Nanoencapsulation potentiates the cutaneous anti-inflammatory effect of p,p'-methoxyl-diphenyl diselenide: Design, permeation, and in vivo studies of a nanotechnological-based carrageenan gum hydrogel.

This study aimed to investigate the feasibility of preparing a hydrogel based on (OMePhSe)2-loaded poly(Ɛ-caprolactone) nanocapsules using carrageenan gum as a gel-forming agent. Furthermore, the anti-inflammatory action of hydrogel was assessed in an animal model of skin lesion induced by ultraviolet B (UVB) radiation in mice. Nanocapsules were prepared using the interfacial deposition of preformed polymer technique. The hydrogels were obtained by the direct addition of nanocapsules suspension in carrageenan gum (3%). Formulations with free compound, vehicle, and blank nanocapsules were also produced. The hydrogels were characterized by pH, compound content, diameter, spreadability, rheological behavior, and permeation profile. The pharmacological performance was assessed in an animal model of skin injury induced by UVB-radiation in male Swiss mice. All hydrogels had pH around 7.0, compound content close to the theoretical value (2.5 mg/g), an average diameter in nanometric range (around 350 nm), non-Newtonian flow with pseudoplastic behavior, and suitable spreadability factor. The nano-based hydrogel increased the compound content in the epidermis and dermis layers in comparison to the formulation prepared with non-encapsulated (OMePhSe)2. Stability studies revealed that the hydrogels of nanoencapsulated compound had superior physicochemical stability in comparison to the formulation of free (OMePhSe)2. Moreover, topical treatment with the hydrogel containing (OMePhSe)2 loaded-nanocapsules was more effective in reducing ear thickness and the inflammatory process induced by UVB radiation in mice. Herein, a polysaccharide was applied as a gel-forming agent using a simple and low-cost method. Besides, a superior permeation profile and improved pharmacological action were achieved by the compound encapsulation.

Xanthan gum-based hydrogel containing nanocapsules for cutaneous diphenyl diselenide delivery in melanoma therapy.

The aim of this study was to further evaluate the antitumoral effect of (PhSe)2-loaded polymeric nanocapsules (NC (PhSe)2) against a resistant melanoma cell line (SK-Mel-103) and develop a xanthan gum-based hydrogel intending the NC (PhSe)2 cutaneous application. For the in vitro evaluation, cells were incubated with free (PhSe)2 or NC (PhSe)2 (0.7-200 µM) and after 48 h the MTT assay, propidium iodide uptake (necrosis marker) and nitrite levels were assessed. The hydrogels were developed by thickening of the NC (PhSe)2 suspension or (PhSe)2 solution with xanthan gum and characterized in terms of average diameter, polydispersity index, pH, drug content, spreadability, rheological profiles and in vitro permeation in human skin. The results showed that NC (PhSe)2 provided a superior antitumoral effect in comparison to free (PhSe)2 (IC50 value of 47.43 µM and 65.05 µM, respectively) and increased the nitrite content. Both compound forms induced propidium iodide uptake, suggesting a necrosis-related pathway could be involved in the cytotoxic action of (PhSe)2. All hydrogels showed pH values around 7, drug content close to the theoretical values (5 mg/g) and mean diameter in the nanometric range. Besides, formulations were classified as non-Newtonian flow with pseudoplastic behavior and suitable spreadability factor. Skin permeation studies revealed that the compound content was higher for the nano-based hydrogel in the dermis layer, demonstrating its superior permeation, achieved by the compound encapsulation. It is the first report on an adequate formulation development for cutaneous application of NC (PhSe)2 that could be used as an adjuvant treatment in melanoma therapy.

Copaiba oleoresin has topical antinociceptive activity in a UVB radiation-induced skin-burn model in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Copaiba oleoresin, extracted from Copaifera L., is used as a wound healing, analgesic, antimicrobial and, mainly, anti-inflammatory agent. Thus, in this study we investigated the antinociceptive and anti-inflammatory effects of a topical formulation containing Copaiba oleoresin (3%) in a UVB radiation-induced skin burn model (0.75 J/cm2) in mice and performed a cream-formulation stability study. MATERIALS AND METHODS: The chemical composition of Copaiba oleoresin was analyzed using gas chromatography (GC-MS). The topical antinociceptive (evaluated through mechanical allodynia and thermal hyperalgesia) and the anti-inflammatory (dermal thickness and inflammatory cell infiltration) effects of treatments were assessed. The cream-formulation stability study was performed after two months, and organoleptic characteristics, pH, spreadability and rheological characteristics were analyzed. RESULTS: Copaiba oleoresin cream was able to prevent UVB radiation-induced mechanical allodynia on the 2nd, 3rd and 4th day after UVB radiation exposure with a maximum inhibition (Imax) of 64.6 ± 7% observed on the 2nd day; it also reduced the thermal hyperalgesia on the 1st and 2nd days post UVB radiation, with a Imax of 100% observed on the 2nd day. Moreover, topical treatment with Copaiba oleoresin cream inhibited the inflammatory cell infiltration, but did not reduce the dermal thickness. Such effects can be attributed, at least in part, to the presence of biological components, such as ß-caryophyllene and other sesquiterpenes identified by GC-MS. CONCLUSION: Our results demonstrate that the topical formulation containing Copaiba oleoresin presented antinociceptive and anti-inflammatory effects in mice subjected to a UVB radiation and that the cream-formulation was stable for two months. Thus, use of Copaiba oleoresin is a promising strategy for the treatment of inflammatory pain associated with sunburn.

Hydrogel containing silibinin nanocapsules presents effective anti-inflammatory action in a model of irritant contact dermatitis in mice.

The current study developed an innovative Pemulen® TR2 hydrogel containing silibinin-loaded pomegranate oil-based nanocapsules (HP-NC SB) intending cutaneous application. The formulation anti-inflammatory activity in an in vivo model and biometric studies on the skin of healthy volunteers were also performed. The nanocapsules were prepared using the interfacial deposition of preformed polymer technique and the hydrogels were obtained by thickening of nanocapsules suspension with Pemulen® TR2. Formulations with free compound, vehicle and blank nanocapsules were also produced. The hydrogels were evaluated concerning pH, silibinin content, particle size, spreadability profile, rheology, in vitro drug release, cutaneous permeation, bioadhesive potential and cutaneous biometry evaluation. Furthermore, a model of contact dermatitis croton oil-induced in mice was performed to evaluate the hydrogels anti-inflammatory potential. The formulations presented adequate characteristics for skin administration: particle within nanometric size, pH values in the acid range, silibinin content close theoretical values (1 mg/g) and non-Newtonian pseudoplastic behavior. Nano-based hydrogels showed high bioadhesive properties, increased silibinin in vitro release profile and its retention in the stratum corneum. The best anti-inflammatory effect was exhibited by HP-NC SB, which reduced both ear edema and inflammatory cells infiltration in comparison to the induced group. Furthermore, cutaneous biometric evaluation showed that formulations containing free or nanoencapsulated silibinin caused no modification in normal skin conditions (pH, tissue hydration, transepidermal water loss and erythema). In summary, the results demonstrated that the Pemulen® TR2 hydrogel containing NC SB was successfully developed, indicating its potential as an alternative treatment for irritant contact dermatitis.

Hydrogel containing silibinin-loaded pomegranate oil based nanocapsules exhibits anti-inflammatory effects on skin damage UVB radiation-induced in mice.

The present study shows the development of a topical formulation (hydrogel) containing silibinin-loaded pomegranate oil based nanocapsules suspension and its evaluation as an alternative for the treatment of cutaneous UVB radiation-induced damages. For this, an animal model of skin injury induced by UVB radiation was employed. Gellan gum was used as gel forming agent by its direct addition to nanocapsules suspension. The hydrogels showed adequate pH values (5.6-5.9) and a silibinin content close to the theoretical value (1mg/g). Through vertical Franz diffusion cells it was demonstrated that nanocapsules decreased the silibinin retention in the semisolid formulation. All formulations were effective in reducing mice ear edema and leukocyte infiltration induced by UVB radiation 24h after the treatments. After 48h, only the hydrogels containing nanocapsules or silibinin associated with pomegranate oil demonstrated anti-edematogenic effect, as well as the positive control (hydrogel containing silver sulfadiazine 1%). After 72h, the hydrogel containing unloaded pomegranate oil based nanocapsules still presented a small activity. In conclusion, the results of this investigation demonstrated the feasibility to prepare a semisolid formulation presenting performance comparable to the traditional therapeutic option for skin burns (silver sulfadiazine) and with prolonged in vivo anti-inflammatory activity compared to the non-nanoencapsulated compounds.