Improvement of lidocaine skin permeation by using passive and active enhancer methods.

Lidocaine is generally recognized and preferred for local anaesthesia, but in addition, studies have described additional benefits of lidocaine in cancer therapy, inflammation reduction, and wound healing. These properties contribute to its increasing importance in dermatological applications, and not only in pain relief but also in other potential therapeutic outcomes. Therefore, the purpose of our study was to enhance lidocaine delivery through the skin. A stable nanostructured lipid carrier (NLC), as a passive permeation enhancer, was developed using a 23 full factorial design. The nanosystems were characterized by crystallinity behaviour, particle size, zeta potential, encapsulation efficiency measurements, and one of them was selected for further investigation. Then, NLC gel was formulated for dermal application and compared to a traditional dermal ointment in terms of physicochemical (rheological behaviour) and biopharmaceutical (qualitative Franz diffusion and quantitative Raman investigations) properties. The study also examined the use of 3D printed solid microneedles as active permeation enhancers for these systems, offering a minimally invasive approach to enhance transdermal drug delivery. By actively facilitating drug permeation through the skin, microneedles can complement the passive transport achieved by NLCs, thereby providing an innovative and synergistic approach to improving lidocaine delivery.

Design, Optimization, and Application of a 3D-Printed Polymer Sample Introduction System for the ICP-MS Analysis of Nanoparticles and Cells.

Commonly used sample introduction systems for inductively coupled plasma mass spectrometry (ICP-MS) are generally not well-suited for single particle ICP-MS (spICP-MS) applications due to their high sample requirements and low efficiency. In this study, the first completely 3D-printed, polymer SIS was developed to facilitate spICP-MS analysis. The system is based on a microconcentric pneumatic nebulizer and a single-pass spray chamber with an additional sheath gas flow to further facilitate the transport of larger droplets or particles. The geometry of the system was optimized using numerical simulations. Its aerosol characteristics and operational conditions were studied via optical particle counting and a course of spICP-MS measurements, involving nanodispersions and cell suspensions. In a comparison of the performance of the new and the standard (quartz microconcentric nebulizer plus a double-pass spray chamber) systems, it was found that the new sample introduction system has four times higher particle detection efficiency, significantly better signal-to-noise ratio, provides ca. 20% lower size detection limit, and allows an extension of the upper limit of transportable particle diameters to about 25 µm.

Pharmaceutical Development and Design of Thermosensitive Liposomes Based on the QbD Approach.

This study aimed to produce thermosensitive liposomes (TSL) by applying the quality by design (QbD) concept. In this paper, our research group collected and studied the parameters that significantly impact the quality of the liposomal product. Thermosensitive liposomes are vesicles used as drug delivery systems that release the active pharmaceutical ingredient in a targeted way at ~40-42 °C, i.e., in local hyperthermia. This study aimed to manufacture thermosensitive liposomes with a diameter of approximately 100 nm. The first TSLs were made from DPPC (1,2-dipalmitoyl-sn-glycerol-3-phosphocholine) and DSPC (1,2-dioctadecanoyl-sn-glycero-3-phosphocholine) phospholipids. Studies showed that the application of different types and ratios of lipids influences the thermal properties of liposomes. In this research, we made thermosensitive liposomes using a PEGylated lipid besides the previously mentioned phospholipids with the thin-film hydration method.