Cannabidiol-Loaded Nanostructured Lipid Carriers (NLCs) for Dermal Delivery: Enhancement of Photostability, Cell Viability, and Anti-Inflammatory Activity

The aim of this study was to encapsulate cannabidiol (CBD) extract in nanostructured lipid carriers (NLCs) to improve the chemical stability and anti-inflammatory activity of CBD for dermal delivery. CBD-loaded NLCs (CBD-NLCs) were prepared using cetyl palmitate (CP) as a solid lipid and stabilized with Tego^® Care 450 (TG450) or poloxamer 188 (P188) by high-pressure homogenization (HPH). The CBD extract was loaded at 1% w/w. Three different oils were employed to produce CBD-NLCs, including Transcutol^® P, medium-chain triglycerides (MCT), and oleic acid (OA). CBD-NLCs were successfully prepared with an entrapment efficiency (E.E.) of 100%. All formulations showed particle sizes between 160 and 200 nm with PDIs less than 0.10. The type of surfactant and oil used affected the particle sizes, zeta potential, and crystallinity of the CBD-NLCs. CBD-NLCs stabilized with TG450 showed higher crystallinity after production and storage at 30 °C for 30 days as compared to those with P188. Encapsulation of the CBD extract in NLCs enhanced its chemical stability after exposure to simulated sunlight (1000 kJ/m²) compared to that of the CBD extract in ethanolic solution. The CBD-NLCs prepared from MCT and OA showed slower CBD release compared with that from Transcutol^® P, and the kinetic data for release of CBD from CBD-NLCs followed Higuchi's release model with a high coefficient of determination (>0.95). The extent of CBD permeation through Strat-M^® depended on the oil type. The cytotoxicity of the CBD extract on HaCaT and HDF cells was reduced by encapsulation in the NLCs. The anti-inflammatory activity of the CBD extract in RAW264.7 cell macrophages was enhanced by encapsulation in CBD-NLCs prepared from MCT and OA.

Development and optimization of a tamsulosin nanostructured lipid carrier loaded with saw palmetto oil and pumpkin seed oil for treatment of benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is a nonmalignant growth of the prostate tissue and causes urinary tract symptoms. To provide effective treatment, tamsulosin (TM), saw palmetto oil (SP), and pumpkin seed oil (PSO) were combined and fabricated a nanostructured lipid carrier (NLC) as TM-S/P-NLC using experimental design. The purpose was to enhance the permeation and therapeutic activity of TM; combining TM with SP and PSO in an NLC generates a synergistic activity. An optimized TM-S/P-NLC was obtained after statistical analysis, and it had a particle size, percentage of entrapment efficiency, and steady-state flux of 102 nm, 65%, and 4.5 μg/cm².min, respectively. Additionally, the optimized TM-S/P-NLC had spherical particles with a more or less uniform size and a stability score of 95%, indicating a high level of stability. The in vitro release studies exhibited the optimized TM-S/P-NLC had the maximum release profile for TM (81 ± 4%) as compared to the TM-NLCs prepared without the addition of S/P oil (59 ± 3%) or the TM aqueous suspension (30 ± 5%). The plasma TM concentration–time profile for the TM-S/P-NLC and the marketed TM tablets indicated that when TM was supplied in a TM-S/P-NLC, the pharmacokinetic profile of the drug was improved. Simultaneously, in vivo therapeutic efficacy studies also showed favorable results for the TM-S/P-NLC in terms of the prostate weight and prostate index following treatment of BPH. Based on the findings of present study, we suggest that in the future, the TM-S/P-NLC could be a novel drug delivery system for treating BPH.

Essential Oil-Loaded NLC for Potential Intranasal Administration

Complementary and alternative medicines represent an interesting field of research on which worldwide academics are focusing many efforts. In particular, the possibility to exploit pharmaceutical technology strategies, such as the nanoencapsulation, for the delivery of essential oils is emerging as a promising strategy not only in Italy but also all over the world. The aim of this work was the development of nanostructured lipid carriers (NLC) for the delivery of essential oils (Lavandula, Mentha, and Rosmarinus) by intranasal administration, an interesting topic in which Italian contributions have recently increased. Essential oil-loaded NLC, projected as a possible add-on strategy in the treatment of neurodegenerative diseases, were characterized in comparison to control formulations prepared with Tegosoft CT and Neem oil. Homogeneous (polydispersity index, PDI < 0.2) nanoparticles with a small size (<200 nm) and good stability were obtained. Morphological and physical-chemical studies showed the formation of different structures depending on the nature of the liquid oil component. In particular, NLC prepared with Lavandula or Rosmarinus showed the formation of a more ordered structure with higher cytocompatibility on two cell lines, murine and human fibroblasts. Taken together, our preliminary results show that optimized positively charged NLC containing Lavandula or Rosmarinus can be proposed as a potential add-on strategy in the treatment of neurodegenerative diseases through intranasal administration, due to the well-known beneficial effects of essential oils and the mucoadhesive properties of NLC.

Nanostructured lipid carriers containing chitosan or sodium alginate for co-encapsulation of antioxidants and an antimicrobial agent for potential application in wound healing

The high incidence and costs of chronic wounds in the elderly have motivated the search for innovations to improve product performance and the healing process while reducing costs. In this study, bioadhesive nanostructured lipid carriers (NLC) were developed for the co-encapsulation of compounds with antioxidant (α-tocopherol and quercetin) and antimicrobial (tea tree oil) activity for management of wounds. The NLC was produced with shea butter and argan oil, and modified with sodium alginate or chitosan to confer bioadhesive properties. Spherical nanoparticles of ~307-330 nm and zeta potential varying from -21.2 to +11.8 mV were obtained. Thermal analysis demonstrated that the lipid matrix reduced tea tree oil thermal loss (~1.8-fold). Regardless of the type of polysaccharide employed, the NLCs promoted cutaneous localization of antioxidants in damaged (subjected to incision) skin, with a ~74 to 180-fold higher delivery into the skin compared to percutaneous delivery. This result is consistent with the similar bioadhesive properties of chitosan or sodium alginate-modified NLC. Nanoencapsulation of tea tree oil did not preclude its antimicrobial effects against susceptible and resistant strains of S. aureus and P. aeruginosa, while co-encapsulation of antioxidants increased the NLC-induced fibroblasts migration, supporting their potential usefulness for management of wounds.