Transdermal drug delivery is a method of administering medications through the skin for systemic distribution. Unlike topical delivery, which targets the local area where the medication is applied, transdermal delivery ensures that the drug enters the bloodstream and circulates throughout the body. This route is commonly used for patches or ointments that release the drug over time, providing a controlled and sustained therapeutic effect

The process involves the drug passing through the skin’s layers, including the stratum corneum, epidermis, and dermis, to reach the systemic circulation. Transdermal delivery is advantageous because it bypasses the gastrointestinal tract, avoiding first-pass metabolism, and can offer a more consistent drug level in the blood compared to oral administration.  It’s particularly useful for chronic conditions requiring long-term medication, such as pain management, hormonal therapy, and cardiovascular diseases.

The stratum corneum is the primary barrier to transdermal drug delivery, and overcoming this requires innovative technologies and formulation strategies. 

We cover the full spectrum of product development, from initial research and formulation to full-scale commercial production.


Medicine in a Jar

Transdermal Drug Delivery

Transdermal drug delivery refers to the application of drugs onto the skin with the intention of delivering the drug into the bloodstream for systemic distribution. 

  • Systemic Effect: Transdermal drugs are designed to penetrate through the skin layer and exert their effects on deeper or more distant tissues. They are used to treat conditions that affect the whole body, such as chronic pain or hormone imbalances.


  • Controlled Release: Transdermal drug delivery systems can provide controlled and sustained release of drugs, which can improve patient compliance and therapeutic outcomes.


  • Avoidance of First-Pass Metabolism: Transdermal drug delivery bypasses the gastrointestinal tract and liver, avoiding first-pass metabolism. This can increase the bioavailability of the drug and reduce side effects.


Transdermal Dosage Forms

  • Transdermal Patches: These are medicated adhesive patches designed to release a specific dose of medication through the skin and into the bloodstream over a set period. They offer the advantage of maintaining steady drug levels in the blood, reducing dosing frequency, and improving patient compliance. Examples include nicotine patches for smoking cessation and fentanyl patches for pain management.

  • Transdermal Gels: These are semi-solid systems that facilitate the absorption of active ingredients through the skin. They are often preferred for their ease of application and ability to deliver a range of drugs, including hormones like testosterone or estradiol.


  • Transdermal Sprays: These are liquid formulations that are sprayed onto the skin. The medication is absorbed through the skin and enters the systemic circulation. They provide a convenient and controlled dosing method, often used for drugs that require rapid onset of action.


  • Transdermal Films: Thin films that adhere to the skin and release medication over time. They are discreet and can be designed to provide both local and systemic effects.


  • Transdermal Foams: These are formulations that produce a foam when dispensed. The foam collapses upon application to the skin, allowing for the drug to be absorbed. This dosage form can be particularly useful for topical steroids or other anti-inflammatory agents.


  • Transdermal Emulsions (Lotions): These are oil-in-water or water-in-oil emulsions that can be spread on the skin for drug delivery. They combine the advantages of creams and ointments but are more easily spreadable and can cover larger surface areas.


  • Transdermal Aerosols: These are pressurized dosage forms that release a fine mist of medication that is applied to the skin. The active ingredient is absorbed through the skin and enters the bloodstream.


  • Transdermal Powders: Finely milled powders containing medication that can be dusted onto the skin for absorption. While not as common, they can be used for drugs that are stable in powder form and can be absorbed through the skin.

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Here are some frequently asked questions about Topical / Transdermal.

What range of CDMO services does Renejix offer for topical/transdermal drug development?

Renejix provides a full spectrum of services for topical and transdermal drug development, from preformulation to clinical formulations. This includes expertise in small molecule oral dosage development, delivery technologies, and multi-modality manufacturing for both orphan drugs and generics.

How does Renejix handle complex APIs for topical/transdermal formulations?

Renejix boasts unrivaled expertise in formulating complex dosage forms. They employ various techniques to enhance bioavailability or achieve controlled release, even for the most challenging APIs, across dosage forms like creams, emulsions, liquids, and films.

What quality assurance measures does Renejix implement for topical/transdermal products?

Renejix ensures compliance with stringent industry standards, guaranteeing product integrity and timely market entry. Their quality assurance processes are designed to meet or exceed the highest quality benchmarks, reducing risk and ensuring regulatory compliance.

Can Renejix support both small-scale and large-scale formulation development?

Yes, Renejix’s capabilities encompass comprehensive services for small, pilot, full-scale, and adaptive manufacturing solutions across all phases of clinical trials. They are equipped to handle challenges from preclinical to commercial stages.

What specialized technologies does Renejix use for drug penetration/permeation enhancement?

Renejix utilizes specialized technologies to increase drug efficacy, bioavailability, and adherence. They offer a variety of dosage forms and have a track record of developing new formulation approaches and optimizing existing products.

Does Renejix provide regulatory services to ensure global compliance?

Absolutely. Renejix offers strategic regulatory planning and quality assurance to ensure global compliance, streamline approvals, and support the product lifecycle.

What analytical and testing services are available at Renejix?

Renejix has over 200+ analytical scientists providing comprehensive analytical testing and method development for quality, validation, and compliance. They support Q1/Q2 evaluations and develop in vitro release testing protocols.

How does Renejix approach preclinical development?

Renejix’s integrated approach ensures the right form and formulation from the start, employing a First-Time Right Approach for streamlined development. They screen drug candidates for viability and ensure the safety of clinical trial participants.

What makes Renejix a trusted partner in the CDMO industry?

Renejix is recognized for its faster time-to-market, cutting up to 20 weeks off early and late phase timelines. Their seasoned management team brings 30+ years of industry knowledge on average, ensuring programs are guided by proven professionals.