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In recent years, integrated data analysis has proven to be a valuable method for investigating complex systems, whether artificial or natural. The integrated analytical approach allows the simultaneous integration of data acquired from different analytical techniques employed for the same sample at the same time, leading to an expansion of the amount of information available. Surface tensiometry is a technique that was recently introduced in the Integrated Analytical Approach for investigating pharmaceutical dosage forms for topical application. Therefore, studies of rheological characterization, release, and skin permeation can be integrated with surface tensiometry measurements to develop chemical and rheological-surface correlation models, providing a new method for the quality control and process control of semisolid preparations. In this context, the aim of this research is to validate the utility of surface tensiometry measurements in the Integrated Analytical Approach and utilize these data to gain insights into the structure-surface correlation. The preparations chosen for this study were a PEG-gel, a lipogel, and an O/W cream containing carnitine as a model drug. The formulations were characterized using rheological measurements and evaluated for their carnitine release performance. Furthermore, surface tensiometry measurements were performed to rapidly and noninvasively assess the influence of carnitine on the surface properties of the semisolid preparations investigated. Our work demonstrated a close correlation between surface energy and structural data, showing the importance of surface tensiometry contribution in the noninvasive and rapid evaluation of the presence of carnitine in semisolid formulations.

The diffusion coefficient (also known as diffusivity) of an active pharmaceutical ingredient (API) is a fundamental physicochemical parameter that affects passive diffusion through biological barriers and, as a consequence, bioavailability and biodistribution. However, this parameter is often neglected, and it is quite difficult to find diffusion coefficients of small molecules of pharmaceutical relevance in the literature. The available methods to measure diffusion coefficients of drugs all suffer from limitations that range from poor sensitivity to high selectivity of the measurements or the need for dedicated instrumentation. In this work, a simple but reliable method based on time-resolved concentration measurements by UV-visible spectroscopy in an unstirred aqueous environment was developed. This method is based on spectroscopic measurement of the variation of the local concentration of a substance during spontaneous migration of molecules, followed by standard mathematical treatment of the data in order to solve Fick's law of diffusion. This method is extremely sensitive and results in highly reproducible data. The technique was also employed to verify the influence of the environmental characteristics (i.e., ionic strength and presence of complexing agents) on the diffusivity. The method can be employed in any research laboratory equipped with a standard UV-visible spectrophotometer and could become a useful and straightforward tool in order to characterize diffusion coefficients in physiological conditions and help to better understand the drug permeability process.

This study describes the formulation optimization and body-cell distribution and clearance in mice of a dually fluorescent biodegradable poly avidin nanoassembly based on the novel Avidin-Nucleic-Acid-Nano-ASsembly (ANANAS) platform as a potential advancement of classic avidin/biotin-based targeted delivery. The nanoformulation circulates freely in the bloodstream; it is slowly captured by filter organs; it is efficiently cleared within 24-48 h, and it is poorly immunogenic. The system displays more favorable properties than its parent monomeric avidin and it is a promising tool for diagnostic purposes for future translational aims, for which free circulation in the bloodstream, safety, multifunctionality and high composition definition are all necessary requirements. In addition, the assembly shows a time-dependent cell penetration capability, suggesting it may also function as a NP-dependent drug delivery tool. The ease of preparation together with the possibility to fine-tune the surface composition makes it also an ideal candidate to understand if and how nanoparticle composition affects its localization.