Your Dermatology Specialists
Choose QPS for Dermatology
Dermal and transdermal research is near and dear to our hearts at QPS, with our own Dermal Center of Excellence in North Dakota and a Clinical site in Missouri with extensive experience in conducting a wide range of Dermatology studies.
Leveraging our large volunteer database, former study subject database and in house marketing agency to target large, actively interested clinical trial populations ensures that QPS is consistently a top enroller. We use a central IRB to ensure full regulatory compliance. Our full time quality assurance team, regulatory department, rigorous standard operating procedures and experienced staff of study coordinators consistently provide quality results.
The Franz Diffusion Cell
The Franz Diffusion Cell is the industry standard for in vitro percutaneous absorption kinetics of topical and transdermal products using ex vivo human skin. This model and associated methodologies support drug development in the preclinical, clinical, and post-approval phases, including the in vitro rate-of-release assay (IVRT) based on the FDA SUPAC-SS Guidance.
Dermal and Transdermal Drug Delivery Systems (DTDDS) Introduction
Whereas dermatologic topical formulations (foams, creams, lotions, ointments, gels, etc.) target skin diseases, topical transdermal delivery systems (TDDS) are designed to treat systemic medical conditions or localized joint or muscle conditions, using the skin as the route of drug delivery. Transdermal drug delivery offers important advantages over other routes of administration. It is particularly useful for circumventing liver first-pass metabolism, as an alternative to oral products, for non-invasive localized muscle and joint treatments, to improve and simplify patient compliance, and to allow for discontinuation of drug delivery by removing the patch in the event of adverse drug reactions. TDDS have become successful alternatives for delivering medications to young children, the elderly and the infirm.
Dermal and Transdermal Drug Delivery Systems (DTDDS) Overview
Although transdermal systems are classified variously, transdermal patches can be divided into three main categories according to how the drug is incorporated into the delivery system.
An adhesive matrix patch is a system in which the adhesive layer contains the drug. In this type of patch, the adhesive layer not only serves to fix the TDDS to the skin but is also responsible for the controlled release of the drug.
A reservoir patch is a system with a liquid compartment containing a drug solution or suspension, enclosed by an adhesive layer and a semi-permeable membrane to control release.
A matrix patch is a system which includes a semisolid matrix containing a drug solution or suspension, independent of the adhesive.
Non-patch topical transdermal systems have also become popular. They are typically gels and creams, such as those designed to deliver testosterone, progesterone, and diclofenac sodium.
Transcutaneous Technologies and Devices
Apart from traditional transdermal patch products and topical semi-solids, extensive work is ongoing to develop transcutaneous technologies and devices, most of which are intended to disrupt or bypass the stratum corneum, the rate-limiting absorption barrier of the skin. Such techniques currently in development include microporation, laser ablation, radiofrequency (iontophoresis, sonophoresis, electroporation), thermal technologies (drug delivery augmented with heat), and microneedle systems. These diverse developing technologies are being investigated for use with a wide variety of difficult-to-deliver drug compounds and macromolecules (e.g. parathyroid hormone, insulin, vaccines, and biologics), and for drugs requiring rapid delivery (e.g. lidocaine, fentanyl and diclofenac).
Several of these systems are already available OTC, including microneedle rollers and iontophoresis and sonophoresis systems, which are predominately being used for cosmetic and anti-aging treatments and as therapy for localized sports injuries.