Transdermal Technology Research

Transdermal drug delivery system (TDDS) refers to the drug delivery route through the skin to local tissues or systemic blood circulation, resulting in local or systemic effects of the preparation. Transdermal preparations mainly include patch, ointment, gel, cream, foam, lotion and other dosage forms. As one of the new drug delivery technologies, transdermal technology is considered to be the focus of the fourth generation of preparations. BOC Sciences offers innovative approaches to transdermal technology.

Our transdermal drug delivery services

Innovative transdermal technology research

Chemical enhancers: Chemical enhancers are mainly used to improve the solubility of drugs in prescription and/or skin, change the thermodynamic properties of drugs, interact with the stratum corneum lipid bilayer, interact with the stratum corneum protein, or form ion pairs with drugs. Common hydrophilic penetration enhancers include carvone and menthol. Common lipophilic penetration enhancers are lemon essential oil; The amphiphilic penetration promotion mainly includes azone, pyrrolidone, terpenoids and fatty acids, among which azone, pyrrolidone and unsaturated fatty acids have relatively good effect on the penetration promotion of water-soluble drugs.

Iontophoresis: A physical osmotic method of transdermal drug delivery through the skin biofilm under the action of an applied electric field. The method increases the permeability of the skin, but does not destroy the skin barrier itself, so it is mainly suitable for small molecules carrying electric charges and some large molecules up to several thousand daltons. The biggest advantage of iontophoresis is that the speed at which the drug is delivered can vary with the current, which can be easily controlled by a microprocessor and, in some cases, by the patient.

Fig. 1 Schematic diagram illustrating the delivery mechanism of cationic drugs using iontophoresis. (Ramadon, D., 2021)

Ultrasonic penetration: The method of using ultrasonic wave to destroy the stratum corneum and form a temporary drug penetration channel to promote drug penetration (or absorption). The penetration promotion effect of low frequency ultrasound is better than that of high frequency ultrasound, and the mechanism of ultrasound penetration promotion may be related to the thermal effect, cavitation effect and flow effect. The thermal effect can make the tissue where the ultrasound acts obtain a lot of energy, thus speeding up the blood conduction and heat discharge rate.

Microneedles: Microneedles are needle-like micron-level fine structures processed by microelectromechanical technology, the length is generally 25 ~ 1 000 μm, and the materials are mostly silicon, metal, polymer and so on. According to the method of drug delivery, microneedles can be classified into solid microneedles, hollow microneedles, coated microneedles, soluble microneedles and phase conversion microneedles. The mechanism of the microneedle transdermal drug delivery system is that the drug enters the skin through the tiny pores formed after the microneedle penetrates the skin cuticle and enters the skin, so as to promote the effect of transdermal penetration and reach a specific depth of the skin.

Electroporation: The process of applying instantaneous high-voltage electric pulse electric field to lipid bilayer such as cell membrane to form temporary and reversible hydrophilic pores and increase the permeability of cell and tissue membrane. Electroporation is particularly suitable for transdermal delivery of biomacromolecules, and it has active applications in the delivery of proteins, oligonucleotides, small molecules, heparin, insulin, dextran and vitamin C.

Microemulsion: A transparent or translucent, low viscosity, isotropic and thermodynamically stable solution system formed spontaneously from aqueous, oil, surfactant and cosurfactant phases in appropriate proportions. The particle size of the microemulsion is uniform, generally between 10 and 100 nm, and the stability is good. It promotes the percutaneous permeability of drugs by increasing the solubility of drugs and the concentration gradient between the inner and outer layers of skin. Its own oil phase and surfactant also increase the fluidity of the stratum corneum lipid bilayer.

Liposome and nano-liposome: As a transdermal drug delivery carrier, liposome not only has low toxicity and irritation, but also has a slow-release effect on insoluble drugs and avoids drug degradation. As a new drug preparation transmitter, flexible nano-liposome has many characteristics, the biggest difference between it and liposome is that it has a high deformability. The driving force of transdermal absorption of the transmitter is osmotic pressure difference, which can cause significant deformability of the transmitter through accumulation of cholic acid molecules in the preparation during the process of penetrating the skin. Small and large molecules (peptides or proteins) can be successfully contained within the transmitter and successfully entered the systemic circulation according to the widening of the gap created by the surrounding cells.

Transdermal gel: It is a semi-solid or liquid preparation with certain viscosity prepared by mixing the drug with the appropriate gel matrix. It is uniform and delicate in texture, can form a film on the skin, has strong adhesion, long retention time, no irritation to the skin and mucosa, and can produce slow release or controlled release of the drug. Commonly used skin topical gel substrates are gelatin, chitosan, carbomer, Poloxamer, sodium carboxymethyl cellulose (CMC-Na), polyethylpyrrolidone (PVP), polyvinyl alcohol (PVA), hydroxypropyl methyl cellulose (HPMc) and so on.

At BOC Sciences, β-cyclodextrin, solid lipid nanoparticles (SLN), polymer micelles (PMs) and other substances can also be used as transdermal delivery carriers to promote the absorption of drugs.

Formulation development

• Transdermal patch
• Gels and creams
• Ointments
• Foams
• Lotions
• Microneedles

In vitro and in vivo testing

Quantitative drug analysis: High performance liquid chromatography (HPLC), mass spectrometry (MS), and other sophisticated techniques to measure drug concentration and purity.

Stability testing: assessment under various storage conditions to ensure the life and consistency of the preparation.

In vitro skin penetration studies: Use of human or animal skin in vitro to assess drug penetration and retention. Obtain reliable data using Franz diffusion cells and other penetration systems.

In vivo animal studies: Pharmacokinetic and pharmacodynamic studies are performed in relevant animal models to evaluate the systemic exposure and therapeutic effect of the formulation.

Advantages of our transdermal technology

Non-invasive and patient friendly: The transdermal system eliminates the need for needles, reducing pain and discomfort associated with injections. This improves patient compliance, especially for patients with chronic diseases that require long-term treatment.

Controlled drug release: Our formulations are designed to provide controlled and sustained drug release to maintain therapeutic levels over an extended period of time. This can reduce the frequency of administration and improve treatment outcomes.

Enhanced bioavailability: By bypassing the gastrointestinal tract and first-pass metabolism, transdermal delivery improves the bioavailability of the drug, ensuring a more effective therapeutic effect.

Reduce side effects: Transdermal systems provide local drug delivery, minimizing systemic exposure and reducing the risk of side effects.

Versatility: Can accommodate a variety of drugs, including small molecules, peptides and proteins. This versatility allows us to address a wide range of therapeutic needs in different disease areas.

Customized solutions: BOC Sciences provides customized solutions to meet your specific requirements. From the initial concept to the final product, our team works closely with our customers to ensure the successful development of transdermal systems.

FAQ

1. How does transdermal drug delivery work?

Transdermal drug delivery systems are designed to deliver drugs across the skin barrier (stratum corneum) into the bloodstream or target tissues. They use various mechanisms such as passive diffusion, chemical enhancers, or physical methods (e.g., microneedles) to enhance drug permeation.

2. What types of drugs can be delivered transdermally?

Transdermal delivery is suitable for a wide range of drugs, including small molecules, peptides, and proteins. It is particularly beneficial for drugs with poor oral bioavailability or those requiring controlled release.

3. What are the key components of your transdermal technology platform?

• Skin permeation enhancement: Using physical and chemical methods.
• Formulation development: Creating effective and patient-friendly formulations.
• Advanced drug carriers: Utilizing nanoparticles, liposomes, and ethosomes.
• In vitro and in vivo testing: Rigorous evaluation of formulations.
• Regulatory compliance: Ensuring quality and adherence to standards.

4. What advanced technologies and equipment do you use?

• High-performance liquid chromatography (HPLC)
• Differential scanning calorimetry (DSC)
• Fourier transform infrared spectroscopy (FTIR)
• Scanning electron microscopy (SEM)
• In vitro skin permeation systems
• Skin models and in vivo animal models

5. How do you ensure the safety and efficacy of transdermal formulations?

We conduct comprehensive in vitro and in vivo testing, including skin permeation studies and pharmacokinetic/pharmacodynamic evaluations. Rigorous quality control measures are implemented to ensure safety, efficacy, and stability.

6. Can you customize transdermal systems for specific client needs?

Yes, we provide tailored solutions to meet the specific requirements of our clients. From initial concept to final product, we work closely with clients to develop successful transdermal systems.

7. What are the challenges of transdermal drug delivery?

The primary challenge is the skin's barrier function, particularly the stratum corneum. Our advanced permeation enhancement techniques and innovative formulations address this challenge, ensuring efficient drug delivery.

8. How long can a transdermal patch be worn?

The duration varies depending on the drug and formulation. Some patches are designed for daily application, while others can last several days or even weeks, providing sustained drug release.

9. Are there any side effects of transdermal drug delivery systems?

Side effects are generally minimal compared to other routes of administration. However, some individuals may experience skin irritation or allergic reactions. Our formulations are designed to minimize these risks.

10. How do you select the appropriate formulation for a drug?

We consider various factors such as the drug's physicochemical properties, therapeutic requirements, and patient preferences. Our formulation scientists optimize the drug release profile, stability, and patient acceptability.