Background/Objectives: Laurocapram (Azone) attracted attention 40 years ago as a compound with the highest skin-penetration-enhancing effect at that time; however, its development was shelved due to strong skin irritation. We had already prepared and tested an ante-enhancer (IL-Azone), an ionic liquid (IL) with a similar structure to Azone, consisting of ε-caprolactam and myristic acid, as an enhancer candidate that maintains the high skin-penetration-enhancing effect of Azone with low skin irritation. In the present study, fatty acids with different carbon numbers (caprylic acid: C8, capric acid: C10, lauric acid: C12, myristic acid: C14, and oleic acid: C18:1) were selected and used with ε-caprolactam to prepare various IL-Azones in the search for a more effective IL-Azone. Methods: Excised porcine skin was pretreated with each IL-Azone to assess the in vitro skin permeability of antipyrine (ANP) as a model penetrant. In addition, 1,3-butanediol was selected for the skin permeation test to confirm whether the effect of IL-Azone was due to fatty acids and if this effect differed depending on the concentration of IL-Azone applied. Results: The results obtained showed that C12 IL-Azone exerted the highest skin-penetration-enhancing effect, which was higher than Azone. On the other hand, many of the IL-Azones tested had a lower skin-penetration-enhancing effect. Conclusions: These results suggest the potential of C12 IL-Azone as a strong and useful penetration enhancer.

Allergic contact dermatitis (ACD) can easily develop once sensitization is established by exposure to small amounts of antigen, and steroids are used for treatment. In this study, we evaluated the therapeutic efficacy of prednisolone (PSL)-loaded poly(DL-lactide-co-glycolide) (PLGA) nanoparticles (NPs) on a mouse model of contact dermatitis (CHS). Nanoparticles were prepared using a poor solvent diffusion method, and particle size distribution and mean particle size were measured using dynamic light scattering. Treatment experiments with PSL-loaded PLGA NPs were performed before and after sensitization with 1-fluoro-2,4-dinitrobenzene (DNFB), and evaluation was performed by quantifying intracutaneous IL-4 and TNF-α levels in a mouse model of CHS using ELISA. When PSL-loaded PLGA NPs were administered before sensitization, IL-4 expression was significantly decreased, and TNF-α tended to decrease in the group treated with PSL-loaded PLGA NPs compared to the non-treated group. When PSL-loaded PLGA NPs were administered after sensitization, IL-4 expression was significantly decreased in the group treated with PSL-loaded PLGA NPs compared to the non-treated group. In both cases, there were no significant differences between the PSL-loaded PLGA NP treatment group and the PSL-containing ointment group. These results suggest that, in the treatment of CHS, PSL-loaded PLGA NPs show a certain therapeutic effect when preadministration.

The wearing of medical gowns during anticancer drug preparation is recommended for the prevention of drug exposure. Non-breathable and breathable gowns (gown− and gown+, respectively) are both available. However, anticancer drugs may permeate “gown+.” In the present study, water, hydrophilic and lipophilic dyes, and aqueous solutions of several model chemicals with different physical properties (pyridoxine, antipyrine, ethyl p-hydroxybenzoate, and butyl p-hydroxybenzoate) were applied to four types of gowns and their chemical permeabilities were measured. The permeability of gowns to vaporized ethanol was also investigated because several volatile anticancer drugs are currently used in the treatment of cancer. The results obtained showed that the hydrophilic chemical, pyridoxine, did not permeate any of the gowns tested. Furthermore, gowns became more permeable as the lipophilicity of chemicals increased. No significant changes were observed in the chemical permeability between “gown−” and “gown+,” suggesting that the protective efficacy of the gowns against permeation by anticancer drugs was similar regardless of breathability. On the contrary, “gown + ” was permeable to vaporized ethanol, whereas “gown−” was not. The present study demonstrates the need for safety measures in lipophilic or volatile anticancer drug handling and the importance of developing medical gowns that are highly resistant to chemical permeation.

Objective: Abraxane ^® intravenous infusion (albumin-bound paclitaxel nanoparticles; Abraxane ^® or paclitaxel nanoparticles) is a lyophilized cake formulation containing paclitaxel and human serum albumin in nanoparticulate form. Before use, it must be uniformly dispersed in saline. However, this reconstitution process often leads to foaming, necessitating careful handling and prolonging preparation time. This study aimed to investigate shaking conditions for rapid, uniform paclitaxel nanoparticle dispersion while minimizing foam formation. Additionally, we evaluated whether shaking affects nanoparticle size. Methods: After adding 20 mL of saline to a vial containing 100 mg of lyophilized cake, the vial was placed either vertically or horizontally on a shaker. Two shaking types were examined: linear reciprocal and orbital shaking. We varied shaking intensity and recorded the dispersion time and foam formation. Particle size was analyzed under the following three conditions: (1) control, (2) minimal dispersion time without foaming, and (3) the condition causing the most severe foaming. Results: When the vial was placed horizontally and subjected to orbital shaking at 100 rpm, uniform dispersion was achieved within 6.25 min without foaming. This was approximately one-third the time required under control conditions. Further, when particle size was measured under different shaking intensities in the horizontal setup, no significant change in nanoparticle size was observed regardless of shaking strength or time after preparation. Conclusion: In the reconstitution of Abraxane ^® , the optimal shaking condition identified in this study was demonstrated to not only preserve nanoparticle integrity but also reduce the time and effort required for healthcare professionals.