Comparative study on the topical and transdermal delivery of diclofenac incorporated in nano-emulsions, nano-emulgels, and a colloidal suspension

Bcl-2 knockdown by multifunctional lipid nanoparticle and its influence in apoptosis pathway regarding cutaneous melanoma: in vitro and ex vivo studies

Multifunctional therapies have emerged as innovative strategies in cancer treatment. In this research article, we proposed a nanostructured lipid carrier (NLC) designed for the topical treatment of cutaneous melanoma, which simultaneously delivers 5-FU and Bcl-2 siRNA. The characterized nanoparticles exhibited a diameter of 259 ± 9 nm and a polydispersion index of 0.2, indicating a uniform size distribution. The NLCs were primarily localized in the epidermis, effectively minimizing the systemic release of 5-FU across skin layers. The ex vivo skin model revealed the formation of a protective lipid film, decreasing the desquamation process of the stratum corneum which can be associated to an effect of increasing permeation. In vitro assays demonstrated that A375 melanoma cells exhibited a higher sensitivity to the treatment compared to non-cancerous cells, reflecting the expected difference in their metabolic rates. The uptake of NLC by A375 cells reached approximately 90% within 4 h. The efficacy of Bcl-2 knockdown was thoroughly assessed using ELISA, Western blot, and qRT-PCR analyses, revealing a significant knockdown and synergistic action of the NLC formulation containing 5-FU and Bcl-2 siRNA (at low concentration --100 pM). Notably, the silencing of Bcl-2 mRNA also impacted other members of the Bcl-2 protein family, including Mcl-1, Bcl-xl, BAX, and BAK. The observed modulation of these proteins strongly indicated the activation of the apoptosis pathway, suggesting a successful inhibition of melanoma growth and prevention of its in vitro spread.

Formulation and Ex Vivo Evaluation of Ivermectin Within Different Nano-Drug Delivery Vehicles for Transdermal Drug Delivery

Background/Objectives: Ivermectin gained widespread attention as the "miracle drug" during the coronavirus disease 2019 (COVID-19) pandemic. Its inclusion in the 21st World Health Organization (WHO) List of Essential Medicines is attributed to its targeted anti-helminthic response, high efficacy, cost-effectiveness and favorable safety profile. Since the late 2000s, this bio-inspired active pharmaceutical ingredient (API) gained renewed interest for its diverse therapeutic capabilities. However, producing ivermectin formulations does remain challenging due to its poor water solubility, resulting in low bioavailability after oral administration. Therefore, the transdermal drug delivery of ivermectin was considered to overcome these challenges, which are observed after oral administration. Methods: Ivermectin was incorporated in a nano-emulsion, nano-emulgel and a colloidal suspension as ivermectin-loaded nanoparticles. The nano-drug delivery vehicles were optimized, characterized and evaluated through in vitro membrane release studies, ex vivo skin diffusion studies and tape-stripping to determine whether ivermectin was successfully released from its vehicle and delivered transdermally and/or topically throughout the skin. This study concluded with cytotoxicity tests using the methyl thiazolyl tetrazolium (MTT) and neutral red (NR) assays on both human immortalized epidermal keratinocytes (HaCaT) and human immortalized dermal fibroblasts (BJ-5ta). Results: Ivermectin was successfully released from each vehicle, delivered transdermally and topically throughout the skin and demonstrated little to no cytotoxicity at concentrations that diffused through the skin. Conclusions: The type of nano-drug delivery vehicle used to incorporate ivermectin influences its delivery both topically and transdermally, highlighting the dynamic equilibrium between the vehicle, the API and the skin.

Co-Processed Crystalline Solids of Ivermectin with Span® 60 as Solubility Enhancers of Ivermectin in Natural Oils

Despite being discovered over five decades ago, little is still known about ivermectin. Ivermectin has several physico-chemical properties that can result in it having poor bioavailability. In this study, polymorphic and co-crystal screening was used to see if such solid-state modifications can improve the oil solubility of ivermectin. Span® 60, a lipophilic non-ionic surfactant, was chosen as co-former. The rationale behind attempting to improve oil solubility was to use ivermectin in future topical and transdermal preparations to treat a range of skin conditions like scabies and head lice. Physical mixtures were also prepared in the same molar ratios as the co-crystal candidates, to serve as controls. Solid-state characterization was performed using X-ray powder diffraction (XRPD), Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The FTIR spectra of the co-crystal candidates showed the presence of Span® 60's alkyl chain peaks, which were absent in the spectra of the physical mixtures. Due to the absence of single-crystal X-ray data, co-crystal formation could not be confirmed, and therefore these co-crystal candidates were referred to as co-processed crystalline solids. Following characterization, the solid-state forms, physical mixtures and ivermectin raw material were dissolved in natural penetration enhancers, i.e., avocado oil (AVO) and evening primrose oil (EPO). The co-processed solids showed increased oil solubility by up to 169% compared to ivermectin raw material. The results suggest that co-processing of ivermectin with Span® 60 can be used to increase its oil solubility and can be useful in the development of oil-based drug formulations.

Investigation and Evaluation of the Transdermal Delivery of Ibuprofen in Various Characterized Nano-Drug Delivery Systems

The aim was to assess the suitability of three nano-based transdermal drug delivery systems containing ibuprofen: a nano-emulsion, a nano-emulgel, and a colloidal suspension with ibuprofen-loaded nanoparticles. Understanding the transdermal delivery of ibuprofen using nano-based drug delivery systems can lead to more effective pain relief and improved patient compliance. Characterization tests assessed the suitability of the developed drug delivery systems. Membrane release and skin diffusion studies, along with tape stripping, were performed to determine drug release and skin permeation of ibuprofen. In vitro cytotoxicity studies on HaCaT cells were conducted using MTT and neutral red assays to evaluate the safety of the developed drug delivery systems. Characterization studies confirmed stable drug delivery systems with ideal properties for transdermal delivery. Membrane release studies demonstrated the successful release of ibuprofen. In vitro skin diffusion experiments and tape stripping, detecting ibuprofen in the receptor phase, stratum corneum-epidermis, and epidermis-dermis, indicating successful transdermal and topical delivery. The in vitro cytotoxicity studies observed only minor cytotoxic effects on HaCaT cells, indicating the safety of the developed drug delivery systems. The investigation demonstrated promising results for the transdermal delivery of ibuprofen using the developed drug delivery systems, which contributes to valuable insights that may lead to improved pain management strategies.