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Poly(hydroxybutyrate-co-hydroxyvalerate) (PHBHV) nanospheres and oily nanocapsules were prepared by emulsification–diffusion technique. Controlled particle sizes were obtained employing binary mixtures of solvents (chloroform:ethanol) in the organic phase. Ethanol was chosen because of its dipole–dipole interaction with chloroform and its hydrogen bond with water. The smallest particles (from 253 to 493 nm) were obtained using a mixture of solvents composed of 70% ethanol and 30% chloroform (v/v) in the organic phase, while the largest particles (from 896 to 1568 nm) were obtained using chloroform exclusively. Independently of the organic phase composition, the nanoparticles showed unimodal distributions. Optical microscopy showed that the size of the primary emulsion droplets of the nanosphere formulations decreased with increasing ethanol concentrations in the organic phase. A simple empirical equation was developed correlating the nanoparticle diameters with the surface tension gradient coefficient multiplied by the ethanol molar concentration in the organic phase. The strategy showed that the control of the nanoparticle diameters, using emulsification–diffusion technique, could be achieved by adjusting the surface tension of the organic phase.

The encapsulation of lipophilic drugs in polymeric nanoparticles can form simultaneously both polymeric nanoparticles and drug nanocrystals. The objective was to detect the presence of nanocrystals in the nanoparticle suspensions using a simple methodology, and to determine if the nanocrystals are formed during preparation or by drug leakage from the particles during storage. Indomethacin was chosen as drug model. Unloaded and drug-loaded (1 mg/mL) nanocapsules showed diameters close to 280 nm and polydispersity lower than 0.20, remaining constant after 120 days. Comparing indomethacin loaded (3 mg/mL) and unloaded formulations, variations in the scattered light depolarization degree indicated the simultaneous presence of nanocrystals and nanocapsules in the suspensions. A relation between the scattered light intensities and the drug precipitation was established. As a function of time, when the decrease in the Rayleigh ratios occurred, the drug contents decreased due to precipitation. On the other hand, when the Rayleigh ratios slightly increase, the drug contents are constant. The nanocrystals formed in the oversaturated formulations, agglomerate and precipitate during storage. When the drug is adsorbed on the nanocapsules, but the system is not oversaturated, no nanocrystal was formed and the formulation is physico-chemically stable at least for 150 days of storage.

The aim of this work was to evaluate the potentiality to control the drug release of a new architecture of microparticles organized at the nanoscopic scale by assembling polymeric nanocapsules at the surface of drug-loaded xerogels. Xerogel was prepared by sol-gel method using sodium diclofenac, as hydrophilic drug model, and coated by spray-drying. After coating, the surface areas decreased from 82 to 28 m(2)/g, the encapsulation efficiency was 71% and SEM analysis showed irregular microparticles coated by the nanocapsules. Formulation showed satisfactory gastro-resistance presenting drug release lower than 3% (60 min) in acid medium. In water, the pure drug dissolved 92% after 5 min, uncoated drug-loaded xerogel released 60% and nanocapsule coated drug-loaded xerogel 36%. After 60 min, uncoated drug-loaded xerogel released 82% and nanocapsule coated drug-loaded xerogel 62%. In conclusion, the new system was able to control the release of the hydrophilic drug model.

It has been recently shown that the association of melatonin with polymeric nanoparticles causes a significant increase of the in vitro effect against lipid peroxidation. Hence, the aim of the present study was to compare the in vivo acute antioxidant effect of intraperitoneal administration of melatonin-loaded polysorbate 80-coated nanocapsules with that of melatonin aqueous solution in mice brain (frontal cortex and hippocampus) and liver. The lipid peroxidation through thiobarbituric acid reactive substance levels, the total antioxidant reactivity (luminol-enhanced chemiluminescence) and the free radical levels (formed dichlorofluorescein) has been carried out. Our results show that a single melatonin aqueous solution injection exerted no antioxidant activity in the evaluated range, while the administration of the melatonin-loaded polysorbate 80-coated nanocapsules caused a marked reduction on lipid peroxidation levels in all studied tissues. No differences on free radical content were found in the tissues. The melatonin-loaded nanocapsules also increased the total antioxidant reactivity in the hippocampus. These in vivo results are in accordance with our previous in vitro findings and confirm the hypothesis that polymeric nanocapsules improve the antioxidant effect of melatonin against lipid peroxidation.

The aim of this work was to establish a quantitative correlation between the drug permeability and the polymer concentration in the nanocapsules. Indomethacin ethyl ester-loaded nanoemulsion and nanocapsules containing poly(epsilon-caprolactone) at different concentrations (0, 2, 4, 6, 8 and 10 mg/mL) presented drug loading between 0.981 and 1.005 mg/mL, pH values from 5.0 to 5.4, particle sizes between 232 and 261 nm, polydispersity lower than 0.24 and zeta potentials from − 8.54 mV to − 11.86 mV. An alkaline hydrolysis of indomethacin ethyl ester carried out at the particle/water interface was used to simulate a sink condition of release. The number of particles in each suspension was estimated. The calculated values ranged from 5.84 × 10 12 to 6.60 × 10 12 particles cm − 3 , showing similar concentration of particles in the formulations. The diffusion was proposed as the main mechanism of the indomethacin ester release after fitting the data to the Higuchi model. Applying the Fick's first law, the calculated indomethacin ester fluxes ( J ) decreased from 2.20 × 10 − 7 to 1.43 × 10 − 7 mg cm − 2 min − 1 . Then, the drug relative permeability decreased according to the increase in the polymer concentration fitting a power law.

The aim of this study was to prepare and characterize tretinoin-loaded nanocapsules as well as to evaluate the influence of this nanoencapsulation on tretinoin photostability. Tretinoin-loaded nanocapsules (0.5 mg ml(-1)) were prepared by interfacial deposition of preformed polymer (poly-epsilon-caprolactone) using two different oily phases: capric/caprylic triglycerides and sunflower seed oil. Tretinoin-loaded nanocapsules presented drug content close to the theoretical value, encapsulation efficiencies higher than 99.9%, nanometric mean size with a polydispersity index below 0.25, and pH values between 5.0 and 7.0. Regarding photodegradation studies, tretinoin methanolic solution showed a half-life time around 40 min according to a first order equation, whereas tretinoin nanocapsule suspensions showed a half-life between 85 and 100 min (twofold higher than in methanolic solution) according to a zero order equation. Tretinoin-loaded nanocapsules improved tretinoin photostability, independently on the type of oily phase used in this study, and represent a potential system to be incorporated in topical or systemic dosage forms containing tretinoin.

The objective of this work was to verify the influence of the poly(epsilon-caprolactone) PCL concentration in poly(hydroxybutyrate-co-hydroxyvalerate) P(HBHV)/PCL microparticles, prepared by an emulsion/solvent evaporation process, on the release behavior of a drug. Differential Scanning Calorimetry analyses demonstrated that the preparation process increased the crystallite heterogeneity for the P(HBHV) in the particles. The drug caused an increase in the glass transition of the P(HBHV) in the microparticles. Dexamethasone acetate-loaded microparticles demonstrated drug sustained releases (up to 250 h), which profiles fit the biexponential model. The release of dexamethasone acetate caused an increase in the surface area of the microparticles. The kinetic constants of the sustained phase increased with the augmentation of the PCL content in the blend. The drug release mechanism was dependent on the presence of PCL in the microparticles. A Fickian release was determined for the microparticles prepared exclusively with P(HBHV), while non-Fickian release behaviors were found for the P(HBHV)/PCL microparticles.

Quetiapine is an atypical antipsychotic used to treat schizophrenia. However, despite great interest for its chronic therapeutic use, quetiapine has some important side effects such as weight gain induction. The development of a quetiapine nanocarrier can potentially target the drug into central nervous system, resulting in a reduction of systemic side effects and improved patient treatment. In the present work, a simple liquid chromatography/ultraviolet detection (LC/UV) analytical method was developed and validated for quantification of total quetiapine content in lipid core nanocapsules as well as for determination of incorporation efficiency. An algorithm proposed by Oliveira et al. (2012) was applied to characterize the distribution of quetiapine in the pseudo-phases of the nanocarrier, leading to a better understanding of the quetiapine nanoparticles produced. The analytical methodology developed was specific, linear in the range of 0.5 to 100 µg mL−1 (r2 > 0,99), and accurate and precise (R.S.D < ±5%). The absolute recovery of quetiapine from the nanoparticles was approximately 98% with an incorporation efficiency of approximately 96%. The results indicated that quetiapine was present in a type III distribution according to the algorithm, and was mainly located in the core of the nanoparticle because of its logD in the formulation pH (6.86 ± 0.4).

Lipid-core nanocapsules (LNC) were designed and prepared as a colloidal system for drug targeting to improve the stability of drugs and allow their controlled release. For parenteral administration, it is necessary to ensure formulation sterility. However, sterilization of nanotechnological devices using an appropriate technique that keeps the supramolecular structure intact remains a challenge. This work aimed to evaluate the effect of autoclaving on the physicochemical characteristics of LNC. Formulations were prepared by the self-assembling method, followed by isotonization and sterilization at varying times and temperatures. The isotonicity was confirmed by determining the freezing temperature, which was -0.51°C. The formulation was broadly characterized, and the diameter of the particles was determined utilizing complementary methods. To evaluate the chemical stability of poly(e-caprolactone), its molecular weight was determined by size exclusion chromatography. The physicochemical characteristics (average diameter, viscosity, and physical stability) of the formulation were similar before and after adding glycerol and conducting the sterilization at the highest temperature (134°C) and the shorter exposure time (10 min). After autoclaving, the sterility test was performed and showed no detectable microbial growth. Multiple light scattering demonstrated that the formulations were kinetically stable, and the mean diameter was constant for 6 months, corroborating this result. The polymer was chemically stable in the sterilized formulation. Isotonic and sterile LNC aqueous suspensions were produced using glycerol and autoclaving. Briefly, the results open an opportunity to produce an isotonic and sterile LNC aqueous dispersion applicable as nanomedicine for intravenous administration in clinical trials.

Nanotoxicology aims to study the safety of nanomaterials, especially towards human exposure. Biodegradable polymeric nanocapsules have been indicated as potential drug carriers applicable for treating several pathologies. Thus, the objective of this study was to evaluate the potential cardiotoxicity of biodegradable lipid-core nanocapsules (LNC) containing poly(e-caprolactone). Nanocapsules were characterized and the acute toxicity evaluation was conducted in Wistar rats. Two control groups (saline and tween/glycerol) were utilized, and three treated groups were chosen for low, intermediate and high doses: 28.7 × 1012 (LNC-1), 57.5 × 1012 (LNC-2) and 115 × 1012 (LNC-3), expressed as number of nanocapsules per milliliter per kg. Blood pressure measurements were performed in non-anesthetized animals by caudal plethysmography. The electrocardiographic (ECG) and echocardiographic analyses were carried out after anesthesia by isoflurane at two points, prior to treatment and after 14 days. Blood was collected 24 hours and 14 days after treatment. Biochemical and histopathological analyses were performed. During the evaluation period, no deaths, weight loss or clinical signs were observed. Post-treatment systolic pressures (24 h and 14 days) were significantly increased in comparison to pre-treatment in both control groups and treated groups, which is suggested to be as a possible consequence of the infused volume. Serum sodium, potassium, aspartate aminotransferase and alkaline phosphatase, as well as, hematological parameters were within reference values established for rats. ECG showed no indications of cardiotoxicity. Despite the echocardiograms, no alterations in the ejection fraction were found as indicators of cardiotoxicity. Cardiac histopathology also demonstrated no alterations. Therefore, the present results on acute evaluation after i.v. administration, by slow infusion, showed potential safety since no cardiotoxic effects by ECG, echocardiographic, arterial pressure, biochemical and histopathological analyses were found.

Glioblastoma multiforme (GBM) is a deadly cancer characterized by a pro-tumoral immune response. T-regulatory (Treg) lymphocytes suppress effector immune cells through cytokine secretion and the adenosinergic system. Ecto-5'-nucleotidase/CD73 plays a crucial role in Treg-mediated immunosuppression in the GBM microenvironment (GME). Methotrexate (MTX) is an immunosuppressive drug that can increase the extracellular concentration of adenosine. In this manuscript, C6 GBM cells were treated with 1.0 μM MTX, and ecto-5'-nucleotidase/CD73 expression and extracellular AMP metabolism were analyzed in vitro. For in vivo studies, rats with implanted GBM were treated for 10 days with MTX-loaded lipid-core nanocapsules (MTX-LNCs, 1 mg/kg/day). The activity of ectonucleotidase and the expression of NTPDase1/CD39 and ecto-5'-nucleotidase/CD73 were measured. The frequencies of T lymphocytes (CD3(+)CD4(+), CD3(+)CD8(+), and CD4(+)CD25(high)CD39(+)) were quantified. In vitro, treatment with MTX increased CD73 expression and activity in C6 cells, which is in agreement with higher levels of extracellular adenosine. In vivo, MTX-LNC treatment increased CD39 expression on CD3(+)CD8(+) lymphocytes. In addition, MTX-LNC treatment up-regulated CD73 expression in tissue isolated from GBM, a finding that is in agreement with the higher activity of this enzyme. More specifically, the treatment increased CD73 expression on CD3(+)CD4(+) and CD3(+)CD8(+) lymphocytes. Treatment with MTX-LNCs decreased the frequencies of T-cytotoxic, T-helper, and Treg lymphocytes in the GME. Although more studies are necessary to better understand the complex cross-talk mediated by supra-physiological concentrations of adenosine in the GME, these studies demonstrate that MTX treatment increases CD73 enzyme expression and AMP hydrolysis, leading to an increase in adenosine production and immunosuppressive capability.

Lecithin and hyaluronic acid were used for the preparation of polysaccharide decorated nanoparticles loaded with vitamin E using the cationic lipid dioctadecyldimethylammonium bromide (DODMA). Nanoparticles showed mean particle size in the range 130-350 nm and narrow size distribution. Vitamin E encapsulation efficiency was higher than 99%. These nanoparticles were incorporated in polymeric films containing Aloe vera extract, hyaluronic acid, sodium alginate, polyethyleneoxide (PEO) and polyvinylalcohol (PVA) as an innovative treatment in skin wounds. Films were thin, flexible, resistant and suitable for application on burn wounds. Additionally, in vitro occlusion study highlighted the dependence of the occlusive effect on the presence of nanoparticles. The results obtained show that the bioadhesive films containing vitamin E acetate and Aloe vera could be an innovative therapeutic system for the treatment of skin wounds, such as burns. The controlled release of the vitamin along with a reduction in water loss through damaged skin provided by the nanoparticle-loaded polymer film are considered important features for an improvement in wound healing and skin regeneration.

In this study, two types of cutaneous-directed nanoparticles are proposed for the co-encapsulation of imiquimod (a drug approved for the treatment of basal cell carcinoma) and copaiba oil (oil that exhibits anti-proliferative properties). Nanostructured copaiba capsules (NCCImq) were prepared using the interfacial deposition method, and nanostructured Brazilian lipids (NBLImq) were prepared by high-pressure homogenization. The formulations exhibited average diameter, zeta potential, pH and drug content of approximately 200nm, -12mV, 6 and 1mgmL(-1), respectively. In addition, the formulations exhibited homogeneity regarding particle size, high encapsulation efficiency and stability. Both nanocarriers controlled imiquimod release, and NBLImq exhibited slower drug release (p < 0.05), likely due to increased interaction of the drug with the solid lipid (cupuacu seed butter). The in vitro evaluation of the imiquimod-loaded nanocarriers was performed using healthy skin cells (keratinocytes, HaCaT); no alteration was observed, suggesting the biocompatibility of the nanocarriers. In addition, in vitro skin permeation/penetration using pig skin was performed, and NCCImq led to increased drug retention in the skin layers and reduced amounts of drug found in the receiver solution. Thus, NCCImq is considered the most promising nanoformulation for the treatment of skin carcinoma.

Resveratrol and curcumin are two natural polyphenols extensively used due to their remarkable anti-inflammatory activity. The present work presents an inedited study of the in vivo antioedematogenic activity of these polyphenols co-encapsulated in lipid-core nanocapsules on Complete Freund's adjuvant (CFA)-induced arthritis in rats. Lipid-core nanocapsules were prepared by interfacial deposition of preformed polymer. Animals received a single subplantar injection of CFA in the right paw. Fourteen days after arthritis induction, they were treated with resveratrol, curcumin, or both in solution or loaded in lipid-core nanocapsules (1.75 mg/kg/twice daily, i.p.), for 8 days. At the doses used, the polyphenols in solution were not able to decrease paw oedema. However, nanoencapsulation improved the antioedematogenic activity of polyphenols at the same doses. In addition, the treatment with co-encapsulated polyphenols showed the most pronounced effects, where an inhibition of 37-55% was observed between day 16 and 22 after arthritis induction. This treatment minimized most of the histological changes observed, like fibrosis in synovial tissue, cartilage and bone loss. In addition, unlike conventionally arthritis treatment, resveratrol and curcumin co-encapsulated in lipid-core nanocapsules did not alter important hepatic biochemical markers (ALP, AST, and ALT). In conclusion, the strategy of co-encapsulating resveratrol and curcumin in lipid-core nanocapsules improves their efficacy as oedematogenic agents, with no evidence of hepatotoxic effects. This is a promising strategy for the development of new schemes for treatment of chronic inflammation diseases, like arthritis.

The rose-hip oil holds skin regenerating properties with applications in the dermatological and cosmetic area. Its nanoencapsulation might favor the oil stability and its incorporation into hydrophilic formulations, besides increasing the contact with the skin and prolonging its effect. The aim of the present investigation was to develop suitable rose-hip-oil-loaded nanocapsules, to verify the nanocapsule effect on the UV-induced oxidation of the oil and to obtain topical formulations by the incorporation of the nanocapsules into chitosan gel and film. The rose-hip oil (500 or 600 μL), polymer (Eudragit RS100®, 100 or 200 mg), and acetone (50 or 100 mL) contents were separately varied aiming to obtain an adequate size distribution. The results led to a combination of the factors acetone and oil. The developed formulation showed average diameter of 158 ± 6 nm with low polydispersity, pH of 5.8 ± 0.9, zeta potential of +9.8 ± 1.5 mV, rose-hip oil content of 54 ± 1 μL/mL and tendency to reversible creaming. No differences were observed in the nanocapsules properties after storage. The nanoencapsulation of rose-hip oil decreased the UVA and UVC oxidation of the oil. The chitosan gel and film containing rose-hip-oil-loaded nanocapsules showed suitable properties for cutaneous use. In conclusion, it was possible to successfully obtain rose-hip-oil-loaded nanocapsules and to confirm the nanocapsules effect in protecting the oil from the UV rays. The chitosan gel and film were considered interesting alternatives for incorporating the nanoencapsulated rose-hip oil, combining the advantages of the nanoparticles to the advantages of chitosan.

The objective of this study was to develop lycopene-loaded lipid-core nanocapsules (Lyc-LNCs) by the interfacial deposition of preformed poly(e-caprolactone) (PCL). Lyc extract (93.9 %) was obtained from tomatoes, and the organic phase was prepared with polymer (PCL), caprylic/capric triglycerides, sorbitan monostearate, and Lyc in a mixture of acetone and ethanol under magnetic stirring at 40 °C. The organic phase was injected into an aqueous phase containing polysorbate 80, and the suspension was concentrated under reduced pressure. The formulation with a Lyc concentration of 85 µg/mL was characterized in terms of size distribution, zeta potential, encapsulation efficiency, pH, viscosity, and color. The Lyc-LNC formulation presented stable values for the z-average (193 ± 4.7 nm) and zeta potential (−11.5 ± 0.40 mV). Despite the lower pH, Lyc content, and color change of the suspension, the nanocapsules showed satisfactory stability, presenting around 50 % Lyc content after 14 days of storage at room temperature (25 °C).

Nanocapsule suspensions containing melatonin were prepared by interfacial deposition method and characterized (size, morphological aspect and encapsulation efficiency). The formulation parameters studied were the oil nature, the type of surfactants and the type of polymer. The melatonin-encapsulation efficiency ranged between 30% and 56% and polymer nature was the parameter that more influenced the characteristics of suspensions. According to the highest encapsulation efficiency, the nanocapsules prepared with Eudragit S100® were selected to be spray-dried in order to improve the physical stability of suspension and to control the release of melatonin. The melatonin-loaded nanocapsule spray-dried powder presented encapsulation efficiency of the 93% and no morphological alterations were observed after 12 months of storage. This system showed a controlled release profile in comparison to the dissolution of the pure melatonin. The release profile was fitted to monoexponential model and the melatonin release mechanism was based on swelling and dissolution of the polymer. Suspensões de nanocápsulas contendo melatonina foram preparadas pelo método de deposição interfacial e caracterizadas (tamanho, morfologia e eficiência de encapsulação). Foram avaliadas as influências do tipo de polímero, de óleo e de tensoativo sobre as características dos produtos. A eficiência de encapsulação da melatonina variou de 30% a 56% e a natureza do polímero foi o parâmetro de maior influência. De acordo com a maior eficiência de encapsulação, nanocápsulas preparadas com Eudragit S100® foram selecionadas para secagem por aspersão, objetivando-se aumentar a estabilidade física das suspensões e controlar a liberação da melatonina. O pó obtido apresentou eficiência de encapsulação de 93% e não sofreu nenhuma alteração morfológica após 12 meses de armazenamento. Este sistema apresentou perfil de liberação controlado, comparativamente ao fármaco puro, o qual foi ajustado ao modelo monoexponencial. O mecanismo de liberação da melatonina foi baseado em intumescimento e dissolução do polímero.

The aim of this work was to establish models and to differentiate the kinetic release behavior of drug models from nanocapsules, nanoemulsion and nanospheres by physico-chemical characterization and release experiments. SAXS analysis showed that the polymer is organized in the nanocapsules, while in the nanospheres the sorbitan monostearate is organized and acts as an impurity of the poly(epsilon-caprolactone) suggesting that constituents in these nanocarriers are differently organized. Formulations presented particle sizes ranging from 178 to 297 nm, probe content from 0.981 to 0.997 mg/mL, pH values from 4.90 to 5.10 and zeta potential from -37.9 to -51.9 mV. The kinetic experiments showed that the nanostructures present similar behaviors when the probe is adsorbed on the nanocarriers (indomethacin-loaded formulations). However, when the probe is entrapped within the nanocarriers (indomethacin ethyl ester-loaded formulations), nanocapsules, nanospheres and nanoemulsion presented different kinetic behaviors. Mathematical modeling of the release profiles was conducted, showing that the presence of the polymer increases the half-lives of the burst phases (5.9, 4.4 and 2.7 min) while the presence of the oil increases the half-lives of the sustained phases (288.8, 87.7 and 147.5 min) for nanocapsules, nanospheres and nanoemulsion, respectively.

The aim of this study was to prepare melatonin-loaded nanoparticles (nanocapsules and nanospheres) by nanoprecipitation, using Eudragit S100® as polymer. The potential of these systems to protect lipids against peroxidation was evaluated in comparison to melatonin in aqueous solution and nanoemulsion. Liposomes and microsomes were used as model of a lipid membrane and lipid peroxidation was induced by free radical ascorbyl. Nanocapsule and nanosphere suspensions presented total recoveries of melatonin near 100% and associated drug around 55%. The zeta potential values were negative and the hydrodynamic diameter of particles were lower than 255 nm. The results demonstrate that the lipids were protected against peroxidation from 8 to 51% due to the presence of the melatonin and that this effect depended on the drug dose, the type of the lipid substrate and the type of colloid, in which melatonin was incorporated. Nanocapsules and nanospheres provided an important increase in the antioxidant effect of melatonin against lipid peroxidation.

To determine the association form of indomethacin in nanocapsules prepared with poly(e-caprolactone) as polymer and a triglyceride as oil, two methods were studied. The indomethacin ethyl ester was prepared as control, which showed a higher affinity for the oil than the indomethacin. Two differently loaded nanocapsule formulations were prepared. For both formulations, a burst effect was detected using ethanol as release medium. Light scattering (PCS) and NMR analyses suggested the ethanol diffuses through the nanocapsule polymeric wall promoting the total release of indomethacin and its ester. The results showed the inability of this approach to determine the association form of indomethacin. On the other hand, the alkaline hydrolysis of indomethacin and its ester, followed by their disappearance (HPLC), were evaluated. The nanocapsule suspensions containing indomethacin or its ester were treated with 50 mM NaOH. The total disappearance of indomethacin associated with nanocapsules was determined after 2 min, whereas the ester associated with colloids was consumed during 24 h. The constant particle sizes (264 and 259 nm) during the hydrolysis reactions showed that neither the nanocapsules were dissolved nor the polymer sorbed water during the contact with NaOH aqueous solution. The ester rate hydrolysis was determined by its diffusion from the nanocapsules to the interface particle / water. Finally, the indomethacin association model considers the burst release of drug after the addition of NaOH by the formation of its carboxylate, followed by its hydrolysis in aqueous solution promoted by the excess of NaOH. The adsorption was the mechanism of indomethacin association with nanocapsules.

Different polymeric nanoparticles were freeze-dried and the powders compared to determine the influence of the lipophilic core (Miglyol 810) or benzyl benzoate) and polymeric material (poly(epsilon-caprolactone) or Eudragit S90) on their drug content and morphology. Diclofenac, a non-steroidal anti-inflammatory drug, was used as a model. To characterize the products, a biological experiment based on the evaluation of the mucosal toxicity of diclofenac was conducted. Nanocapsule and nanosphere suspensions were prepared by nanoprecipitation and freeze-dried after the addition of colloidal silicon dioxide. The powders were examined under scanning electron microscopy (SEM) and gastrointestinal tolerance of products was evaluated in rats. Powders presented drug contents between 90.2+/-5.5 and 101.1+/-1.9% (HPLC). SEM analyzes showed non-spherical microparticles and, at higher magnifications, the micro-powder surface presented a homogeneous nanocovering. Regarding the gastrointestinal tolerance, with the exception of benzyl benzoate-loaded formulations, powders presented lesional indexes lower than the diclofenac salt solution. In contrast to the literature, nanocapsules can be dried by freeze-drying without leakage of drug or breaking the capsule wall.

Due to instability in the GI tract and low intestinal permeability, peptides invariably have oral bioavailabilities below 1% and this has prevented the development of oral formulations. A mild plant-derived naturalalkyl polyglycoside (APG), coco-glucoside (CG), was studied for its capacity to enable rat intestinal permeation of the paracellular sugar marker, fluorescein isothiocyanate-dextran 4000 (FD4), across isolated rat jejunal and colonic mucosae mounted in Ussing chambers, as well as the polypeptide, salmon calcitonin (sCT) following intra-intestinal instillations in rats. 0.1% (w/v) CG enabled a 2.9-fold increase in the apparent permeability coefficient (Papp) of FD4 over the basal Papp across colonic mucosae, but it was without effect in jejunal mucosae. In situ intestinal instillations revealed that although sCT was absorbed across rat colonic loops to a greater extent than jejunal, CG still improved sCT absolute bioavailability(F) from both segments. Histopathology of rat intestinal mucosae following exposure to CG indicated only minor perturbation with adequate maintenance of secretory function. High content analysis(HCA) on Caco-2 showed that acute and chronic exposure to a range of concentrations of CG did not cause sub-lethal damage at concentrations at which it was effective as an enhancer. Overall, CG increased bioavailability of sCT across rat jejunal and colonic loops without indication of tissue damage. Thus, CG has potential as a safe and effective intestinal enhancer for oral delivery of proteins and peptides.

Liposomal dry powders of N-acetylcysteine (SD-NAC-Lip) were developed for pulmonary administration. Liposomes were prepared by reverse phase evaporation and spray dried using lactose (10%, w/w) as drying adjuvant. The powders were characterized according to process yield, drug content, residual water content, particle size distribution, morphology and redispersion behavior. In vitro aerosol performance was evaluated using an eight-stage Andersen Cascade Impactor. Moreover, in vitro antioxidant activity was determined by measuring thiobarbituric acid reactive species (TBARS) present in the lungs of healthy Wistar rats after induction of oxidation by iron/EDTA. The spray-drying process had a high yield (71%±2), drug content (mg/g) according to the expected value, moisture content below 9%, geometric mean diameter under 3μm with span value lower than 1. Spherical particles were observed by scanning electron microscopy. Liposomal dry-powders were able to recover the nanometric size of the original dispersion after their redispersion in aqueous medium, as shown by laser diffraction and transmission electron microscopy. Furthermore, the powders presented aerodynamic diameter of about 7μm and respirable fraction above 30%, indicating suitable properties for pulmonary use. The encapsulation of N-acetylcysteine in liposomes was essential to maintain its in vitro antioxidant activity after the drying process. In addition, the powder containing the encapsulated drug had better in vitro antioxidant activity than the liquid and solid formulations containing the non-encapsulated drug, which makes it a good candidate for the treatment of pulmonary diseases associated with oxidative stress.

Olanzapine is an atypical antipsychotic drug, whose chronic use has been associated with the development of potential adverse effects such as weight gain and cardio-metabolic disorders like hypercholesterolemia and diabetes. To circumvent these side effects, the controlled release of olanzapine is a promising approach to improve adhesion of schizophrenic patients to the treatment. An innovative strategy to prolong drug release consists of loading the drug into biodegradable polymeric lipid-core nanocapsules. In this study, particle size, polydispersity, pH, zeta potential and drug loading of olanzapine-loaded lipid-core nanocapsules were analyzed. Weight gain, biochemical parameters and antipsychotic activity were evaluated in male Wistar rats. The lipid-core nanocapsules had a mean diameter of 156 +/- 13 nm, a polydispersity index lower than 0.1, a pH value of 6.12 +/- 0.14, zeta potential of -17 +/- 2.40 mV and encapsulation efficiency close to 100%. The animals treated with olanzapine-loaded lipid-core nanocapsules showed significantly lower weight gain (63.4 +/- 19.6 g) and total cholesterol levels (66.2 +/- 3.5 g x dl(-1)), compared to those administered with free olanzapine (112.6 +/- 10.3 g and 90.4 +/- 2.4 g x dl(-1)), respectively. Additionally, a more prolonged antipsychotic action was observed in the stereotyped behavior animal model induced by D,L-amphetamine, which affords to conclude that nanoencapsulation is a promising alternative to treat schizophrenic patients.

Virginia C Yurgel,1,* Catiuscia P Oliveira,2,* Karine R Begnini,1 Eduarda Schultze,1 Helena S Thurow,1 Priscila MM Leon,1 Odir A Dellagostin,1 Vinicius F Campos,1 Ruy CR Beck,2 Silvia S Guterres,2 Tiago Collares,1 Adriana R Pohlmann,2–4 Fabiana K Seixas11Programa de Pós-Graduação em Biotecnologia (PPGB), Grupo de Pesquisa em Oncologia Celular e Molecular, Laboratório de Genômica Funcional, Biotecnologia/Centro de Desenvolvimento Tecnológico, Universidade Federal de Pelotas, Pelotas, Rio Grande do Sul, Brazil; 2Programa de Pós-Graduação em Ciências Farmacêuticas, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil; 3Departamento de Química Orgânica, Instituto de Química, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil; 4Centro de Nanociência e Nanotecnologia, CNANO-UFRGS, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil*These authors contributed equally to this workAbstract: Breast cancer is the most frequent cancer affecting women. Methotrexate (MTX) is an antimetabolic drug that remains important in the treatment of breast cancer. Its efficacy is compromised by resistance in cancer cells that occurs through a variety of mechanisms. This study evaluated apoptotic cell death and cell cycle arrest induced by an MTX derivative (MTX diethyl ester [MTX(OEt)2]) and MTX(OEt)2-loaded lipid-core nanocapsules in two MTX-resistant breast adenocarcinoma cell lines, MCF-7 and MDA-MB-231. The formulations prepared presented adequate granulometric profile. The treatment responses were evaluated through flow cytometry. Relying on the mechanism of resistance, we observed different responses between cell lines. For MCF-7 cells, MTX(OEt)2 solution and MTX(OEt)2-loaded lipid-core nanocapsules presented significantly higher apoptotic rates than untreated cells and cells incubated with unloaded lipid-core nanocapsules. For MDA-MB-231 cells, MTX(OEt)2-loaded lipid-core nanocapsules were significantly more efficient in inducing apoptosis than the solution of the free drug. S-phase cell cycle arrest was induced only by MTX(OEt)2 solution. The drug nanoencapsulation improved apoptosis induction for the cell line that presents MTX resistance by lack of transport receptors.Keywords: MTX derivative, resistance, apoptotic cell death, cell cycle arrest, nanocarriers, drug delivery, drug targeting

Renata V Contri,1 Luiza A Frank,2 Moacir Kaiser,1 Adriana R Pohlmann,1,3 Silvia S Guterres1,2 1Programa de Pós-Graduação em Ciências Farmacêuticas, 2Faculdade de Farmácia, 3Instituto de Química, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil Abstract: Capsaicin, a topical analgesic used in the treatment of chronic pain, has irritant properties that frequently interrupt its use. In this work, the effect of nanoencapsulation of the main capsaicinoids (capsaicin and dihydrocapsaicin) on skin irritation was tested in humans. Skin tolerance of a novel vehicle composed of chitosan hydrogel containing nonloaded nanocapsules (CH-NC) was also evaluated. The chitosan hydrogel containing nanoencapsulated capsaicinoids (CH-NC-CP) did not cause skin irritation, as measured by an erythema probe and on a visual scale, while a formulation containing free capsaicinoids (chitosan gel with hydroalcoholic solution [CH-ET-CP]) and a commercially available capsaicinoids formulation caused skin irritation. Thirty-one percent of volunteers reported slight irritation one hour after application of CH-NC-CP, while moderate (46% [CH-ET-CP] and 23% [commercial product]) and severe (8% [CH-ET-CP] and 69% [commercial product]) irritation were described for the formulations containing free capsaicinoids. When CH-NC was applied to the skin, erythema was not observed and only 8% of volunteers felt slight irritation, which demonstrates the utility of the novel vehicle. A complementary in vitro skin permeation study showed that permeation of capsaicinoids through an epidermal human membrane was reduced but not prevented by nanoencapsulation. Keywords: chitosan, nanocapsules, capsaicinoids, skin irritation, skin permeation

Luiza A Frank,1 Giuseppina Sandri,2 Francesca D´Autilia,2 Renata V Contri,1 Maria Cristina Bonferoni,2 Carla Caramella,2 Alejandro G Frank,3 Adriana R Pohlmann,1 Silvia S Guterres11Pharmaceutical Science Graduate Program, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil; 2Department of Drug Sciences, University of Pavia, Pavia, PV, Italy; 3Department of Industrial Engineering, Federal University of Rio Grande do Sul, Porto Alegre, RS, BrazilAbstract: The vaginal route of administration is an alternative for several treatments for either local or systemic pharmacological effects. However, the permanence of a drug in this route represents a challenge for formulation development that can be overcome by using nanoencapsulation and chitosan gel. Thus, this work aimed to evaluate the performance of chitosan hydrogels containing cationic and anionic acrylic-based nanocapsules (Eudragit® RS100 and Eudragit® S100, respectively) with Nile red as a model of lipophilic substance in the vaginal route of administration, as measured by increases in the residence time and the penetration of these formulations. Several formulations were prepared with increasing chitosan concentrations, and were analyzed in terms of pH and rheological behavior so that the most suitable formulation could be selected. The enhancement of the adhesion (tensile stress test and washability profile) and penetration (confocal laser scanning microscopy and extraction followed by quantification) properties of the formulations, when applied to porcine vaginal mucosa, were evaluated. The nanocapsule suspensions produced presented adequate properties: size of approximately200nm (polydispersity index of ≤0.2); zeta potential around +10mV for the cationic formulation and -10mV for the anionic formulation; and pH values of6.1±0.1(Eudragit RS 100),5.3±0.2(Eudragit S 100),6.2±0.1(Nile red loaded Eudragit RS 100), and5.1±0.1(Nile red loaded Eudragit S 100). The chitosan formulation presented suitable viscosity for vaginal application and acidic pH (approximately4.5). The tensile stress test showed that both formulations containing polymeric nanocapsules presented higher mucoadhesion when compared with the formulation without nanocapsules. In the washability experiment, no significant differences were found between formulations. Confocal microscopy and fluorescence quantification after extraction from the mucosa showed higher penetration of Nile red when it was nanoencapsulated, particularly in cationic nanocapsules. The formulations developed based on chitosan gel vehicle at2.5% weight/weight containing polymeric nanocapsules, especially the cationic nanocapsules, demonstrated ­applicability for the vaginal delivery of hydrophobic substances.Keywords: Eudragit® RS100, Eudragit® S100, vaginal route, nanotechnology

Exposure to solar radiation, particularly its ultraviolet (UV) component, has a variety of harmful effects on human health. Some of these effects include sunburn cell formations, basal and squamous cell cancers, melanoma, cataracts, photoaging of the skin, and immune suppression. The beneficial photoprotective effects of topical formulations with the extract,Morinda citrifolia, have not been investigated. This present study aims to investigate the potential benefits ofM. citrifoliatopical application on the dorsal skin of mice, exposed to UVA-UVB light. Using 7 days of treatment, [before (baseline values) and 20 h after UV exposure], the thickness, skin barrier damage (TEWL), erythema, and histological alterations were evaluated. The results showed that the formulations containing the extract protected the skin against UV-induced damage.

Rice bran oil (RBO) is obtained from bran, a by-product of the rice bran milling process. Scientific interest in RBO oil is recent compared to major edible vegetable oils. It presents several phytochemical compounds with beneficial therapeutic effects, such as antioxidant, anti-inflammatory, and hypoglycemic. γ-Oryzanol is a potent antioxidant component present only in rice bran oil. In recent years, research has focused on the development of new pharmaceutical dosage forms, cosmetic formulations, or food products containing biological compounds obtained from rice bran oil to improve the treatment of diseases and human health. In this scenario, this chapter covers relevant aspects of RBO, including source and composition, beneficial effects on treating several diseases, and applications in the development of pharmaceutical or cosmetic formulations.

In spite of different methods reported in the literature to determine olanzapine in biological fluids, all of them used high volumes of plasma. Therefore, the purpose of this paper was to develop an LC-MS/MS method using small plasma volume (0.1 mL) to apply in a preclinical pharmacokinetic investigation. The method was linear over the concentration ranges of 10 - 1000 ng mL-1. Extraction recoveries, stability, and validation parameters were evaluated. Results were within the acceptable limits of international guidelines. A significant decrease in clearance led to a significant 2.26-times increase in AUC0 - 6h of olanzapine-loaded lipid-core nanocapsules compared with free-olanzapine.

The aim of this work was to determine whether encapsulation of a non steroidal antiinflammatory agent within nanocapsules could reduce local toxicity after intramuscular injection. Diclofenac-loaded nanocapsules were prepared by deposition of poly(rac-lactic acid) polymer, and administered intramuscularly to male Wistar rats. Plasma creatine phosphokinase (CPK) activity and histological examination were used to assess local tissue damage. Following a single intramuscular injection of diclofenac (0.8 mg), CPK activity was shown to depend on both the type of dosage form and, in the case of nanocapsules, on the chemical nature of the central oily core. Lower CPK activity was observed with nanocapsules prepared from Miglyol 810, a caprylic/capric triglyceride, while nanocapsules prepared from benzyl benzoate, either empty or containing diclofenac, exhibited the same CPK activity as the drug solution. Histopathological examination performed three days after administration of free diclofenac or nanocapsules containing diclofenac prepared from Miglyol 810 revealed that a much more intense inflammation was obtained with the solution than with nanocapsules. In conclusion, when appropriately formulated, nanocapsules can considerably reduce the muscular damage caused by diclofenac.

PURPOSE: To evaluate the effects of lipoic acid (thioctic acid) topical application on wound healing on rats skin, and the consequences of lipoic acid nanoencapsulation on this process. METHODS: The model used was the healing activity on wounds induced by surgical incision on rats skin (n = 44). The parameters analyzed (11 days) were wound healing rate and histology (vascular proliferation, polymorphonuclear or mononuclear cells, and collagen synthesis or reepithelialization), after application of free lipoic acid or lipoic acid- loaded nanocapsules. The antioxidant activity of these formulations was evaluated by lipid peroxidation test. RESULTS: It was demonstrated for the first time that the topical application of lipoic acid improves wound healing. On the seventh day after surgery, the animals treated with lipoic acid showed increased healing rate (60.7 ± 8.4%) compared to the negative control group (43.0 ± 17.4%), as so improvement of histological parameters. The nanoencapsulation reverted the pro-oxidant activity presented in vitro by lipoic acid, whereas diminished wound repair. CONCLUSIONS: The topical application of lipoic acid produced an increase in the skin wound healing, which may be related to its pro-oxidant activity. On the other hand, the nanoencapsulation of the lipoic acid reversed the pro-oxidant activity, although presented minor healing activity.

The aim of this study was to develop innovative nanosystems with isopropyl myristate as the oil core of self-assembly nanovesicles constituted of chitosan and lecithin using a 2(3) factorial design. The factors analyzed were chitosan (X1, levels 4 and 8 mg/ml), oil (X2, levels 10 and 20 mg/ml) and lecithin (X3, levels 4 and 8 mg/ml). The responses evaluated were diameter, zeta potential, pH, viscosity, and backscattering analysis. The bioavailability was evaluated after oral administration of clozapine free and nanoencapsulated in rats. The diameter ranged from 0.348 to 1.5 µm for F2 (X1, 4; X2, 10; X3, 8 mg/ml) and F7 (X1, 8; X2, 20; X3, 4 mg/ml), respectively. Laser diffractometry analysis revealed only one diameter population for all batches. Zeta potential was positive, being influenced by X1 and X2/X3 association. Viscosity values were dependent on the X1 and X2 concentrations used. A structure proposed for the nanosystem consists of chitosan forming the hydrophilic shell layer that protects the core comprised of lecithin and the hydrophobic groups of oil. The AUC0-∞ was almost 3 times higher with the clozapine nanoencapsuted in relation to free drug. It was developed a new nanosystem which is able of improving the absorption of drugs.

INTRODUCTION The cosmetic benefit obtained from the use of lipoic acid in the treatment of different skin disorders related to oxidative stress is compromised by its chemical instability, which complicates the preparation of cosmetic formulations suitable for topical use. Considering that nanoencapsulation increases the stability of lipoic acid, the aim of this study was to develop different semisolid formulations, based on innovative cosmetic ingredients and containing lipoic acid-loaded nanocapsules. MATERIALS AND METHODS Lipoic acid-loaded nanocapsules (5.0 mg/mL) were prepared by interfacial deposition of the pre-formed polymer and the thickening agents Aristoflex AVC and DC RM2051, used alone or in combination. The formulations were characterized in terms of resistance to centrifugation, pH, lipoic acid content, rheological characteristics and optical parameters determined by multiple light scattering. Also, their stability when subjected to cycles of thermal heating and freezing was evaluated. RESULTS AND DISCUSSION The semisolid formulations presented suitable properties for cutaneous administration, with enhanced physicochemical stability, considering the drug content and resistance to centrifugation, being observed for the formulations containing nanocapsules. All of the proposed formulations showed pseudoplastic flow behavior. The nanoencapsulation leads to an increase in the flow indexes. After the stress cycles an improvement in the consistency, particularly for the formulations containing nanocapsules, was observed. According to the results of multiple light scattering analysis, the formulations can be considered stable. CONCLUSIONS The use of new cosmetic ingredients, unlike traditional hydrogels, represents a differentiated platform for preparation of stable semisolid formulations containing polymeric nanocapsules, presenting physicochemical properties suitable for topical use.

Andressa Bernardi,1,* Rudimar L Frozza,2,* Juliana B Hoppe,2 Christianne Salbego,2 Adriana R Pohlmann,1,3 Ana Maria O Battastini,2 Sílvia S Guterres11Programa de Pós-Graduação em Ciências Farmacêuticas, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brasil; 2Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, UFRGS, Porto Alegre, RS, Brasil; 3Departamento de Química Orgânica, Instituto de Química, UFRGS, Porto Alegre, RS, Brasil *Both authors contributed equally to this workAbstract: Despite recent advances in radiotherapy, chemotherapy, and surgical techniques, glioblastoma multiforme (GBM) prognosis remains dismal. There is an urgent need for new therapeutic strategies. Nanoparticles of biodegradable polymers for anticancer drug delivery have attracted intense interest in recent years because they can provide sustained, controlled, and targeted delivery. Here, we investigate the mechanisms involved in the antiproliferative effect of indomethacin-loaded lipid-core nanocapsules (IndOH-LNC) in glioma cells. IndOH-LNC were able to reduce cell viability by inducing apoptotic cell death in C6 and U138-MG glioma cell lines. Interestingly, IndOH-LNC did not affect the viability of primary astrocytes, suggesting that this formulation selectively targeted transformed cells. Mechanistically, IndOH-LNC induced inhibition of cell growth and cell-cycle arrest to be correlated with the inactivation of AKT and ß-catenin and the activation of GSK-3ß. IndOH-LNC also induced G0/G1 and/or G2/M phase arrest, which was accompanied by a decrease in the levels of cyclin D1, cyclin B1, pRb, and pcdc2 and an increase in the levels of Wee1 CDK inhibitor p21WAF1. Additionally, IndOH-LNC promoted GBM cell differentiation, observed as upregulation of glial fibrillary acidic protein (GFAP) protein and downregulation of nestin and CD133. Taken together, the crosstalk among antiproliferative effects, cell-cycle arrest, apoptosis, and cell differentiation should be considered when tailoring pharmacological interventions aimed at reducing glioma growth by using formulations with multiples targets, such as IndOH-LNC.Keywords: glioblastoma multiforme, PI3K/AKT, cell differentiation, indomethacin-loaded lipid core nanocapsules, cell cycle regulation

In nanomedicine, different nanomaterials and nanoparticles have been proposed as therapeutic agents or adjuvants, as well as diagnosis devices. Considering that the principal cause of the ulcerations is the imbalance among the gastric juice secretion and the protection provided by the mucosal barrier and the neutralization of the gastric acid, as well as that nanoparticles are able to accumulate in the gastro-intestinal tissues, we proposed a 2 2 factorial design to evaluate the influence of the chemical composition and the volume fraction of the dispersed phase on the gastric protective effect against ulceration induced by ethanol. Cocoa-theospheres (CT) and lipid-core nanocapsules (LNC) (two different kinds of surfaces: lipid and polymeric, respectively) prepared at two different concentrations of soft materials: 4% and 12% (w/v) were produced by high pressure homogenization and solvent displacement methods, respectively. Laser diffraction showed volume-weighted mean diameters ranging from 133 to 207 nm, number median diameters lower than 100 nm and specific surfaces between 41.2 and 51.2 m 2 g -1 . The formulations had pH ranging from 4.7 to 6.3; and zeta potential close to -9 mV due to their coating with polysorbate 80. The ulcer indexes were 0.40 (LNC 4 ) and 0.48 (CT 4 ) for the lower total administered areas (3.3 and 4.1 msup>2 g -1 , respectively), and 0.09 (LNC 12 and CT 12 ) for the higher administered areas (10.0 and 12.0 m 2 g -1 , respectively). LNC 4 , LNC 12 and CT 12 showed lower levels in the lipid peroxidation assay when compared either to the negative control (saline) or to CT 4 . LNC 12 and CT 12 showed similar TBARS levels, as well as CT 4 was similar to the negative control. SEM analysis of the stomach mucosa showed coatings more homogenous and cohesive when LNC formulations were administered compared to the correspondent CT formulations. The higher total area of administered nanoparticles showed film formation. Moreover, LNC 12 provided a more thick and cohesive film, completely covering the mucosal surface. In conclusion, both kinds of formulations are able to prevent ulceration induced by ethanol in rats. The 2 2 factorial design showed that the chemical composition had a strong influence when the lower areas of nanoparticles are administered, while when the higher areas are used this is the more influencing parameter on the gastroprotection.

The aim of this work was to formulate nanocapsules prepared from poly(DL-lactide) containing a non-steroidal anti-infammatory drug, diclofenac, and to study their stability during storage at room temperature. The influence of some factors wich could affect stability, namely, the type of oily phase used or/and its concentration, the concentrations of drug and of surfactants, was investigated. The pH of the preparation, the particle size, the quantity of drug remaining (encapsulated and total) and polymer molecular weight were determined at intervals for up to 8 months after nanocapsule preparation. Although colloidal systems which were physically stable over this period could be obtained with either of the two oils tested, polymer degradation was more rapid in the presence of benzyl benzoate than with Miglyol 810®. The optimal concentration of the latter was found to be 3.33%. The highest loading of diclofenac consistent with a stable preparation was 1.00 mg/ml. Stable nanocapsules could be obtained with as little as 0.75% lipophilic surfactant together with a similar concentration of hydrophilic surfactant. These concentrations are considerably lower than those described in the literature for the formulation of this type of colloid.

Polymeric nanocarriers have shown great promise as delivery systems. An alternative strategy has been to explore new delivery routes, such as intradermal (i.d.), that can be used for vaccines and patch-based drug delivery. Despite their many advantages, there are few toxicity studies, especially in vivo. We report a safety assessment of biodegradable poly(ɛ-caprolactone) lipid-core nanocapsules (LNC) with a mean size of 245±10nm following single and repeated intradermal injections to Wistar rats. Suspensions were prepared by interfacial deposition of polymer. The animals (n=6/group) received a single-dose of saline solution (1.2ml/kg) or LNC (7.2×10(12)LNC/kg), or repeated-doses of two controls, saline solution or Tween 80 (0.9ml/kg), or three different concentrations of LNC (1.8, 3.6, and 5.4×10(12)LNC/kg) for 28 consecutive days. Clinical and physiological signs and mortality were observed. Samples of urine, blood, and tissue were used to perform toxicological evaluation. There were no clinical signs of toxicity or mortality, but there was a slight decrease in the relative body weights in the Tween 80-treated group (p

Synopsis Sensory analysis has become a valuable tool in qualifying consumer perception regarding cosmetic products. This study aims to explore the application of discriminative and affective consumers sensory analysis in evaluating the influence of nanoencapsulation on the sensory properties and rheological characteristics of a cosmetic formulation containing lipoic acid. The nanocapsules were prepared by the pre-formed polymer precipitation method. Semisolid formulations were prepared using a silicone emulsion system, and these pseudoplastic fluids were characterized using rheological methods. The panellists (n = 88) analysed the formulations with and without nanoencapsulated lipoic acid as paired comparisons within the discriminative and affective sensory analysis. In these measurements, spreadability, stickiness, oiliness and sulphur odour were evaluated. The panellists had no previous training in conducting these measurements. It was shown that nanotechnology can change some sensory characteristics of the formulations. The spreadability, stickiness and oiliness are the attributes for which the panellists noted differences with statistical significance. The spreadability difference could be due to the results found in the rheological profiles and consistency indexes between formulations. In the discriminative analysis, the panellists could not detect any noticeable differences in the sulphur odour or residual properties between samples, attributes that would influence whether consumers adhered to the selected treatment. Considering affective analysis, the consumers communicated that the formulation containing the nanoencapsulated lipoic acid, which presented less consistency, was preferred based on the reduction in immediate stickiness and residual sulphur odour. The free lipoic acid formulation was preferred in terms of residual oiliness and spreadability.

New Melatonin-loaded vesicular nanocarriers were prepared by interfacial deposition using a blend of an amphiphilic diblock copolymer, poly(methyl methacrylate)-block-poly(2-(dimethylamino)ethyl methacrylate), PMMA-b-PDMAEMA, with poly(epsilon-caprolactone), PCL. Particle size and morphology of the nanocarriers was evaluated. Dynamic light scattering shows that the nanocarriers have hydrodynamic radii between 100 and 180 nm, with unimodal particle size distribution for each formulation. Shape and structure were visualized by transmission electron microscopy (TEM), cryogenic TEM and scanning electron microscopy. Standard TEM for nanocapsules showed an oily core surrounded by a thin layer composed by PCL/PMMA-b-PDMAEMA. Cryo-TEM also indicated the presence of spherical nano-objects with a diffuse polymer corona. Encapsulation efficiencies were determined assaying the nanoparticles by HPLC and higher values of ca. 25% are shown by the nanocapsules. We could successfully incorporate platinum nanoparticles into the nanocarrier as evidenced by TEM, which opens up the possibility for promising applications like monitoring the encapsulated drug in the body.

Chitosomes are chitosan coated liposomes that represent an alternative to conventional liposomes since they present better stability and bioadhesivity. The aim of this work was to develop and evaluate the physico-chemical stability of melatonin (MEL)-loaded chitosomes as well as to compare their properties with that of MEL loaded liposomes. Structural characteristics of nanovesicles were also studied by dynamic light scattering and small angle X-ray scattering. The liposome and chitosome suspensions presented mean diameters between 150 nm and 254 nm, polydispersity indexes around 0.4, zeta potential values between -38 mV and -28 mV, pH values close to 4.0, MEL content close to 100% and encapsulation efficiency between 34.4% and 60.8%. Small angle X-rays scattering showed the presence of unilamelar structures, which were also observed by transmission electronic microscopy. Stability studies focusing on the particle diameter indicated that, within 90 days, the liposome suspensions had a decrease in mean diameter values and in polydispersity indexes, but no alterations were detected in zeta potentials and MEL content. The chitosome suspensions remained stable in relation to these parameters during 90 days. Multiple light scattering analysis (Turbiscan LAb) corroborated the the findings in the stability studies. The result sets pointed out the physico-chemical stability of chitosomes and the chitosan influence in their supramolecular structure.

The hemocompatibility of nanoparticles is of critical importance for their systemic administration as drug delivery systems. Formulations of lipid-core nanocapsules, stabilized with polysorbate 80-lecithin and uncoated or coated with chitosan (LNC and LNC-CS), were prepared and characterized by laser diffraction (D[4,3]: 129 and 134nm), dynamic light scattering (119nm and 133nm), nanoparticle tracking (D50: 124 and 139nm) and particle mobility (zeta potential: −15.1mV and +9.3mV) analysis. In vitro hemocompatibility studies were carried out with mixtures of nanocapsule suspensions in human blood at 2% and 10% (v/v). The prothrombin time showed no significant change independently of the nanocapsule surface potential or its concentration in plasma. Regarding the activated partial thromboplastin time, both suspensions at 2% (v/v) in plasma did not influence the clotting time. Even though suspensions at 10% (v/v) in plasma decreased the clotting times (p

vitro, BQCA increased carbachol potency approx. 90-fold at 10 ÂmM (n 1⁄4 6). In vivo, a maximal brain level of 270 nM was observed 40 min after i.p. administration at 10 mg/kg. Based on in vitro experiments, at level BQCA should produce about 3-fold increase of the agonist potency; it reduced a scopolamine-induced hyper locomotion. Further, BQCA reversed a deficit observed in the two models of memory impairment. Moreover, BQCA showed no side effect at 10 mg/kg and above in spontaneous locomotion as well as in the salivation test. Conclusions: Altogether, these data suggest that theM1 PAMBQCAmay be of interest for the treatment of memory deficits observed in Alzheimer’s disease.

Nanotechnology represents an important complement to traditional chromophore-based UV filters. Nanosized metal oxides are widely used due to their broad protection spectrum and reduced skin irritation. These particles are already present in most commercial sunscreen lotions even though their photoreactivity has been highlighted as a potential cause of cytotoxic effects in human skin cells (e.g. fibroblasts, epithelial cells). However, this cytotoxicity is not likely to represent a significant health risk to consumers as several skin penetration assays have shown that the photoreactive particles penetrate at most to the stratum spinosum of the epidermis. Nanoencapsulation of traditional organic UV filters is a more recent approach to improve skin retention, photostability and the UV blocking ability of the free molecules. All of these improvements have been confirmed with different scientific assays for different particles, especially polymeric nanocapsules and solid lipid nanoparticles. These technological advantages offered by nanometric particles for sun protection formulations have made them commercially important. In inventories from non-governmental organizations there are approximately 30 commercial sunscreen products listed as containing nanoparticles.

Nanotechnology can be used to modify the drug permeation/penetration of encapsulated substances, through the manipulation of many different factors, including direct contact with the skin surface and controlled release. In general, nanoparticles cannot cross the skin barrier, which can be explained by the cell cohesion and lipids of the stratum corneum, the outermost skin layer. The device most commonly used to study the transport of substances and nanoparticles across the skin is the Franz vertical diffusion cell, followed by the substance quantification in the receptor fluid or determination of the amount retained in the skin. Microscopy techniques have also been applied in skin penetration or permeation experiments. This chapter will present the fundamental considerations regarding the transport of encapsulated substances and/or nanoparticles across the skin, the experimental models applied in these studies and a review of the main studies reported in the literature in order to allow the reader to gain insight into the current knowledge available in this area.

This chapter presents an overview of polymeric nanocapsules for dermatological and cosmetic applications, including their preparation methods, physicochemical characterization and models of supramolecular structures. Polymeric nanocapsules are advantageous because of their ability to control the release rate and the penetration/permeation of drugs and active ingredients in the skin. These properties can be modulated through manipulating the qualitative and quantitative compositions of formulations. The chemical nature of raw materials can define the supramolecular structures of the nanocapsule core and surface. In addition, polymeric nanocapsules protect the encapsulated drug or active ingredient from degradation by acting as reservoirs. Aqueous suspensions of polymeric nanocapsules are directly applied on the skin or used as intermediate products for semisolid formulations, such as hydrogels and emulgels. The rheological characteristics of semisolid formulations can be modified by the presence of nanocapsules. Polymeric nanocapsules are valuable devices for skin applications and represent a promising research field in terms of providing products to be explored by industry.

This study describes the validation of a spectrophotometric method to estimate oligonucleotides association with cationic nanoemulsions. Phosphodiester and phosphorothioate oligonucleotides targeting Plasmodium falciparum topoisomerase II were analyzed at 262 nm. Linear response (r > 0.998) was observed from 0.4 to 1.0 nmol/mL, the relative standard deviation values for the intra- and inter-days precision were lower than 2.6% and the recovery ranged from 98.8 to 103.6% for both oligonucleotides. The association efficiency was estimated based on an ultrafiltration/centrifugation method. Oligonucleotides recovery through 30 kDa-membranes was higher than 92%. The extent of oligonucleotides association (42 to 98%) varied with the composition of nanoemulsions.