Protection against oxidative damage in human erythrocytes and preliminary photosafety assessment of Punica granatum seed oil nanoemulsions entrapping polyphenol-rich ethyl acetate fraction

AbstractThe main purpose of the present study is to evaluate the ability of nanoemulsion entrapping pomegranate peel polyphenol-rich ethyl acetate fraction (EAF) prepared from pomegranate seed oil and medium chain triglyceride to protect human erythrocyte membrane from oxidative damage and to assess preliminary in vitro photosafety. In order to evaluate the phototoxic effect of nanoemulsions, human red blood cells (RBCs) are used as a biological model and the rate of haemolysis and photohaemolysis (5Jcm−2 UVA) is assessed in vitro. The level of protection against oxidative damage caused by the peroxyl radical generator AAPH in human RBCs as well as its effects on bilayer membrane characteristics such as fluidity, protein profile and RBCs morphology are determined. EAF-loaded nanoemulsions do not promote haemolysis or photohaemolysis. Anisotropy measurements show that nanoemulsions significantly retrain the increase in membrane fluidity caused by AAPH. SDS-PAGE analysis reveals that AAPH induced degradation of membrane proteins, but that nanoemulsions reduce the extension of degradation. Scanning electron microscopy examinations corroborate the interaction between AAPH, nanoemulsions and the RBC membrane bilayer. Our work demonstrates that Punica granatum nanoemulsions are photosafe and protect RBCs against oxidative damage and possible disturbance of the lipid bilayer of biomembranes. Moreover it suggests that these nanoemulsions could be promising new topical products to reduce the effects of sunlight on skin

Effect of polyethylene glycols addition in microsphere formulations of cellullose acetate butyrate on efficacy carbamazepine and particles morphology encapsulation

O desenvolvimento de microesferas de carbamazepina (CBZ) de liberação prolongada tem sido realizado, empregando-se a técnica de emulsificação/evaporação do solvente e o acetobutirato de celulose (ABC70) para a obtenção da matriz polimérica. Buscando modular a velocidade de liberação do fármaco, a adição de polietilenoglicóis na fase interna da emulsão foi testada. Quando comparados com as microesferas preparadas unicamente com ABC70, o teor e a eficiência de encapsulação da CBZ, estimados após análise por CLAE, foram drasticamente reduzidos com a adição de PEG4000. Entretanto, a adição de PEG 1500 perfazendo 10% da massa total de polímero não pareceu alterar o teor de CBZ, demonstrando que o peso molecular do PEG influencia a encapsulação da CBZ. Partículas mais porosas foram visualizadas por MEV, quando o PEG1500 ou 4000 foram adicionados. Entretanto, a perda da forma esférica foi observada quando uma mistura de ABC70:PEG 4000 1:1 foi empregada. A adição de polietilenoglicóis não pareceu afetar o diâmetro médio das microesferas. A redução na encapsulação da CBZ foi associada à extração do PEG durante a etapa de evaporação do solvente e a sua capacidade de dissolvê-la na fase externa da emulsão. O controle do desenvolvimento da presença de poros, pelo ajuste da concentração e do peso molecular do PEG, pode ser útil na modulação do perfil de liberação do fármaco.With the aim of obtaining carbamazepine (CBZ) prolonged release dosage forms, cellulose acetate butyrate (CAB70) microspheres have been prepared by the emulsion/solvent evaporation method. In order to modulate the CBZ release, the addition of polyethylene glycols (PEG) in the internal phase of the emulsion was carried out. When compared with microspheres prepared only from CAB70, the encapsulation efficiency and the CBZ content were drastically reduced by the PEG 4000 addition. On the other hand, the incorporation of 10% (w/w) of PEG1500 did not affect the drug content in the microspheres. Most porous particles werw observed by SEM when PEG 1500 or 4000 was added to the formulations, however the lost of the spherical shape of the particles was verified when an ABC70:PEG 4000 1:1 mixture was used to prepare the microspheres. The addition of PEGs did not appear to affect the mean diameter of the particles. The decrease of the CBZ content was related to the PEG extraction during the solvent evaporation step and to its ability to dissolve the CBZ in the external phase of the emulsion. The porosity development control, by adjusting the amount or the molecular weight of PEG, can be useful in the drug release from microparticles

Potential use of cellulose acetate butyrate and pluronic F68® blends in the modulation of the diclofenac sodium release from microspheres

Microspheres were prepared using the emulsion/solvent evaporation method with the aim of obtaining diclofenac sodium (DFS) prolonged release dosage forms. The effects of the drug:polymer ratio and addition of Pluronic F68® to the formulations on drug content, particle size and DFS release rate were evaluated using a 22 factorial design. The DFS encapsulation efficiency (%) and the drug content varied from 40 to 70 % and from 4.5 to 13 mg/100 mg, respectively. The mean particle diameter varied from 720 to 850 μm. The addition of Pluronic F68® to the formulations led to an increase in the roughness of the surface. The differential scanning calorimetry (DSC) and infrared spectroscopy (FTIR) studies indicated the presence of Pluronic F68® in the particles. The statistical analysis revealed that the drug content and the release rate of DFS were significantly increased when 1:4 drug:polymer ratio and Pluronic F68® was used to prepare the microspheres.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Photoprotection by Punica granatum seed oil nanoemulsion entrapping polyphenol-rich ethyl acetate fraction against UVB-induced DNA damage in human keratinocyte (HaCaT) cell line

There has been an increase in the use of botanicals as skin photoprotective agents. Pomegranate (Punica granatum L.) is well known for its high concentration of polyphenolic compounds and for its antioxidant and anti-inflammatory properties. The aim of this study was to analyse the photoprotection provided by Punica granatum seed oil nanoemulsion entrapping the polyphenol-rich ethyl acetate fraction against UVB-induced DNA damage in the keratinocyte HaCaT cell line. For this purpose, HaCaT cells were pretreated for 1 h with nanoemulsions in a serum-free medium and then irradiated with UVB (90200 mJ/cm2) rays. Fluorescence microscopy analysis provided information about the cellular internalization of the nanodroplets. We also determined the in vitro SPF of the nanoemulsions and evaluated their phototoxicity using the 3T3 Neutral Red Uptake Phototoxicity Test. The nanoemulsions were able to protect the cells' DNA against UVB-induced damage in a concentration dependent manner. Nanodroplets were internalized by the cells but a higher proportion was detected along the cell membrane. The SPF obtained (~25) depended on the concentration of the ethyl acetate fraction and pomegranate seed oil in the nanoemulsion. The photoprotective formulations were classified as non-phototoxic. In conclusion, nanoemulsions entrapping the polyphenol-rich ethyl acetate fraction show potential for use as a sunscreen product

Curcumin-loaded polymeric and lipid nanocapsules: preparation, characterization and chemical stability evaluation

Polymeric and lipid nanocapsules suspensions of the natural compound curcumin were prepared in order to overcome limitations associated with its clinical applications, such as poor aqueous solubility and susceptibility to hydrolytic and photochemical degradation. Nanocapsule suspensions were prepared by nanoprecipitation and phase inversion methods, respectively. The curcumin formulations were investigated for physicochemical characteristics and in vitro drug release. The hydrolytic and photochemical degradation of the drug associated with the nanocarriers was also determined. For all formulations, the entrapment efficiency values were higher than 99 %. The aqueous colloidal suspensions of curcumin resulted in an increase in drug concentration by a factor of up to 46.103 times. Moreover, stability studies indicated that nanoencapsulation slows down the hydrolytic and photochemical degradations of curcumin. The strategy of nanoencapsulation into polymeric and lipid nanocapsules produced a formulation of curcumin with high drug loading and improved stability, representing a good strategy for the delivery of this drug.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Curcumin-loaded polymeric and lipid nanocapsules: preparation, characterization and chemical stability evaluation

Polymeric and lipid nanocapsules suspensions of the natural compound curcumin were prepared in order to overcome limitations associated with its clinical applications, such as poor aqueous solubility and susceptibility to hydrolytic and photochemical degradation. Nanocapsule suspensions were prepared by nanoprecipitation and phase inversion methods, respectively. The curcumin formulations were investigated for physicochemical characteristics and in vitro drug release. The hydrolytic and photochemical degradation of the drug associated with the nanocarriers was also determined. For all formulations, the entrapment efficiency values were higher than 99 %. The aqueous colloidal suspensions of curcumin resulted in an increase in drug concentration by a factor of up to 46.103 times. Moreover, stability studies indicated that nanoencapsulation slows down the hydrolytic and photochemical degradations of curcumin. The strategy of nanoencapsulation into polymeric and lipid nanocapsules produced a formulation of curcumin with high drug loading and improved stability, representing a good strategy for the delivery of this drug.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Obtenção de extratos secos de carotenoides a partir da biomassa da microalga Haematococcus pluvialis por secagem em torre de aspersão (spray-drying)

Os carotenoides compreendem uma classe de mais de 600 pigmentos naturais, cujo potencial biológicoestá relacionado à sua atividade antioxidante, regulação do crescimento celular, modulação da respostaimune e da atividade anti-inflamatória. A Haematococcus pluvialis é uma microalga verde, conhecida porsintetizar e acumular grandes quantidades de carotenoides, entre estes a astaxantina. Este trabalho tevecomo objetivo preparar e caracterizar extratos secos de H. pluvialis pela técnica de secagem em torre deaspersão, avaliando o efeito do emprego de adjuvantes farmacêuticos e dos parâmetros de secagem sobreas características finais dos extratos secos. Além disso, as atividades antioxidante e citotóxica doscarotenoides obtidos a partir dos extratos secos foram avaliadas. Quando a extração dos carotenoides apartir da biomassa da microalga foi avaliada, altos valores de rendimento que variaram entre 87,8% e94,6% foram obtidos. Após a extração e a secagem por pulverização não foram observadas diferenças namorfologia das partículas e os valores de densidade aparente e compactada não parecem ser afetadosquando as diferentes condições de secagem por pulverização foram testadas. Observou-se que o aumentoda temperatura e concentração do adjuvante de secagem proporcionou redução do teor de carotenoidestotais. Os valores da atividade antioxidante dos extratos de carotenoides variaram entre 55,78 e 77,83%,com os menores valores verificados para os extratos secos preparados com a maior temperatura deentrada. A avaliação da atividade antiproliferativa dos extratos de carotenoides demonstrou que asmaiores concentrações testadas reduziram de 66,58 e 82,91% a viabilidade de células de melanomamurino B16F10. Assim, o conjunto de resultados demonstrou que a obtenção de extratos secos a partir dabiomassa de Haematococcus pluvialis visando a produção de matérias-primas farmacêuticas utilizando asecagem em torre de aspersão (spray dryer) é promissor especialmente, com altos valores de carotenoidestotais e sem perda significativa da atividade antioxidante.Palavras-chave: carotenoides, microalgas, secagem por pulverização, astaxantina, antioxidantes

Protection against Oxidative Damage in Human Erythrocytes and Preliminary Photosafety Assessment of Punica granatum Seed Oil Nanoemulsions Entrapping Polyphenol-rich Ethyl Acetate Fraction

The main purpose of the present study is to evaluate the ability of nanoemulsion entrapping pomegranate peel polyphenol-rich ethyl acetate fraction (EAF) prepared from pomegranate seed oil and medium chain triglyceride to protect human erythrocyte membrane from oxidative damage and to assess preliminary in vitro photosafety. In order to evaluate the phototoxic effect of nanoemulsions, human red blood cells (RBCs) are used as a biological model and the rate of haemolysis and photohaemolysis (5 J cm-2 UVA) is assessed in vitro. The level of protection against oxidative damage caused by the peroxyl radical generator AAPH in human RBCs as well as its effects on bilayer membrane characteristics such as fluidity, protein profile and RBCs morphology are determined. EAF-loaded nanoemulsions do not promote haemolysis or photohaemolysis. Anisotropy measurements show that nanoemulsions significantly retrain the increase in membrane fluidity caused by AAPH. SDS-PAGE analysis reveal that AAPH induced degradation of membrane proteins, but that nanoemulsions reduce the extend of degradation. Scanning electron microscopy examinations corroborate the interaction between AAPH, nanoemulsions and the RBCs membrane bilayer. Our work demonstrates that P. granatum nanoemulsions are photosafe and protect RBCs against oxidative damage and possible disturbance of the lipid bilayer of biomembranes. Moreover it suggests that these nanoemulsions could be promising new topical products to reduce the effects of sunlight on ski

Curcumin-loaded polymeric and lipid nanocapsules: preparation, characterization and chemical stability evaluation

Polymeric and lipid nanocapsules suspensions of the natural compound curcumin were prepared in order to overcome limitations associated with its clinical applications, such as poor aqueous solubility and susceptibility to hydrolytic and photochemical degradation. Nanocapsule suspensions were prepared by nanoprecipitation and phase inversion methods, respectively. The curcumin formulations were investigated for physicochemical characteristics and in vitro drug release. The hydrolytic and photochemical degradation of the drug associated with the nanocarriers was also determined. For all formulations, the entrapment efficiency values were higher than 99 %. The aqueous colloidal suspensions of curcumin resulted in an increase in drug concentration by a factor of up to 46.103 times. Moreover, stability studies indicated that nanoencapsulation slows down the hydrolytic and photochemical degradations of curcumin. The strategy of nanoencapsulation into polymeric and lipid nanocapsules produced a formulation of curcumin with high drug loading and improved stability, representing a good strategy for the delivery of this drug.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Formulation study of quercetin-loaded lipid-based nanocarriers obtained by hot solvent diffusion method

Lipid-based nanocarriers were prepared by hot solvent diffusion technique. Tristearin (TS) and/or castor oil were employed as oily phase, and Lutrol F68® or Solutol HS15® and lecithin were employed as surfactant and cosurfactant, respectively. The influence of the formulation variables on surface charge and size of the nanocarriers and their ability to load and control the release of quercetin were investigated. Solid lipid nanoparticles, nanostructured lipid carriers, nanoemulsions, and microemulsions (ME) were obtained depending on the formulation composition. Querecetin (QU) entrapment efficacy was higher than 99 % for all formulations. However, drug content was greatly affected by the formulation composition. ME exhibited the highest capacity to load QU, reaching a concentration around 1,300 times higher than its aqueous solubility. QU release profiles exhibited biphasic kinetics for all formulations. However, the release rate of QU was affected by the properties of the nanocarrier.Colegio de Farmacéuticos de la Provincia de Buenos Aire