Iontophoresis-coupled rapidly dissolving polymeric microneedle patch of naloxone for its enhanced transdermal delivery

The transdermal delivery of naloxone for opioid overdose emergency purposes is a challenge due to its poor rate of diffusion through the layers of skin. This results in delayed delivery of an insufficient amount of the drug within minimal time as is desired to save lives. The ability of dissolving polymeric microneedles to shorten the lag time significantly has been explored and shown to have prospects in terms of the transdermal delivery of naloxone. This is an option that offers critical advantages to the ongoing opioid crisis, including ease of distribution and easy administration, with little to no need for intervention by clinicians. Nonetheless, this approach by itself needs augmentation to meet pharmacokinetic delivery attributes desired for a viable clinical alternative to existing market dosage forms. In this study, we report the success of an optimized iontophoresis-coupled naloxone loaded dissolving microneedle patch which had facilitated a 12- fold increase in average cumulative permeation and a 6-fold increase in drug flux over a conventional dissolving microneedle patch within 60 min of application (p < 0.05). This translates to a 30 % decrease in dose requirement in a mechanistically predicted microneedle patch established to be able to achieve the desired early plasma concentration time profile needed in an opioid overdose emergency. Applying a predictive mathematical model, we describe an iontophoresis-coupled microneedle patch design capable of meeting the desired pharmacokinetic profile for a viable naloxone delivery form through skin.

Tofacitinib in dermatology: a potential opportunity for topical applicability through novel drug-delivery systems

Tofacitinib is a first-generation JAK inhibitor approved by the US FDA for treating rheumatoid arthritis. It exhibits a broad-spectrum inhibitory effect with abilities to block JAK-STAT signalling. The primary objective of this review is to obtain knowledge about cutting-edge methods for effectively treating a variety of skin problems by including tofacitinib into formulations that are based on nanocarriers. The review also highlights clinical trials and offers an update on published clinical patents. Nanocarriers provide superior performance compared to conventional treatments in terms of efficacy, stability, drug bioavailability, target selectivity and sustained drug release. Current review has the potential to make significant contributions to the ongoing discussion involving dermatological treatments and the prospective impact of nanotechnology on transforming healthcare within this field.

Microneedle Mediated Iontophoretic Delivery of Tofacitinib Citrate

PURPOSE

To investigate in vitro transdermal delivery of tofacitinib citrate across human skin using microporation by microneedles and iontophoresis alone and in combination.

METHODS

In vitro permeation studies were conducted using vertical Franz diffusion cells. Microneedles composed of polyvinyl alcohol and carboxymethyl cellulose were fabricated and successfully characterized using scanning electron microscopy. The microchannels created were further characterized using histology, dye binding study, scanning electron microscopy, and confocal microscopy studies. The effect of microporation on delivery of tofacitinib citrate was evaluated alone and in combination with iontophoresis. In addition, the effect of current density on iontophoretic delivery was also investigated.

RESULTS

Total delivery of tofacitinib citrate via passive permeation was found out to be 11.04 ± 1 μg/sq.cm. Microporation with microneedles resulted in significant enhancement where a 28-fold increase in delivery of tofacitinib citrate was observed with a total delivery of 314.7±33.32 μg/sq.cm. The characterization studies confirmed the formation of microchannels in the skin where successful disruption of stratum corneum was observed after applying microneedles. Anodal iontophoresis at 0.1 and 0.5 mA/sq.cm showed a total delivery of 18.56 μg/sq.cm and 62.07 μg/sq.cm, respectively. A combination of microneedle and iontophoresis at 0.5 mA/sq.cm showed the highest total delivery of 566.59 μg/sq.cm demonstrating a synergistic effect. A sharp increase in transdermal flux was observed for a combination of microneedles and iontophoresis.

CONCLUSION

This study demonstrates the use of microneedles and iontophoresis to deliver a therapeutic dose of tofacitinib citrate via transdermal route.

Lateral Dermal Penetration is Dependent on the Lipophilicity of Active Ingredients

INTRODUCTION

With its large surface area skin facilitates a topical administration of active ingredients, and thus percutaneous delivery to a specific target site. Due to its high barrier function and different diffusion characteristics skin governs the efficacy of these active ingredients and a bioavailability in the epidermal and dermal tissue.

OBJECTIVE

In order to characterize the vertical and lateral movement of molecules into and inside the skin the diffusivity of active ingredients with different physico-chemical properties and their penetration ability in different dermal skin layers was investigated.

METHODS

A novel lateral dermal microdialysis (MD) penetration setup was used to compare the diffusion characteristics of active ingredients into superficial and deep implanted MD membranes in porcine skin. The corresponding membrane depth was determined via ultrasound and the active ingredients concentration via high-pressure liquid chromatography (HPLC) measurement.

RESULTS

The depth depended penetration of superficial and deep implanted MD membranes and the quantitative diffusivity of two active ingredients was compared. An experimental lateral MD setup was used to determine the influence of percutaneous skin penetration characteristics of an active ingredient with different lipophilic and hydrophilic characteristics. Therefore, hydrophilic caffeine and lipophilic LIP1, which have an identical molecular weight, but different lipophilic characteristics were tested for their penetration ability inside a propylene glycol (PG) and oleic acid (OA) formulation.

CONCLUSION

The vertical and lateral penetration movement of caffeine was found to exceed that of LIP1 through the hydrophilic dermal environment. The findings of this study show that the lipophilicity of active ingredients influence the penetration movement and that skin enables a conical increasing lateral diffusivity and transdermal delivery.

Transdermal Delivery Systems for Biomolecules

Purpose

The present review article focuses on highlighting the main technologies used as tools that improve the delivery of transdermal biomolecules, addressing them from the point of view of research in the development of transdermal systems that use physical and chemical permeation enhancers and nanocarrier systems or a combination of them.

Results

Transdermal drug delivery systems have increased in importance since the late 1970s when their use was approved by the Food and Drug Administration (FDA). They appeared to be an alternative resource for the administration of many potent drugs. The first transdermal drug delivery system used for biomolecules was for the treatment of hormonal disorders. Biomolecules have been used primarily in many treatments for cancer and diabetes, vaccines, hormonal disorders, and contraception.

Conclusions

The latest technologies that have used such transdermal biomolecule transporters include electrical methods (physical penetration enhancers), some chemical penetration enhancers and nanocarriers. All of them allow the maintenance of the physical and chemical properties of the main proteins and peptides through these clinical treatments, allowing their efficient storage, transport, and release and ensuring the achievement of their target and better results in the treatment of many diseases.

Graphical abstract

Characterization of microneedles and microchannels for enhanced transdermal drug delivery

Microneedle (MN)-based technologies are currently one of the most innovative approaches that are being extensively investigated for transdermal delivery of low molecular weight drugs, biotherapeutic agents and vaccines. Extensive research reports, describing the fabrication and applications of different types of MNs, can be readily found in the literature. Effective characterization tools to evaluate the quality and performance of the MNs as well as for determination of the dimensional and kinetic properties of the microchannels created in the skin, are an essential and critical part of MN-based research. This review paper provides a comprehensive account of all such tools and techniques.