Optimization of menthol-loaded nanocapsules for skin application using the response surface methodology

Core-Shell Type Lipidic and Polymeric Nanocapsules: the Transformative Multifaceted Delivery Systems

Amongst the several nano-drug delivery systems, lipid or polymer-based core-shell nanocapsules (NCs) have garnered much attention of researchers owing to its multidisciplinary properties and wide application. NCs are structured core-shell systems in which the core is an aqueous or oily phase protecting the encapsulated drug from environmental conditions, whereas the shell can be lipidic or polymeric. The core is stabilized by surfactant/lipids/polymers, which control the release of the drug. The presence of a plethora of biocompatible lipids and polymers with the provision of amicable surface modifications makes NCs an ideal choice for precise drug delivery. In the present article, multiple lipidic and polymeric NC (LNCs and PNCs) systems are described with an emphasis on fabrication methods and characterization techniques. Far-reaching applications as a carrier or delivery system are demonstrated for oral, parenteral, nasal, and transdermal routes of administration to enhance the bioavailability of hard-to-formulate drugs and to achieve sustained and targeted delivery. This review provide in depth understanding on core-shell NC's mechanism of absorption, surface modification, size tuning, and toxicity moderation which overshadows the drawbacks of conventional approaches. Additionally, the review shines a spotlight on the current challenges associated with core-shell NCs and applications in the foreseeable future.

Vanillic Acid as a Promising Xanthine Oxidase Inhibitor: Extraction from Amomum villosum Lour and Biocompatibility Improvement via Extract Nanoemulsion

Gout is an oxidative stress-related disease. Food-derived vanillic acid, a promising xanthine oxidase inhibitor, could potentially be used as a safe, supportive, and therapeutic product for gout. The extraction of vanillic acid from a classic Chinese herbal plant Amomum villosum with ethanol was investigated in the study. The optimum conditions were determined as extraction time of 74 min, extraction temperature of 48.36 °C, and a solid-to-liquid ratio of 1:35 g·mL⁻¹ using the Box–Behnken design (BBD) of response surface methodology (RSM). The experimental extraction yield of 9.276 mg·g⁻¹ matched with the theoretical value of 9.272 ± 0.011 mg·g⁻¹ predicted by the model. The vanillic acid in Amomum villosum was determined to be 0.5450 mg·g⁻¹ by high-performance liquid chromatography–diode array detection (HPLC–DAD) under the optimum extraction conditions and exhibited xanthine oxidase (XO) inhibitory activity, with the half-maximal inhibitory concentration (IC50) of 1.762 mg·mL⁻¹. The nanoemulsion of Amomum villosum extract consists of 49.97% distilled water, 35.09% S_mix (mixture of tween 80 and 95% ethanol with 2:1 ratio), and 14.94% n-octanol, with a particle size of 110.3 ± 1.9 nm. The nanoemulsion of Amomum villosum extract exhibited markable XO inhibitory activity, with an inhibition rate of 58.71%. The result demonstrated the potential benefit of Amomum villosum as an important dietary source of xanthine oxidase inhibitors for gout.

Optimization and Transfollicular Delivery of Finasteride-Loaded Proniosomes for Hair Growth Stimulation in C57BL/6Mlac Mice

The study aimed to develop the finasteride-loaded proniosome (FLP) to enhance the transfollicular delivery of finasteride (FN). The response surface methodology (RSM) combined with central composite design (CCD) with three independent variables (FN concentrations, total lipid content, and cholesterol content) was used to optimize the FLP preparation. The particles size, zeta potential, entrapment efficiency, and drug loading capacity of the FLP were analyzed. The transfollicular delivery of the optimum formulation was investigated in vitro. In vivo hair growth stimulation study was performed on C57BL/6Mlac mice dorsal areas. The Draize primary skin irritation test for erythema and edema was performed in the New Zealand white rabbit skin. The optimum FLP consists of 5.0 mM of FN, 10.1 mM of total lipid content, and 50.0% of the cholesterol in the total lipid. The prepared proniosome delivered the FN significantly (p < 0.05), compared to the naked finasteride solution in a dose- and time-dependent manner. The FLP treatment significantly increases the number and size of hair follicles in a dose-dependent manner. The efficiency of 1% FLP was comparable to the 2% minoxidil solution. The FLP exhibited no skin irritation after 72 h. Therefore, the results demonstrated that the FLP could stimulate hair growth via a transfollicular delivery system.

Pullulan film incorporated with nanocapsules improves pomegranate seed oil anti-inflammatory and antioxidant effects in the treatment of atopic dermatitis in mice

This study aimed to prepare pullulan films containing pomegranate seeds oil (PSO) based nanocapsules, and evaluate the formulation efficacy in the treatment of atopic dermatitis (AD)-like lesions induced by 2,4-dinitrochlorobenzene (DNCB). The Eudragit RS 100® nanocapsules (PSONC) were prepared by the interfacial precipitation of preformed polymer, whereas the films were produced by the solvent casting method. Pomegranate seed oil nanoemulsions (PSONE) were prepared by the spontaneous emulsification method for comparative reasons. Both nanosystems presented adequate mean diameter (248 ± 16 nm for PSONE and 181 ± 6 nm for PSONC), polydispersity index (below 0.2), zeta potential (-25.63 ± 1.1 mV for PSONE and + 43.13 ± 0.7 mV for PSONC) and pH in the acid range (6.77 ± 0.27 and 5.31 ± 0.17, PSONE and PSONC). By a pre-formulation study, sorbitol (6.5%) and PEG 400 (1.5%) were considered the most suitable plasticizers for developing pullulan films (6%) intending topical application. In general, pullulan films were classified as flexible and hydrophilic, with high occlusive properties, 57.6 ± 0.8%, 64.6 ± 0.8% for vehicle, PSONCF (pullulan film containing PSONC), respectively. All formulations (films and nanocarriers) presented no irritant potential in the chorioallantoic membrane test. In the in vivo model, the treatments with free PSO and PSONCF attenuated the skin injury as well as the mechanical hypernociceptive behavioral induced by DNCB exposure to mice. Importantly, the biochemical analyses provided evidence that only the treatment with PSONCF modulated the inflammatory and the oxidative stress parameters evaluated in this study. In conclusion, these data lead us to believe that PSONC incorporation into a pullulan film matrix improved the biological properties of the PSO in this AD-model.

Incorporation of nanocapsules into gellan gum films: A strategy to improve the stability and prolong the cutaneous release of silibinin

This study aimed to develop gellan gum films containing silibinin-loaded nanocapsules as a novel approach for cutaneous administration of this flavonoid. The nanocapsule suspensions were prepared and presented mean size around 140 nm with homogenous distribution, negative zeta potential and silibinin encapsulation efficiency close to 100%. Then, these suspensions were converted into gellan gum films by solvent casting method. The films were transparent, flexible and maintained the gellan gum hydrophilicity. Nanocapsules provided the silibinin homogenous distribution in the films and prolonged its release, as well as improved the gellan gum occlusion potential. Besides, the nanosuspensions conversion into films improved the silibinin stability. Additionally, the nano-based films presented a swelling index 1.5 times higher than films containing non-nanoencapsulated silibinin. Microscopic analysis evidenced the homogeneous surface of the nano-based films, while films containing non-nanoencapsulated silibinin presented small cracks. The in vitro skin permeation profile confirmed the silibinin gradual release from the nano-based films and its greater retention in the dermis when the skin is damaged. Finally, the formulations presented no irritant effect in the HET-CAM assay. Therefore, the conversion of silibinin-loaded nanocapsule suspensions into films might be considered a promising platform for skin delivery of this flavonoid.

Encapsulation of Flavours and Fragrances into Polymeric Capsules and Cyclodextrins Inclusion Complexes: An Update

Flavours and fragrances are volatile compounds of large interest for different applications. Due to their high tendency of evaporation and, in most cases, poor chemical stability, these compounds need to be encapsulated for handling and industrial processing. Encapsulation, indeed, resulted in being effective at overcoming the main concerns related to volatile compound manipulation, and several industrial products contain flavours and fragrances in an encapsulated form for the final usage of customers. Although several organic or inorganic materials have been investigated for the production of coated micro- or nanosystems intended for the encapsulation of fragrances and flavours, polymeric coating, leading to the formation of micro- or nanocapsules with a core-shell architecture, as well as a molecular inclusion complexation with cyclodextrins, are still the most used. The present review aims to summarise the recent literature about the encapsulation of fragrances and flavours into polymeric micro- or nanocapsules or inclusion complexes with cyclodextrins, with a focus on methods for micro/nanoencapsulation and applications in the different technological fields, including the textile, cosmetic, food and paper industries.

Description of Chiral Complexes within Functional-Group Symmetry-Adapted Perturbation Theory-The Case of (S/R)-Carvone with Derivatives of (-)-Menthol

Symmetry-adapted perturbation theory (SAPT) and functional-group SAPT (F-SAPT) are applied to examine differences in interaction energies of diastereoisomeric complexes of two chiral molecules of natural origin: (S/R)-carvone with (-)-menthol. The study is extended by including derivatives of menthol with its hydroxy group exchanged by another functional group, thus examining the substituent effect of the interaction and the interaction differences between diastereoisomers. The partitioning of the interaction energy into functional-group components allows one to explain this phenomenon by the mutual cancellation of attractive and repulsive interactions between functional groups. In some cases, one can identify dominant chiral interactions between groups of atoms of carvone and menthol derivatives, while in many other instances, no major interaction can be distinguished and the net chiral difference results from subtle near cancellation of several smaller terms. Our results indicate that the F-SAPT method can be faithfully utilized for such analyses.