Mechanistic Study of Release Characteristics of Two Active Ingredients in Transdermal Patch Containing Lidocaine-Flurbiprofen Ionic Liquid

The molecular design of novel phospholipid-inspired ionic liquid transdermal penetration enhancers: Innovative insights on the action mode and mechanism

Ionic liquid transdermal penetration enhancers (IL@TPEs) as new enhancement methods have significant advantages in the transdermal drug delivery system. However, the scientific frameworks for the design of efficient IL@TPEs and their applications in transdermal formulations were still lack. So, a series of novel biomimetic phospholipid-inspired IL@TPEs (PIL@TPEs) were designed and synthesized. The developed QSARs proved that enhancement efficacy of PIL@TPEs depended on pKa of drugs and M.W., Polar., and pKa of cations. Surprisingly, the PIL@TPEs dissociated during transdermal process, and skin penetration amounts of acidic drugs was inversely proportional to skin retention amounts of cations, which showed that action modes of PIL@TPEs were different from conventional enhancers. The novel mechanisms of PIL@TPEs were elucidated by quantitative determination of dynamic interaction among cations, anions, drugs, and skins. The PIL@TPEs with high enhancement efficiency owned strong interactions with drugs determined by ATR-FTIR, Raman and NOESY. Moreover, the PIL@TPEs owning better stability in skin ensured the production of strong interactions with lipids and keratins characterized by ATR-FTIR, 1H NMR and CLSM. The good safety of optimized PIL@TPEs was proved by determining cytotoxicity, apoptosis, inflammatory cells, and cytokines. In conclusion, this project will make an important contribution to the design and application of IL@TPEs.

Ionic liquids as the effective technology for enhancing transdermal drug delivery: Design principles, roles, mechanisms, and future challenges

Ionic liquids (ILs) have been proven to be an effective technology for enhancing drug transdermal absorption. However, due to the unique structural components of ILs, the design of efficient ILs and elucidation of action mechanisms remain to be explored. In this review, basic design principles of ideal ILs for transdermal drug delivery system (TDDS) are discussed considering melting point, skin permeability, and toxicity, which depend on the molar ratios, types, functional groups of ions and inter-ionic interactions. Secondly, the contributions of ILs to the development of TDDS through different roles are described: as novel skin penetration enhancers for enhancing transdermal absorption of drugs; as novel solvents for improving the solubility of drugs in carriers; as novel active pharmaceutical ingredients (API-ILs) for regulating skin permeability, solubility, release, and pharmacokinetic behaviors of drugs; and as novel polymers for the development of smart medical materials. Moreover, diverse action mechanisms, mainly including the interactions among ILs, drugs, polymers, and skin components, are summarized. Finally, future challenges related to ILs are discussed, including underlying quantitative structure-activity relationships, complex interaction forces between anions, drugs, polymers and skin microenvironment, long-term stability, and in vivo safety issues. In summary, this article will promote the development of TDDS based on ILs.

Strategies for Improving Transdermal Administration: New Approaches to Controlled Drug Release

In this work, we aim to address several strategies to improve transdermal drug delivery, such as iontophoresis, sonophoresis, electroporation and micron. We also propose a review of some transdermal patches and their applications in medicine. TDDs (transdermal patches with delayed active substances) are multilayered pharmaceutical preparations that may contain one or more active substances, of which, systemic absorption is achieved through intact skin. The paper also presents new approaches to the controlled release of drugs: niosomes, microemulsions, transfersomes, ethosomes, but also hybrid approaches nanoemulsions and microns. The novelty of this review lies in the presentation of strategies to improve the transdermal administration of drugs, combined with their applications in medicine, in light of pharmaceutical technological developments.