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Curcumin is a biopharmaceutical classification system (BCS) class IV substance with many potential therapeutic effects. However, like many other BCS IV active pharmaceutical ingredients, complex formulations are needed to guarantee a sufficiently high bioavailability. A not-so-well-known delivery system is a suspoemulsion (SE). SEs are emulsions with a crystalline API in continuous or dispersed phases. This study aimed to produce curcumin-loaded o/w suspoemulsions with the particle in the oil phase for, e.g., encapsulation or triggered release effects. The particles need to be smaller than the emulsion droplet size to attain high encapsulation efficiencies (EE) in the oil phase. Sonofragmentation and bead milling were tested for their ability to produce these nanocrystals in different dispersion media. It was discovered that production in miglyol was the best fit for the needed application of the crystals in SEs. Around 85% (by volume) of the particles produced with bead milling were smaller than the droplet size of about 5 µm. In contrast, only 23% of the sonofragmentated particles were below the diameter of those droplets. This oily suspension was then used to successfully produce hydrogel-based o/w suspoemulsions. In the second part of this study, we investigated different methods for determining encapsulation efficiency, but none of the methods accurately and satisfactorily resolved the encapsulation efficiency. Finally, the suspoemulsions could not be macroscopically distinguished from one another and were physically stable. In summary, we showed that stable hydrogel-based curcumin-loaded o/w suspoemulsions could be produced. [ABSTRACT FROM AUTHOR]

Many organic sulfur, selenium and tellurium compounds show considerable activity against microorganisms, including bacteria and fungi. This pronounced activity is often due to the specific, oxidizing redox behavior of the chalcogen-chalcogen bond present in such molecules. Interestingly, similar chalcogen-chalcogen motifs are also found in the elemental forms of these elements, and while those materials are insoluble in aqueous media, it has recently been possible to unlock their biological activities using naturally produced or homogenized suspensions of respective chalcogen nanoparticles. Those suspensions can be employed readily and often effectively against common pathogenic microorganisms, still their practical uses are limited as such suspensions are difficult to transport, store and apply. Using mannitol as stabilizer, it is now possible to lyophilize such suspensions to produce solid forms of the nanoparticles, which upon resuspension in water essentially retain their initial size and exhibit considerable biological activity. The sequence of Nanosizing, Lyophilization and Resuspension (NaLyRe) eventually provides access to a range of lyophilized materials which may be considered as easy-to-handle, ready-to-use and at the same time as bioavailable, active forms of otherwise insoluble or sparingly substances. In the case of elemental sulfur, selenium and tellurium, this approach promises wider practical applications, for instance in the medical or agricultural arena. [ABSTRACT FROM AUTHOR]