Porous microneedle arrays as promising tools for the quantification of drugs in the skin: a proof of concept study.

This study aimed to demonstrate the potential of using porous microneedles (PMNs) as a promising tool for the noninvasive quantification of topically applied pharmaceutical products. We fabricated a porous microneedle (PMN) from a blend of cellulose acetate and dimethyl sulfoxide by casting and phase separation; it was characterized using scanning electron microscopy, Raman spectroscopy, differential scanning calorimetry, and a Texture Analyzer. An ex vivo study was conducted as a proof-of-concept study to assess whether this PMN could be used to quantify drug absorption through the skin after the topical administration of two nonequivalent products of sodium ibuprofen (gel and dissolving microneedles). Three cellulose acetate formulations (PMN1: 37.5%, PMN-2: 44.4%, and PMN-3: 50%) were used to prepare PMN patches; subsequently, these were evaluated for their morphological and insertion properties. Only PMN-2 microneedle patches were chosen to continue with the ex vivo study. The ex vivo study results demonstrated that PMNs could absorb and release sodium ibuprofen (SDIB) and differentiate between two different SDIB topical products. This can be attributed to the porous and interconnected architecture of these microneedles. This developmental study highlights the potential success of such a tool for the quantification of dermal drug concentration and supports moving to in vivo tests.

Amphotericin B- and Levofloxacin-Loaded Chitosan Films for Potential Use in Antimicrobial Wound Dressings: Analytical Method Development and Its Application.

Levofloxacin (LVX) and amphotericin B (AMB) have been widely used to treat bacterial and fungal infections in the clinic. Herein, we report, for the first time, chitosan films loaded with AMB and LVX as wound dressings to combat antimicrobial infections. Additionally, we developed and validated a high-performance liquid chromatography (HPLC) method coupled with a UV detector to simultaneously quantify both AMB and LVX. The method is easy, precise, accurate and linear for both drugs at a concentration range of 0.7-5 µg/mL. The validated method was used to analyse the drug release, ex vivo deposition and permeation from the chitosan films. LVX was released completely from the chitosan film after a week, while approximately 60% of the AMB was released. Ex vivo deposition study revealed that, after 24-hour application, 20.96 ± 13.54 µg of LVX and approximately 0.35 ± 0.04 µg of AMB was deposited in porcine skin. Approximately 0.58 ± 0.16 µg of LVX permeated through the skin. AMB was undetectable in the receptor compartment due to its poor solubility and permeability. Furthermore, chitosan films loaded with AMB and LVX were found to be able to inhibit the growth of both Candida albicans and Staphylococcus aureus, indicating their potential for antimicrobial applications.