Ethylcellulose microparticles enhance 3,3'-diindolylmethane anti-hypernociceptive action in an animal model of acute inflammatory pain.

AIM: The present work aimed at the DIM-loaded microparticles development and anti-hypernociceptive action evaluation. METHOD: The formulations were prepared by O/W solvent emulsion-evaporation method and characterised by particle diameter, content and DIM encapsulation efficiency, drug release profile, thermal behaviour and physicochemical state. The anti-hypernociceptive action was evaluated in the animal model of acute inflammatory pain. RESULT: The MPs had a mean diameter in the micrometric range (368 ± 31 µm), narrow size distribution, DIM content of 150 mg/g, encapsulation efficiency around 84% and prolonged compound release. Evaluations of the association form of DIM to MPs demonstrated the feasibility of the systems to incorporate DIM and increases its thermal stability. An improvement in the anti-hypernociceptive action of DIM was observed by its microencapsuation, because it was increased and prolonged. CONCLUSION: Therefore, the MPs developed represent a promising formulation for oral administration of the DIM in the treatment of inflammatory pain.

3,3'-Diindolylmethane nanoencapsulation improves its antinociceptive action: Physicochemical and behavioral studies.

This study aimed to characterize the physicochemical properties of 3,3'-diindolylmethane (DIM)-loaded nanocapsules (NCs) as well as the antinociceptive effect using distinct animal models (hot plate test, formalin-induced nociception and complete Freud's adjuvant induced paw inflammation). The DIM-loaded NCs (composed by primula oil and ethylcellulose) were characterized using differential scanning calorimetry, thermogravimetric analysis, Fourier-transformed infrared spectroscopy, X-ray diffractometry and scanning electron microscopy. The physicochemical characterization demonstrated that DIM could be molecularly dispersed into the NCs, whose size was nanometric with a spherical shape. An improvement in DIM thermal stability was achieved by its encapsulation and there were no interactions among the formula components. For the nociceptive evaluation, male adult Swiss mice were pretreated with the NCs or free DIM by the intragastric route at the dose of 10 mg/Kg (time-response curve), 5 or 2.5 mg/Kg (dose-response curve). The behavioral tests were performed over an experimental period of 0.5-8 h. Both free and nanoencapsulated DIM reduced the mechanical hypernociception induced by CFA, mitigated nociceptive behavior of formalin-induced neurogenic and inflammatory pain and increased paw withdrawal latency assessed by the hot-plate test. Importantly, the DIM nanoencapsulation promoted a rapid initiation and prolonged the bioactive antinociceptive action (up to 8 h) as well as reduced the effective dose in comparison to its free form. In summary, this study reported that the NCs had adequate nanometric size, increased DIM stability and its antinociceptive action in different animal models, suggesting that the formulation may be a possible therapeutic alternative to the management of pain and inflammatory-related pathologies.

Incorporation of 3,3'-Diindolylmethane into Nanocapsules Improves Its Photostability, Radical Scavenging Capacity, and Cytotoxicity Against Glioma Cells.

3,3'-Diindolylmethane (DIM) is a phytochemical that presents health benefits (antitumor, antioxidant, and anti-inflammatory effects). However, it is water insoluble and thermo- and photolabile, restraining its pharmaceutical applications. As a strategy to overcome such limitations, this study aimed the development and characterization of DIM-loaded nanocapsules (NCs) prepared with different compositions as well as the in vitro assessment of scavenging activity and cytotoxicity. The formulations were obtained using the interfacial deposition of preformed polymer method and were composed by Eudragit® RS100 or ethylcellulose as polymeric wall and primula or apricot oil as the core. All the formulations had adequate physicochemical characteristics: nanometric size (around 190 nm), low polydispersity index (< 0.2), pH value at acid range, high values of zeta potential, drug content, and encapsulation efficiency (~ 100%). Besides, nanoencapsulation protected DIM against UVC-induced degradation and increased the scavenging activity assessed by the 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) and 1-1-diphenyl-2-picrylhydrazyl methods. The developed DIM-loaded nanocapsules were further evaluated regarding the in vitro release profile and cytotoxicity against a human glioblastoma cell line (U87 cells). The results demonstrated that the nanoencapsulation promoted a sustained release of the bioactive compound (in the range of 58-78% after 84 h) in comparison to its free form (86% after 12 h), as well as provided a superior cytotoxic effect against the U87 cells in the highest concentrations. Therefore, our results suggest that nanoencapsulation could be a promising approach to overcome the DIM physicochemical limitations and potentialize its biological properties.

Improved photostability and cytotoxic effect of coenzyme Q10 by its association with vitamin E acetate in polymeric nanocapsules.

The present study showed the development of nanocapsules containing the association of the coenzyme Q10 and vitamin E acetate and the evaluation of their effect on in vitro cells culture of malignant glioma and melanoma. In order to investigate if nanocapsules are able to protect coenzyme Q10 from degradation under UVC radiation, a photostability study was carried out. For this, three concentrations of vitamin E acetate were evaluated (1%, 2%, or 3%). Nanocapsules presented suitable physicochemical characteristics and were able to protect coenzyme Q10 from photodegradation. In addition, this protection was influenced by higher vitamin E acetate concentrations, attributing to this oil an important role on coenzyme Q10 photostabilization. Regarding to in vitro citotoxicity assay, nanocapsules containing coenzyme Q10 and 2% vitamin E significantly reduced glioma and melanoma cell viability in 61% and 66%, respectively. In this sense, these formulations represent interesting platforms for the delivery of coenzyme Q10 and vitamin E acetate, presenting effect on the reduction of malignant cells viability.

Nanoencapsulation of coenzyme Q10 and vitamin E acetate protects against UVB radiation-induced skin injury in mice.

This study aimed to investigate the feasibility of producing semisolid formulations based on nanocapsule suspensions containing the association of the coenzyme Q10 and vitamin E acetate by adding gellan gum (2%) to the suspensions. Furthermore, we studied their application as an alternative for the treatment of inflammation induced by ultraviolet B (UVB) radiation. For this, an animal model of injury induced by UVB-radiation was employed. All semisolids presented pH close to 5.5, drug content above 95% and mean diameter on the nanometric range, after redispersion in water. Besides, the semisolids presented non-Newtonian flow with pseudoplastic behavior and suitable spreadability factor values. The results also showed that the semisolid containing coenzyme Q10-loaded nanocapsules with higher vitamin E acetate concentration reduced in 73±8% the UVB radiation-induced ear edema. Moreover, all formulations tested were able to reduce inflammation parameters evaluated through MPO activity and histological procedure on injured tissue and the semisolids containing the nanoencapsulated coenzyme Q10 reduced oxidative parameters assessment through the non-protein thiols levels and lipid peroxidation. This way, the semisolids based on nanocapsules may be considered a promising approach for the treatment and prevention of skin inflammation diseases.

Risedronate-loaded Eudragit S100 microparticles formulated into tablets.

Risedronate, an anti-osteoporotic drug, is associated with low patient compliance due to the upper gastrointestinal side-effects and stringent dosing regimes. This study aimed to prepare and characterize risedronate-loaded Eudragit® S100 microparticles and develop a final dosage form by the compression of microparticles using direct tableting excipients. Microparticles were prepared by spray-drying and presented yield of 54%, encapsulation efficiency higher than 90%, mean diameter of 3.3 µm, moisture content around 8% and exhibited spherical shape and poor flowability. At pH 1.2, 23% of risedronate was released from microparticles in 120 min, while at pH 6.8 the drug took 90 min to reach 99.5%. Microparticles were compressed into tablets using microcrystalline cellulose, magnesium stearate, colloidal silicon dioxide and 2 polyvinylpyrrolidone concentrations (5% and 15%). Tablets presented low variations in weight, thickness and drug content. Besides, the formulations showed sufficient hardness, low friability and disintegrated in less than 15 min. In acid medium, no more than 16% of the drug was released in 120 min, while in intestinal medium the formulations prolonged the risedronate release for 240 min. Finally, the developed tableted microparticles can be considered a promising dosage form for oral risedronate administration.

Clotrimazole-loaded Eudragit® RS100 nanocapsules: preparation, characterization and in vitro evaluation of antifungal activity against Candida species.

Clotrimazole is a common choice for the treatment of vulvovaginal infections, but its low solubility and some side effects pose a challenge to its application. This work evaluated the feasibility to formulate clotrimazole-loaded cationic nanocapsules using Eudragit® RS100 and medium chain triglycerides as polymer and oily core, respectively, by the method of interfacial deposition of a preformed polymer. The physicochemical characteristics of nanocapsule formulations were evaluated at 0 day and 60 days after preparation. Particle size, zeta potential, polydispersity index, pH and drug content were stable during this period. In addition, nanocapsules were able to protect clotrimazole from photodegradation under UV radiation. By the dialysis bag diffusion technique, the nanosized formulations showed prolonged release of clotrimazole by anomalous transport and first order kinetics. A microbiological study was carried out by the microdilution method and showed that nanocapsules (mean size: 144 nm; zeta potential: +12 mV) maintained the antifungal activity of clotrimazole against Candida albicans and Candida glabrata strains susceptible and resistant to fluconazole.