Ex-vivo complexation, skin permeation, interaction and cytodermal toxicity studies of p-tertbutylcalix[4]arene nanoemulsion for radiation decontamination

A Simple, Rapid, Comparative Evaluation of Multiple Products for Decontamination of Actinide-contaminated Rat Skin Ex Vivo

ABSTRACT

Decontamination of skin is an important medical countermeasure in order to limit potential internal contamination by radionuclides such as actinides. Minimizing skin surface contamination will ultimately prevent internal contamination and subsequent committed effective dose as well as contamination spreading. The decontamination agents tested on a rat skin ex vivo model ranged from water to hydrogel wound dressings. A surfactant-containing cleansing gel and calixarene nanoemulsion with chelation properties demonstrated marked decontamination efficacies as compared with water or the chelator DTPA. Based on efficacy to remove different actinide physicochemical forms from skin, the results demonstrate that all products can remove the more soluble forms, but a further component of emulsifying or tensioactive action is required for less soluble forms. This indicates that for practical purposes, successful decontamination will depend on identification of the actinide element, the physicochemical form, and possibly the solvent. This study offers a simple, quick, cheap, reproducible screening method for efficacy evaluation of multiple products for removal of a variety of contaminants.

Oleuropein as a novel topical antipsoriatic nutraceutical: formulation in microemulsion nanocarrier and exploratory clinical appraisal

Introduction: Oleuropein is a promising nutraceutical found in abundance in olive leaf, with reported antioxidant and anti-inflammatory properties, and hence could be a valuable treatment for dermatological diseases such as psoriasis.Areas covered: In order to overcome the poor skin penetration of oleuropein, it was formulated in a microemulsion nanocarrier. The selected microemulsion formulation displayed a particle size of 30.25 ± 4.8 nm, zeta potential 0.15 ± 0.08 mV and polydispersity index 0.3 ± 0.08, with storage stability for 1 year in room temperature and total deposition in skin layers amounting to 95.67%. Upon clinical examination in psoriatic patients, the oleuropein microemulsion formulation was proven superior to the marketed Dermovate cream composed of clobetasol propionate, in terms of reduction of Psoriasis Area and Severity Index (PASI) scores, as well dermoscopic imaging and morphometric analysis of the psoriasis lesions, in which oleuropein microemulsion exhibited marked improvement in the clinical manifestations of psoriasis.Expert opinion: The findings of this study further prove the promising role of nutraceuticals, as well as nanoparticles in enhancing the therapeutic outcome of treatments, and open new era of applications in a variety of diseases.

Skin decontamination procedures against potential hazards substances exposure

Decontamination of unprotected skin areas is crucial to prevent excessive penetration of chemical contaminants after criminal or accidental release. A review of literature studies was performed to identify the available decontamination methods adopted to treat skin contamination after chemical, radiological and metal exposures. In this bibliographic review, an overview of the old and recent works on decontamination procedures followed in case of potential hazards substances contaminations with a comparison between these systems are provided. Almost all data from our 95 selected studies conducted in vitro and in vivo revealed that a rapid skin decontamination process is the most efficient way to reduce the risk of intoxication. The commonly-used or recommended conventional procedures are simple rinsing with water only or soapy water. However, this approach has some limitations because an easy removal by flushing may not be sufficient to decontaminate all chemical deposited on the skin, and skin absorption can be enhanced by the wash-in effect. Other liquid solutions or systems as adsorbent powders, mobilizing agents, chelation therapy are also applied as decontaminants, but till nowadays does not exist a decontamination method which can be adopted in all situations. Therefore, there is an urgent need to develop more efficient and successful decontaminating formulations.

Berberine-Loaded Thiolated Pluronic F127 Polymeric Micelles for Improving Skin Permeation and Retention

Background

Challenges associated with local antibacterial and anti-inflammatory drugs include low penetration and retention of drugs at the expected action site. Additionally, improving these challenges allows for the prevention of side effects that are caused by drug absorption into the systemic circulation and helps to safely treat local skin diseases.

Methods

In the current study, we successfully prepared a thiolated pluronic F127 polymer micelles (BTFM), which binds to keratin through a disulphide bond, to produce skin retention. In addition, the small particle size of polymer micelles promotes the penetration of carriers into the skin. The current study was divided into two experiments: an in vitro experiment; an in vivo experiment that involved the penetration of the micelle-loaded drugs into the skin of rats, the skin irritation test and the anti-inflammatory activity of the drug-loaded micelles on dimethyl benzene-induced ear edema in mice.

Results

Results from our in vitro transdermal experiment revealed that the amount of drug absorbed through the skin was decreased after the drug was loaded in the BTFM. Further, results from the vivo study, which used fluorescence microscopy to identify the location of the BTFM after penetration, revealed that there was strong fluorescence in the epidermis layer, but there was no strong fluorescence in the deep skin layer. In addition, the BTFM had a very good safety profile with no potentially hazardous skin irritation and transdermal administration of BTFM could significantly suppress ear edema induced by dimethyl benzene. Therefore, these findings indicated that BTFM reduced the amount of drug that entered the systemic circulation. Our results also demonstrated that the BTFM had a certain affinity for keratin.

Conclusion

Our experimental results suggest that the BTFM may be an effective drug carrier for local skin therapy with good safety profile.

Synthesis of thiolated arabinoxylan and its application as sustained release mucoadhesive film former

The present work aimed to synthesize thiolated arabinoxylan (TAX), and to evaluate its mucoadhesive potential. Synthesis of TAX was accomplished by esterification of arabinoxylan (AX) with thioglycolic acid (TGA). The appearance of a characteristic peak at 2516 cm^-1 in the FTIR spectrum of TAX, and presence of 6.01 ± 1.03 m moles of thiol per gram of the polymer confirmed successful thiolation of AX. The incorporation of the thiol group considerably promoted mucoadhesive strength of the polymer-viz. 3.99-fold. Moreover, in vivo safety analysis in albino rats revealed TAX to be safe in the concentration range of 750-1000 mg kg^-1 body weight. Synthesized TAX was utilized to prepare Tizanidine HCl (TZN HCl) loaded sustained release (SR) mucoadhesive buccal films using a solvent casting technique. Results proved that the prepared films were of uniform thickness, good mechanical strength (with folding endurance >300), acceptable moisture contents (5%-7%) and surface pH (6.23 ± 0.81 to 6.43 ± 0.49) compatible to that of the buccal cavity. Presence of greater that 90% of drug contents indicated the excellent drug loading ability of the prepared films. Results of in vitro dissolution studies and ex vivo permeation studies conducted respectively by USP dissolution apparatus II and Franz diffusion cell indicated that sustained effect of TAX was achieved for 8 h. These results have conclusively proven that TAX has the potential to improve the bioavailability of TZN HCl due to enhanced mucoadhesion in buccal cavity, hence signifying its suitability as a mucoadhesive buccal film former.