# The effects of pharmacologic and physiologic variables on the pharmacokinetics of microneedle drug delivery

> **NIH NIH R35** · UNIVERSITY OF IOWA · 2021 · $375,099

## Abstract

PROJECT SUMMARY/ABSTRACT
Microneedles are a minimally invasive method for enhancing skin permeability through the creation of
micropores in the epidermis. The micropores are aqueous pathways that allow an otherwise skin-impermeable
drug to pass through the skin and be delivered systemically. This has important implications for the treatment
of many diseases in diverse patient populations. Drug delivery parameters (drug formulation, microneedle
length/number) and in vivo considerations (rate of closure of the micropores) both contribute to the
pharmacokinetics and drug disposition. Despite extensive study of microneedles in humans, there is a large
paucity of data describing how physiologic factors such as sex/gender and race/ethnicity affect the drug
delivery profile. Many significant differences are present in the skin of subjects of differing sex/gender and
race/ethnicity, including variations in epidermal thickness, reactivity, and recovery from insult. Epidermal
thickness also varies dramatically between different sites of the body. In order to achieve widespread use of
microneedles for drug delivery, it is necessary to understand the variability in drug delivery profiles between
diverse patient subgroups. The effect of physiologic factors on the drug delivery profile cannot be predicted
from in vitro diffusion studies, which makes it critical to study the in vitro and in vivo settings together. The long-
term goal of this research is to develop advanced microneedle delivery platforms that will improve
pharmacotherapy and treatment for diverse patient populations with a variety of acute and chronic diseases.
The strategy of this 5 year MIRA research program is to make correlations between preclinical drug delivery
studies and clinical human microneedle studies by combining fundamental and applied research. In vitro
studies will aim to maximize percutaneous flux of macromolecules and small molecules by optimizing
formulation and microneedle delivery parameters. We will study micropore closure rates and drug absorption
profiles from numerous anatomical sites in healthy human volunteers of differing sex/gender and race/ethnicity.
Microneedle length and number, and drug formulation will be studied as additional factors that may contribute
to in vivo variability. In the clinical studies we will calculate micropore closure half-lives under various
conditions and validate the predictions with pharmacokinetic studies. Correlations will be made between in vitro
percutaneous flux studies and in vivo pharmacokinetic studies for each patient population. This MIRA program
will expand our understanding of how physiologic variables affect microneedle drug delivery in healthy
subjects, and in the future we will expand upon these results and perform micropore closure and
pharmacokinetic studies in patients with systemic diseases. This will enable us to understand how diseases
further contribute to variation in response to microneedles. We then will have the n...

## Key facts

- **NIH application ID:** 10241929
- **Project number:** 5R35GM124551-05
- **Recipient organization:** UNIVERSITY OF IOWA
- **Principal Investigator:** Nicole K Brogden
- **Activity code:** R35 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $375,099
- **Award type:** 5
- **Project period:** 2017-09-01 → 2023-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10241929

## Citation

> US National Institutes of Health, RePORTER application 10241929, The effects of pharmacologic and physiologic variables on the pharmacokinetics of microneedle drug delivery (5R35GM124551-05). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10241929. Licensed CC0.

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