Improving Transungual Permeation Study Design by Increased Bovine Hoof Membrane Thickness and Subsequent Infection

Ungual formulations are regularly tested using human nails or animal surrogates in Franz diffusion cell experiments. Membranes sometimes less than 100 µm thick are used, disregarding the higher physiological thickness of human nails and possible fungal infection. In this study, bovine hoof membranes, healthy or infected with Trichophyton rubrum, underwent different imaging techniques highlighting that continuous pores traversed the entire membrane and infection resulted in fungal growth, both superficial, as well as in the membrane’s matrix. These membrane characteristics resulted in substantial differences in the permeation of the antifungal model substance bifonazole, depending on the dosage forms. Increasing the thickness of healthy membranes from 100 µm to 400 µm disproportionally reduced the permeated amount of bifonazole from the liquid and semisolid forms and allowed for a more pronounced assessment of the effects by excipients, such as urea as the permeation enhancer. Similarly, an infection of 400-µm membranes drastically increased the permeated amount. Therefore, the thickness and infection statuses of the membranes in the permeation experiments were essential for a differential readout, and standardized formulation-dependent experimental setups would be highly beneficial.

Crosslinked Sodium Alginate as a Material for Nanolfiltration Protonic and Aprotonic Solvents

In this work, for the first time, salts of bivalent and trivalent metals were used as crosslinking agents for nanofiltration membranes based on sodium alginate. The developed membranes were investigated for chemical stability in protic and aprotic solvents, the dependence of the permeability of these solvents on their sorption into the membrane material was obtained. The separating properties of membranes based on sodium alginate crosslinked with metal cations were investigated. The retention coefficient of the model substance with a molecular weight of 626 g/mol, dissolved in ethanol, was 97%.

Decomposition of Tars on a Nickel Honeycomb Catalyst

Biomass can be considered a renewable energy source. It undergoes a gasification process to obtain gaseous fuel, which converts it into combustible gaseous products such as hydrogen, carbon monoxide, and methane. The process also generates undesirable tars that can condense in gas lines and cause corrosion, and after processing, can be an additional source of combustible gases. This study focused on the processing of tar substances with toluene as a model substance. The effect of discharge power and carrier gas composition on toluene conversion was tested. The process was conducted in a plasma-catalytic system with a new Ni3Al system in the form of a honeycomb. The toluene conversion reached 90%, and small amounts of ethane, ethylene, acetylene, benzene, and C3 and C4 hydrocarbons were detected in the post-reaction mixture. Changes in the surface composition of the Ni3Al catalyst were observed throughout the experiments. These changes did not affect the toluene conversion.

Assessment of hot-melt coating methods for multiparticulate substrates: Mortar-coating vs. pan-coating

Hot-melt coating (HMC) is an alternative, solvent-free coating method generally used to modify substrate release rate and/or mask its unpleasant taste. The aim of this study was to assess two HMC methods (pan-coating and mortar-coating) by assaying functional properties of the coated material. The selected substrates included highly soluble sodium chloride (model substance) and caffeine (bitter drug), and the coating agent was glycerol distearate without/with the addition of liquid paraffin. Experiments with sodium chloride revealed that pan-coating yielded particles of more regular shape, while mortar-coating yielded samples of more uniform coating layer. The flowability of the coated material depended on the particle size. Sustained sodium chloride release was achieved for all mortar-coated and some pan-coated samples. The analysis of the results indicated mortar-coating as a preferable HMC method for caffeine coating. The resulting caffeine yield in the coated samples was high (99%), the material showed satisfactory mechanical properties and drug release from the coated particles was sustained. Overall, the obtained results suggest that both pan-and mortar-coating can be used to sustain the release of drugs with unpleasant taste, but mortar-coating can be considered as a more simple and practical method that can be potentially used in compounding pharmacies.

Investigation of Anti-fouling and UV-Cleaning Properties of PVDF/TiO2 Mixed-Matrix Membrane for Humic Acid Removal

Natural organic matters (NOMs) have been found to be the major foulant in the application of ultrafiltration (UF) for treating surface water. Against this background, although hydrophilicity has been demonstrated to aid fouling mitigation, other parameters such as membrane surface morphology may contribute equally to improved fouling resistance. In this work, with humic acid solution as the model substance, the effects of titanium dioxides (TiO2) types (PC-20, P25, and X500) on membrane anti-fouling and defouling properties were comparatively analysed. The aims are (1) to determine the correlation between membrane surface morphology and membrane fouling and (2) to investigate the anti-fouling and UV-cleaning abilities of PVDF/TiO2 mixed-matrix membranes with different membrane topographies and surface energy conditions. The mixed-matrix membrane with P25 TiO2 exhibited the most significant UV-defouling ability, with a high irreversible flux recovery ratio (IFRR(UV)) of 16.56 after 6 h of UV irradiation, whereas that with X500 TiO2 exhibited both superior anti-fouling and defouling properties due to its smoother surface and its highly reactive surface layer.

COMPARISONS OF THE HISTOLOGICAL MORPHOLOGY AND IN VITRO PERCUTANEOUS ABSORPTION OF CAFFEINE IN SHED SNAKE SKIN AND HUMAN SKIN

The employment of excised skin (human or animal) mounted in diffusion cells is frequently used for the characterization of biopharmaceutical properties of topical semisolids dosage forms. Reptile skin from snake appears to be a useful alternative to other animal and human skins in assessing the potential for transdermal drug delivery. The aim of the study was to compare human and snake skin from a histological point of view. Furthermore the absorption of caffeine, as a hydrophilic model substance, was compared on snake shed skins (two anatomical locations; ventral and dorsal), from three different species, Python regius, Epicrates maurus colombianus, Lampropeltis triangulum campbelli, and human skin. Snake skin shows histological similarity to human Stratum corneum in term of thickness and composition. Regarding the absorption, the cumulative amount of caffeine increased linearly with time through the dorsal and ventral shed skins of all 3 species. Except for Lampropeltis triangulum campbelli ventral skin, the caffeine permeation behavior obtained on all snake shed skins evaluated was in a similar range as on human skin. One main advantage of shed skin, is that snakes molt regularly and can provide many sheds, that can be obtained without sacrificing the animals.Key words: caffeine; transdermal; shed skin; in vitro; snake; topical formulation PRIMERJAVA HISTOLOŠKE ZGRADBE TER PERKUTANE ABSORPCIJE KOFEINA IN VITRO V LEVKU KAČ IN ČLOVEŠKI KOŽI Povzetek: Koža (človeškega ali živalskega izvora) se pogosto uporablja kot orodje za proučevanje biofarmacevtskih lastnosti topikalnih zdravil. Koža kač bi lahko bila uporabna alternativa drugim živalskim kožam in človeški koži pri oceni sposobnosti prenosa zdravil preko kože. Cilj študije je bil histološka primerjava človeške in kačje kože ter primerjava absorpcije kofeina kot hidrofilne modelne snovi na levkih kač iz dorzalnega in ventralnega področja treh različnih vrst kač: kraljevega pitona (Python regius), mavričnega udava (Epicrates maurus colombianus), mlečne kače (Lampropeltis triangulum campbelli). Kačja koža je histološko podobna človeški glede debeline in sestave roženi plasti (stratum corneum). Glavna prednost levitve kač je, da se dogaja večkrat, kar omogoča pridobitev več levkov, ki se jih lahko pridobi brez žrtvovanja živali. Rezultati so pokazali, da se je skupna količina kofeina sčasoma linearno povečevala v dorzalnih in ventralnih levkih pri vseh treh vrstah kač, razen na na ventralnem področju levka mlečne kače (Lampropeltis triangulum campbelli), pri katerem je bila prehodnost kofeina podobna kot pri prehodu skozi človeško kožo. Ključne besede: kofein; transdermalno; levek; in vitro; kača; topikalni pripravek

Volatile organic compounds (VOCs) control by combining bio-scrubber and ozone pretreatment

<p>Volatile Organic Compounds (VOCs) are toxic for the environment and human health and their tendency to readily volatilize in the atmosphere can lead to problems connected to odours annoyance. Conventional VOCs gaseous emissions treatments entail the application of chemical-physical processes, only promoting the transfer of the contaminants from gas to liquid and/or solid phases. Advanced Oxidation Process (AOPs) and biological processes, conversely, support the oxidation of the organic pollutants, promoting their conversion into harmless and odourless compounds. The integration of booth processes is suggested to increase treatability of VOC. The research presents the application of an innovative treatment system composed by an AOPs pretreatment coupled with a bio-scrubbing unit for the abatement of VOCs, with the aim to increase the removal efficiency. The evaluation of the performance of the proposed system is discussed with reference to the analysis carried out using toluene as model substance. Different operating conditions have been analyzed and investigated to optimize the removal efficiency. The results show that the ozonation applied as pretreatment to the biological process may promote an increase of the pollutant biodegradability along with synergic effects due to the absorption of the ozone derived compounds into the culture growth, resulting in a significant enhancement of removal performances respect to the conventional biotechnologies. A toluene removal efficiency up to 95% were obtained under the investigated conditions.</p>

Development and Study of Semi-Solid Preparations Containing the Model Substance Corticotropin (ACTH): Convenience Application in Neurodegenerative Diseases

Corticotropin (ACTH, previously an adrenocorticotropic hormone) is used in the diagnosis and treatment of pituitary gland disorders, adrenal cortex disorders, and other diseases, including autoimmune polymyositis, systemic lupus erythematosus, rheumatoid arthritis, Crohn’s disease, and ulcerative colitis. So far, the ointment dosage form containing ACTH for use on the skin is unknown. Therefore, it seems appropriate to develop a semi-solid formulation with corticotropin. Emulsion ointments were prepared using an Unguator based on the cream base Lekobaza® containing corticotropin in different concentrations, and then the physical and chemical parameters of the ointment formulations, such as pH, spreadability, rheological properties, and texture analysis, were evaluated. In addition, a USP apparatus 2 with enhancer cells was utilized to study the in vitro drug release characteristics of the selected formulations. All the ointments obtained were characterized by good spreadability and viscosity. An analysis of the ointment texture was performed and the dependence of the tested parameters on the ACTH content in the ointment was demonstrated. Examination of the structure of the ointment showed that a high concentration of ACTH increases the hardness and adhesiveness of the ointment. In turn, it adversely affects the cohesiveness and elasticity of the ointments tested. The results of the release study showed that ACTH is released the fastest from the formulation with the lowest concentration, while the slowest from the ointment with the highest concentration of ACTH.