The development and evaluation of a hydrogel drug delivery system for dithranol.

Dithranol is widely used in the treatment of psoriasis, but it has the drawbacks of instability, staining of skin and clothes, and irritation, especially of non-involved skin. A polyurethaneurea hydrogel in sheet form has been used to investigate the possibility of developing a drug delivery system that would confine dithranol to the psoriatic plaque, whilst also providing appropriate stability and drug delivery rates. Analytical methods were developed and evaluated, to ensure that dithranol stability could be monitored and release rates measured. A high-performance liquid chromatography (HPLC) method enabled the assay of dithranol, danthrone and dimer at concentrations appropriate for stability studies and longer-time release experiments. A more sensitive fluorimetric method enabled assay of the dithranol in the low concentrations occurring in the early stages of release experiments. Hydrogels were loaded using a dithranol solution. The blend of solvents for the loading solution were selected to optimize dithranol solubility and hydrogel swelling, and to minimise oxidation of dithranol. Storage conditions for the loading films were also optimized until a zero order half-life of 30 days for the loaded film was obtained. In vitro release studies indicated that the process was slower and less extensive into aqueous media than into non-aqueous media. Stratum corneum, however, acts as a rate-limiting membrane so that the release rate became independent of receptor medium hydrophobicity. A rate constant of dithranol release from hydrogel through stratum corneum of 0.2 μg/cm2/hr was obtained. The hydrogel was evaluated on 5 normal and 8 psoriatic patients. Clinical response was measured by scoring scaliness, thickness, erythema and staining. Detailed time course evaluation on two psoriatic patients indicated that there was a lag time of 7 hours after application before the first clinical response was obtained. Comparative studies on 5 normal volunteers indicated that there was an approximate bioequivalence between the hydrogel and 0.1% Dithrocream. This was confirmed with 6 psoriatic patients which also showed that both are more effective than occlusion alone or blank hydrogel. From the data obtained, some suggestions about the possible effective concentration - and the site and mechanism - of action of dithranol in psoriasis are discussed

Efficacy and safety of two artificial saliva-based polymers containing 0.1% pilocarpine for treatment of xerostomia : a randomized clinical pilot trial

Topical agents are the mainstay in the treatment of xerostomia, a common complaint most frequently associated with salivary dysfunction. This study aimed to compared the efficacy and safety for xerostomia treatment of 2 artificial saliva preparations containing 0.1% pilocarpine, and, either sodium carboxymethylcellulose (SCMC), or, sodium polyacrylate (SPA)

Black liquor disposal by vortex incineration: A computational approach.

The important role of black liquor in the pulp and paper industry has, been addressed and a review of conventional and potential alternative technologies has been made. Black liquor combustion properties and its combustion within a conventional recovery boiler, the principle of vortex combustion, and methods of computational fluid dynamics were summarized. In order to use the commercially available computational fluid dynamics package, PHOENICS, to simulate black liquor combustion in a vortex combustor, the black liquor combustion process was simplified and modelled and additional software programs were developed and attached to the commercial package. The developed module is capable of tracking trajectory paths of black liquor particles during combustion. A 250 kW vortex combustor was used for some experimental work. The combustor was first tested with natural gas and kerosene. The - combustion conditions were satisfied and their characteristics were presented. Atomization was the main technical problem in the combustion of black liquor. However, the environmental problem was also severe. The results were presented and discussed. Improvements of the system and further studied were suggested. Selection of a suitable turbulence model was made by comparing experimental data with the simulations from various turbulence models. Prandtl mixing length model gave closer predictions than k-? and k-1 model and therefore, it was used for the entire simulations. Simulations of natural gas combustion in a vortex combustor were made to establish skill and confidence in using the package, PHOENICS, to deal with combustion process. A series of black liquor combustion models were performed afterward using the particle tracking module developed. This led to the suggestion of a potential suitable geometry of a vortex combustor for black liquor incineration. The results were presented and discussed. Further simulation studies are also suggested

Black liquor disposal by vortex incineration: A computational approach.

The important role of black liquor in the pulp and paper industry has, been addressed and a review of conventional and potential alternative technologies has been made. Black liquor combustion properties and its combustion within a conventional recovery boiler, the principle of vortex combustion, and methods of computational fluid dynamics were summarized. In order to use the commercially available computational fluid dynamics package, PHOENICS, to simulate black liquor combustion in a vortex combustor, the black liquor combustion process was simplified and modelled and additional software programs were developed and attached to the commercial package. The developed module is capable of tracking trajectory paths of black liquor particles during combustion. A 250 kW vortex combustor was used for some experimental work. The combustor was first tested with natural gas and kerosene. The - combustion conditions were satisfied and their characteristics were presented. Atomization was the main technical problem in the combustion of black liquor. However, the environmental problem was also severe. The results were presented and discussed. Improvements of the system and further studied were suggested. Selection of a suitable turbulence model was made by comparing experimental data with the simulations from various turbulence models. Prandtl mixing length model gave closer predictions than k-? and k-1 model and therefore, it was used for the entire simulations. Simulations of natural gas combustion in a vortex combustor were made to establish skill and confidence in using the package, PHOENICS, to deal with combustion process. A series of black liquor combustion models were performed afterward using the particle tracking module developed. This led to the suggestion of a potential suitable geometry of a vortex combustor for black liquor incineration. The results were presented and discussed. Further simulation studies are also suggested

Eucalyptus ash alters secondary protein conformation of human grey hair and facilitates anthocyanin dyeing

<div><p>Wood ashes infused with water have been traditionally used as hair cosmetics, but little or no research has examined the effects of ash on human hair. This study investigated the effect of eucalyptus ash on the structure and morphology of excised human grey hair and its potential use as a pretreatment in natural hair dyeing using anthocyanins extracted from purple cops of <i>Zea mays</i>. Tensile characteristics and surface morphology of ash-pretreated hair was monitored by texture analysis, scanning electron microscopy and atomic force microscopy. The biochemical characteristics of ash-treated hair were analyzed by synchrotron radiation-FTIR and sulfur <i>K</i>-edge X-ray absorption near edge. Dyeing with anthocyanins was analyzed by Lab color scale and adsorption of anthocyanins. Ash-treated hair was elastically and plastically deformed with microscopic alterations to the ridges of the cuticle cells, similar to ammonia-treated hair. The ash extract significantly changed the relative proportion of alpha-helices in the cuticle and cortex layers (p < 0.05), but did not affect the interaction of S-bonds with neighboring atoms (p > 0.05). Ash-treated hair showed significantly enhanced adsorption of anthocyanins (p < 0.05) which changed the color of the grey hair. The alteration of secondary proteins in the cuticle and cortex layers of the grey hair by ash extract pre-treatment, enhanced anthocyanin adsorption. The eucalyptus ash could potentially be useful as a natural hair dyeing pre-treatment.</p></div

Polymeric Micelles Enhance Mucosal Contact Time and Deposition of Fluocinolone Acetonide

This study used polymeric micelles to improve quality by increasing drug solubility, extending mucosal drug retention time, enhancing mucoadhesiveness, and promoting drug permeation and deposition. Fluocinolone acetonide (FA) was loaded into polymeric micelles (FPM), which were composed of poloxamer 407 (P407), sodium polyacrylate (SPA), and polyethylene glycol 400, and their physicochemical properties were examined. Small-angle X-ray scattering (SAXS) revealed a hexagonal micellar structure at all temperatures, and the concentrations of P407 and SPA were shown to significantly affect the solubility, mucoadhesion, release, and permeation of FPMs. The proportion of P407 to PEG at a ratio of 7.5:15 with or without 0.1% w/v of SPA provided suitable FPM formulations. Moreover, the characteristics of FPMs revealed crystalline states inside the micelles, which was consistent with the morphology and nano-hexagonal structure. The results of ex vivo experiments using focal plane array (FPA)-based Fourier transform infrared (FTIR) imaging showed that the FPM with SPA penetrated quickly through the epithelium, lamina propria, and submucosa, and remained in all layers from 5&ndash;30 min following administration. In contrast, the FPM without SPA penetrated and passed through all layers. The FPM with extended mucoadhesion, improved drug&ndash;mucosal retention time, and increased FA permeation and deposition were successfully developed, and could be a promising innovation for increasing the efficiency of mouth rinses, as well as other topical pharmaceutical and dental applications

Development of a Sericin Hydrogel to Deliver Anthocyanins from Purple Waxy Corn Cob (Zea mays L.) Extract and In Vitro Evaluation of Anti-Inflammatory Effects

Sericin-alginate hydrogel formulations with purple waxy corn (Zea mays L.) cob extract (PWCC) for topical anti-inflammatory application are developed and evaluated. The physical properties such as viscosity, pH, and anthocyanin release are examined and in vitro anti-inflammatory activities, such as NO inhibition and IL-6, IL-1&beta;, TNF-&alpha;, iNOS, and COX-2 expression, are evaluated in LPS-stimulated RAW 264.7 murine macrophages. The sericin-alginate hydrogel is prepared by physical crosslinking through the ionic interaction of the polymers combined with anthocyanin from PWCC at pH 6.5. The hydrogel formulation with 2.00% w/v sericin, 0.20% w/v alginate, and 0.15% w/v PWCC (SN6) shows a suitable viscosity for topical treatment, the highest nitric oxide inhibition (79.43%), no cytotoxicity, and reduced expression of IL-6, IL-1&beta;, and TNF-&alpha; mediators. Moreover, the SN6 formulation displays a sustained anthocyanin release over 8&ndash;12 h, which correlates with the Korsmeyer&ndash;Peppas model. The FT-IR spectrum of SN6 confirmed interaction of the sericin polymer with anthocyanins from PWCC via H-bonding by the shifted peak of amide I and amide III. In addition, the anthocyanin is stable in sericin hydrogels under heating-cooling storage conditions. Therefore, we suggest that this hydrogel formulation has potential as an anti-inflammatory agent. The formulation will be further investigated for in vivo studies and clinical trials in the future