Development of nanoparticles derived from corn as mass producible bionanoparticles with anticancer activity.

Recent studies showed that plant-derived nanoparticles (NPs) can be easily produced in high yields and have potential applications as therapeutic agents or delivery carriers for bioactive molecules. In this study, we selected corn as it is inexpensive to grow and mass-produced globally. Super sweet corn was homogenized in water to obtain corn juice, which was then centrifuged, filtered through a 0.45-µm-pore size syringe filter, and ultracentrifuged to obtain NPs derived from corn, or corn-derived NPs (cNPs). cNPs obtained were approximately 80 nm in diameter and negatively charged (- 17 mV). cNPs were taken up by various types of cells, including colon26 tumor cells and RAW264.7 macrophage-like cells, with selective reduction of the proliferation of colon26 cells. Moreover, cNPs induced tumor necrosis factor-α release from RAW264.7 cells. cNPs and RAW264.7 in combination significantly suppressed the proliferation of colon26/fluc cells. Daily intratumoral injections of cNPs significantly suppressed the growth of subcutaneous colon26 tumors in mice, with no significant body weight loss. These results indicate excellent anti-tumor activity of cNPs.

Prediction of Skin Permeation of Flurbiprofen from Neat Ester Oils and Their O/W Emulsions.

Although many in silico models were reported to predict the skin permeation of drugs from aqueous solutions, few studies were founded on the in silico estimation models for the skin permeation of drugs from neat oil formulations and o/w emulsions. In the present study, the cumulative amount of a model lipophilic drug, flurbiprofen (FP), that permeated through skin was determined from 12 different kinds of ester oils (Qoil) and an in silico model was developed for predicting the skin permeation of FP from these ester oils. Thus, the obtained Qoil values were well predicted with the FP solubility in the oils (Soil), the amount of FP uptake into the stratum corneum (SCoil) and molecular descriptors of dipolarity/polarizability (π2H) and molecular density. This model suggests that the thermodynamic activities of FP both in the formulations and skin are the key factors for predicting the skin permeation of FP from the ester oils. In addition, a high linear relationship was observed in the double-logarithm plots between the Qoil and the cumulative amount of FP permeated through skin from 20% ester oil in water emulsion (Qemul20%). Furthermore, the skin permeations of FP from 5 and 10% ester oil in water emulsions, Qemul5% and Qemul10%, respectively, were also predicted by the horizontal translation of the y-axis intercept of the liner equation for the relation between the Qoil and Qemul20%. These prediction methods must be helpful for designing topical oily and/or o/w emulsion formulations having suitable and high skin permeation rate of lipophilic drugs.

Potential of Stratum Corneum Lipid Liposomes for Screening of Chemical Skin Penetration Enhancers.

The evaluation of effective skin chemical penetration enhancers (CPEs) is a crucial process in the development of transdermal and dermal formulations with the capacity to overcome the stratum corneum barrier. In the present study, we aimed to investigate the potential of stratum corneum lipid liposomes (SCLLs) as an alternative tool for the screening of various types and concentrations of CPEs. SCLLs were prepared using a thin-film hydration technique, and two types of fluorescent probes (sodium fluorescein [FL] or 1,6-diphenyl-1,3,5-hexatriene [DPH] were entrapped separately into SCLLs (FL-SCLL and DPH-SCLL, respectively). FL leakage from SCLLs as well as the fluidity of DPH-SCLLs were determined after incubating with various types of CPEs as a function of their concentrations. The obtained results showed a concentration-dependent relationship for most CPEs both for FL leakage and the fluidity of SCLLs. When observing these data in detail, however, the concentration profiles could be classified into five main categories depending on the mode of action of the CPEs. These results strongly suggest the usefulness of SCLLs for high-throughput screening of effective CPEs as well as the understanding of their possible mode of action, especially in the early stage of skin formulation development.

In Vitro Permeation and Skin Retention of α-Mangostin Proniosome.

The current investigation evaluated the potential of proniosome as a carrier to enhance skin permeation and skin retention of a highly lipophilic compound, α-mangostin. α-Mangostin proniosomes were prepared using the coacervation phase seperation method. Upon hydration, α-mangostin loaded niosomes were characterized for size, polydispersity index (PDI), entrapment efficiency (EE) and ζ-potential. The in vitro permeation experiments with dermis-split Yucatan Micropig (YMP) skin revealed that proniosomes composed of Spans, soya lecithin and cholesterol were able to enhance the skin permeation of α-mangostin with a factor range from 1.8- to 8.0-fold as compared to the control suspension. Furthermore, incorporation of soya lecithin in the proniosomal formulation significantly enhanced the viable epidermis/dermis (VED) concentration of α-mangostin. All the proniosomal formulations (except for S20L) had significantly (p<0.05) enhanced deposition of α-mangostin in the VED layer with a factor range from 2.5- to 2.9-fold as compared to the control suspension. Since addition of Spans and soya lecithin in water improved the solubility of α-mangostin, this would be related to the enhancement of skin permeation and skin concentration of α-mangostin. The choice of non-ionic surfactant in proniosomes is an important factor governing the skin permeation and skin retention of α-mangostin. These results suggested that proniosomes can be utilized as a carrier for highly lipophilic compound like α-mangostin for topical application.

Usefulness of liquid-crystal oral formulations to enhance the bioavailability and skin tissue targeting of p-amino benzoic acid as a model compound.

Topical formulations are not always suitable to deliver active ingredients to large areas of skin. Thus, in this study, we aimed to develop an oral formulation for skin tissue targeting with a high bioavailability using liquid crystal (LC) dispersions comprising cubosomes of a mal-absorptive model compound, p-amino benzoic acid (PABA), which is an active element in cosmeceuticals, dietary supplements and skin disorder medicines. The bioavailability and skin concentration of PABA were investigated after oral administration in rats. The effect of the remaining amount of the LC formulation in the stomach on the pharmacokinetic profiles of orally administered PABA was evaluated. The skin permeation and concentration of PABA were also investigated using an in vitro permeation experiment. As a result, the bioavailability of PABA was significantly improved by administration of PABA-LC formulations compared with PABA solution alone, although the effect was greatly influenced by the type of LC-forming lipids. The in vitro skin permeation study showed that the PABA concentration in the skin when applied from the dermis side was higher than when applied from the epidermis side. These findings suggested that oral administration advantageously supports skin targeting, and oral LC formulations could be a promising material in cosmeceutical, dietary and clinical fields.

Effect of ß-cyclodextrin derivatives on the diosgenin absorption in Caco-2 cell monolayer and rats.

Orally administrated diosgenin, a steroidal saponin found in the roots of Dioscorea villosa, improves reduced skin thickness in ovariectomized mice, and plays an important role in the treatment of hyperlipidemia. Diosgenin has been noticed as an active element in cosmeceutical and dietary supplements. We have already elucidated that the absolute oral bioavailability of diosgenin is very low; however, a high skin distribution of diosgenin was also observed. The aim of the present study was to examine and compare the effects of ß-cyclodextrin (ß-CD) and 3 kinds of its derivatives such as hydroxypropyl ß-CD on the diosgenin permeability using a Caco-2 model and rat jejunal perfusion. These derivatives of ß-CD greatly improved the low solubility of diosgenin. No significant increase was observed in the lactate dehydrogenase leakage from Caco-2 cell, while a slight decrease was found on the transepithelial electrical resistance by diosgenin and ß-CD derivatives. However, ß-CD derivatives, especially hydroxyethyl ß-CD and hydroxypropyl ß-CD, markedly enhanced diosgenin permeability across the Caco-2 monolayer and rat jejunum. The bioavailability of diosgenin in the presence of ß-CD derivatives were about 4 to 11 fold higher than diosgenin suspension. The mechanisms of these enhancement effects may be due to improvements in solubility and tight junction opening.

Pretreatment effects of moxibustion on the skin permeation and skin and muscle concentrations of salicylate in rats.

The effect of moxibustion on the in vitro and in vivo skin permeation of salicylate was evaluated in rats. First, the effect of moxibustion pretreatment on the elimination pharmacokinetics of salicylate after i.v. injection in rats was determined: no clear difference was observed in the plasma profiles of salicylate (SA) with or without moxibustion pretreatment. However, much higher skin and muscle concentrations of salicylate were observed after its i.v. injection. Next, an in vitro skin permeation study of SA was performed after moxibustion pretreatment. Moxibustion pretreatment increased the skin permeation of SA, and the extent of the increase in SA skin permeation was related to the strength of moxibustion ignition. More intense treatments produced higher skin permeation. A similar enhancement effect on the skin permeation of SA was observed in in vivo studies. Interestingly, the skin/plasma and muscle/plasma ratios of SA were markedly increased by moxibustion pretreatment. These results were due to the induction of enhanced skin permeation and lower clearance into the cutaneous vessels by moxibustion ignition. Combination treatment involving moxibustion and the topical application of drugs such as NSAID may be useful for increasing local pharmaceutical effects by enhancing the drug concentration in the skin and muscle underneath the topical application site.

Preparation and evaluation of liquid-crystal formulations with skin-permeation-enhancing abilities for entrapped drugs.

The usefulness of liquid crystals (LC) in topical formulations for application to skin was evaluated by measuring the in vitro permeation profile of a model compound, calcein, entrapped in a LC formulation, through excised hairless rat skin and a three-dimensional cultured human-skin model; the viability was determined using the MTT assay. Two physically stable LCs were prepared from a mixture of mono-, di-, and tri-esters 1, and monoesters 2, composed of erythritol and phytanylacetic acid. Cryo-transmission electron microscopy (cryo-TEM), electron diffraction patterns, and small-angle X-ray diffraction (SAXS) observations of the LC nanodispersions showed that the structures of the LCs were reverse hexagonal (LC-A) and cubic (LC-B). The skin-permeation properties of calcein were enhanced by entrapping in the LCs as a result of the increase in calcein partition from the LC dispersion solution into the skin; the properties were analyzed using a skin-permeation-time profile. Drug partitioning could also be modified by the LC structure. No skin damage was caused by the LC formulation in these experiments.The present study suggests that LC dispersions are potential additives in topical drug formulations and cosmetic formulations.

Pretreatment effects of moxibustion on the skin permeation of FITC-dextran.

This study was conducted to evaluate the pretreatment effects of different in vivo moxibustion on the permeation of a model high molecular compound, FITC-dextran, with a mean molecular weight of 4 kDa (FD-4), through excised hairless rat skin. Direct or indirect moxibustion (0.10 g moxa) was pretreated consecutively 4 times every 5 min on the abdomen of hairless rats, and the permeation of FD-4 was determined through the excised skin over 8h from 30 min after starting the first moxibustion. This consecutive moxibustion pretreatment showed a significant increase in the skin temperature as well as skin permeation of FD-4 compared with the control group (no moxibustion pretreatment). Quantitative parameters showed an increase in skin temperature and skin permeation: the area under the skin temperature over control temperature-time curve during one burning cycle (5.0 min) (AUCtemp) or the maximum skin temperature during moxibustion (Tmax) and the cumulative amount of FD-4 permeated through skin over 8h (Q8) or steady-state flux were increased by moxibustion pretreatment. Then, the effect of pedestal thickness (distance from the moxa cylinder and skin surface), shape of the moxa cylinder (5mm diameter, 13 mm height or 9 mm diameter, 7 mm height), burning materials (moxa or aromatic incense), pedestal component (paper, potato or ginger) and moxibustion pretreatment method (direct or indirect moxibustion) was evaluated on the AUCtemp or Tmax and Q8 or flux. The amount of protein leached from the skin surface was also determined as an inflammatory index by this moxibustion pretreatment. When the skin temperature was increased to 60 degrees C, the Q8 or flux as well as the amount of protein leached were markedly increased. When the skin temperature was controlled to 42 to 45 degrees C by an adequate selection of pedestal thickness, shape of the moxa cylinder, burning materials, pedestal component and moxibustion pretreatment method, on the other hand, protein leaching remained unaltered, but the Q8 or flux significantly increased with the Tmax. This study thus provides credible evidence that moxibustion pretreatment increases the skin permeation of high molecular compounds.

Enhancement of skin permeation of high molecular compounds by a combination of microneedle pretreatment and iontophoresis.

A combination of microneedle pretreatment and iontophoresis was evaluated for the potential to increase skin permeation of drugs. Two model compounds with low and high molecular D(2)O and fluorescein isothiocyanate (FITC)-dextrans (FD-4, FD-10, FD-40, FD-70 and FD-2000; average molecular weight of 3.8, 10.1, 39.0, 71.2 and 200.0 kDa), respectively, were used and the effect of microneedle pretreatment and iontophoresis on their in vitro permeability was evaluated using excised hairless rat skin with a 2-chamber diffusion cell. Convective solvent flow through the skin was measured using a set of calibrated capillaries attached to the diffusion cell. The following results were obtained: (1) convective solvent flow (electroosmosis) during iontophoresis through microneedle-pretreated skin, 2.62+/-0.32 microL/cm(2)/h, was almost the same as through intact skin, 2.71+/-0.25 microL/cm(2)/h, and (2) the combination of microneedle pretreatment and subsequent iontophoresis significantly enhanced FD flux compared with microneedle pretreatment alone or iontophoresis alone, whereas no synergistic effect was found on the flux of D(2)O. These results suggest that the combination of iontophoresis with microneedle pretreatment may be a useful means to increase skin permeation of high molecular compounds.