electronic systems

✔Full audit trail functionality

✔Total data integrity and traceability

✔Compliance with the most stringent regulatory requirements

Furthermore, all critical study data—both raw and processed—is meticulously managed and securely archived using 21 CFR Part 11-compliant electronic systems. These systems feature full audit trail functionality and are designed to guarantee total data integrity and traceability, meeting the most stringent regulatory requirements.

Our Team for IVRT & IVPT Studies

Scientific Leadership

Lead Scientific Investigator – Dr Lakshmi Raghavan.

Role: Principal Scientific Investigator – IVRT & IVPT, Healios Labs

Experience: 25+ years in topical and transdermal drug delivery

Key Expertise & Contributions

✔Expertise in formulation science, regulatory strategy, and bioequivalence

✔Development of 35+ dosage forms across semisolids, ophthalmics, injectables, and transdermals

✔Specialization in Q1 / Q2 formulation sameness and Q3 microstructure equivalence

✔Design and submission of 18+ FDA / EMA-compliant IVRT and IVPT studies

✔4 topical generics approved based solely on IVPT without clinical endpoint studies

✔Deep understanding of 21 CFR 314 requirements for therapeutic equivalence

✔Global SME in in-vitro dermatopharmacokinetics and IVRT / IVPT methodologies

✔Member of FDA–industry expert panels and scientific advisory boards

✔Contributor to FDA-published guidance documents on topical product evaluation

✔Frequent panelist at FDA workshops on IVPT study design and regulatory compliance

✔Expertise in TE demonstration, skin variability, receptor media, and membrane selection

✔Collaborated with Logan Instruments to enhance Franz cell performance

✔Contributed to improvements in membrane integrity, thermodynamics, and sampling precision

✔Led design optimization for reproducibility and system suitability in IVRT / IVPT platforms

✔Recognized among top 10 global scientists in IVRT and IVPT research

Quality Assurance Leadership

Head of Quality Assurance

Role: Senior Quality Assurance Specialist – GxP Compliance

Experience: 15+ years in QA oversight for topical and transdermal studies

Core QA Oversight & Compliance

✔Leads QA unit for all IVRT and IVPT study activities

✔Ensures compliance with 21 CFR Part 210 / 211 (GMP) and 21 CFR Part 58 (GLP)

✔Adheres to EMA GxP frameworks and ICH Q10 pharmaceutical quality system

✔Manages QA lifecycle from method validation audits to batch record review

✔Implements real-time data integrity checks and regulatory compliance assurance

✔Successfully handled multiple FDA PAIs and GLP audits

✔Experienced in sponsor-led audits and quality assessments

✔Maintains continuous state of audit readiness across QA systems

✔Oversees SOP development and implementation for IVRT / IVPT operations

✔Validates membrane integrity using TEWL and electrical impedance methods

✔Leads IQ / OQ / PQ qualification for Franz diffusion cells and HPLC / UPLC systems

✔Ensures ALCOA+ principles and 21 CFR Part 11 compliance for electronic systems

✔Conducts risk-based QA reviews to ensure scientific validity and client confidence

FEASIBILITIES EVALUATED AT HEALIOS:

IVRT / IVPT Experience

Sr. No	Test Article	Dosage Form	Route of Delivery	Study	Guidance	Submission
1	Glyceryl Trinitrate	Ointment	Rectal	IVRT	Yes	EU
2	Hydrocortisone Acetate	Cream	Rectal	IVRT	Yes	EU / GCC
3	Fusidic Acid	Cream	Topical	IVRT	Yes	EU
4	Sodium Fusidate	Ointment	Topical	IVRT	Yes	EU
5	Benzoyl Peroxide + Tretinoin	Cream	Topical	IVRT	Yes	EU
6	Clascoterone	Cream	Topical	IVRT / IVPT	Yes	USFDA / EU
7	Tacrolimus	Ointment	Topical	IVRT / IVPT	Yes	USFDA / NMPA
8	Rivastigmine	Transdermal Patch	Transdermal	Heat Flux IVPT	Yes	USFDA
9	Ruxolitinib	Cream	Topical	IVRT / IVPT	Yes	USFDA
10	Calcipotriene	Cream	Topical	IVPT	Yes	USFDA
11	Testosterone	Gel	Topical	IVRT / IVPT	No	USFDA / NMPA
12	Erythromycin	Ointment	Ophthalmic	IVRT	Yes	USFDA
13	Adapalene	Gel	Topical	IVPT	Yes	USFDA / NMPA
14	Diclofenac Diethylamine	Gel	Topical	IVRT / IVPT	Yes	TGA
15	Fusidic Acid	Cream	Topical	IVPT	No	NMPA
16	Ivermectin	Cream	Topical	IVPT	Yes	USFDA / NMPA