Microparticles, microspheres, and microcapsules are widely used constituents of multiparticulate drug delivery systems, offering both therapeutic and technological advantages. Microparticles are generally in the 1–1000 µm size range, serve as multiunit drug delivery systems with well-defined physiological and pharmacokinetic benefits in order to improve the effectiveness, tolerability, and patient compliance. This paper reviews their evolution, significance, and formulation factors (excipients and procedures), as well as their most important practical applications (inhaled insulin, liposomal preparations). The article presents the most important structures of microparticles (microspheres, microcapsules, coated pellets, etc.), interpreted with microscopic images too. The most significant production processes (spray drying, extrusion, coacervation, freeze-drying, microfluidics), the drug release mechanisms, and the commonly used excipients, the characterization, and the novel drug delivery systems (microbubbles, microsponges), as well as the preparations used in therapy are discussed in detail.

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Post-translational modifications controlling a large number of biological functions are key aspects of protein diversity. They have an important role controlling cellular processes and may be advantageously utilized. Qualitative and quantitative analyses of post-translational modifications are useful for biomarker research and an integral part of the characterization of protein biopharmaceuticals. Due to its sensitivity and widespread applicability, mass spectrometry has become the core technology of the analysis especially when combined with chromatographic and other separation techniques. The aim of this article is to present a general overview of mass spectrometry applications in the field of PTM mapping. We also present the analytical challenges of particular PTMs, primarily focusing on the most frequent modifications.

Recently, we have proposed a redox molecular hypothesis about the natural biophysical substrate of visual perception and imagery [1,6]. Namely, the retina transforms external photon signals into electrical signals that are carried to the V1 (striatecortex). Then, V1 retinotopic electrical signals (spike-related electrical signals along classical axonal-dendritic pathways) can be converted into regulated ultraweak bioluminescent photons (biophotons) through redox processes within retinotopic visual neurons that make it possible to create intrinsic biophysical pictures during visual perception and imagery. However, the consensus opinion is to consider biophotons as by-products of cellular metabolism. This paper argues that biophotons are not by-products, other than originating from regulated cellular radical/redox processes. It also shows that the biophoton intensity can be considerably higher inside cells than outside. Our simple calculations, within a level of accuracy, suggest that the real biophoton intensity in retinotopic neurons may be sufficient for creating intrinsic biophysical picture representation of a single-object image during visual perception.

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The therapeutical use of drugs involves the application of dosage forms, serving as carrier systems together with several excipients to deliver the active ingredient to the site of action. Drug delivery technology combines an understanding of medicinal chemistry and pharmacology with the skill of formulation, aiming the preparation of improved pharmaceuticals. The recently introduced Biopharmaceutical Classification System provides guidance for dosage form design, taking the molecular and physico-chemical properties of drugs into consideration through their solubility and permeability characteristics. Pharmaceutical excipients used for oral dosage form have been traditionally assumed as being inert. However, recent experience and new results have shown that they can interact with the active drug ingredient, affecting its dissolution, absorption and bioavailability. Classification of the excipients is based on their role in the pharmaceutical formulation and on their interactions influencing drug delivery, based on their chemical and physico-chemical properties. The main classes are the antioxidants, coating materials, emulgents, taste- and smell-improvers, ointment bases, conserving agents, consistency-improvers and disintegrating materials. Some of the excipients may serve multiple purposes; for example, methylcellulose is a coating material, is applied in the preparation of suspensions, to increase viscosity, as a disintegrating agent or binder in tablets. The aim of this paper is to review the drug-excipients with respect to their chemistry, importance and interactions altering the pharmacokinetics of the drug substances. Emphasis will be given to two major classes of excipients: the antioxidants and disintegrants (substances facilitating disintegration of the drug tablets in the gastro-intestinal tract). Details will be given on the mechanisms through which they can alter drug effectiveness and tolerance, and control their application. Examples and references will be given for their analysis.

Baicalein, the aglycone formed by hydrolysis of baicalin in the intestine, is well absorbed by passive diffusion but subjected to extensive intestinal glucuronidation. Efflux of baicalin, the low passive permeability glucuronide of baicalein from enterocytes, likely depends on a carrier-mediated transport. The present study was designed to explore potential drug-herb interaction by investigating the inhibitory effect of baicalin on the transport of reporter substrates by transporters and to identify the transporters responsible for the efflux of baicalin from enterocytes and hepatocytes. The interaction of baicalin with specific ABC transporters was studied using membranes from cells overexpressing human BCRP, MDR1, MRP2, MRP3 and MRP4. Baicalin was tested for its potential to inhibit vesicular transport by these transporters. The transport of baicalin by the selected transporters was also investigated. Transport by BCRP, MRP3 and MRP4 was inhibited by baicalin with an IC50 of 3.41 ± 1.83 μM, 14.01 ± 2.51 μM and 14.39 ± 5.69 μM respectively. Inhibition of MDR1 (IC50  = 94.84 ± 31.10 μM) and MRP2 (IC50  = 210.13 ± 110.49 μM) was less potent. MRP2 and BCRP are the apical transporters of baicalin that may mediate luminal efflux in enterocytes and biliary efflux in hepatocytes. The basolateral efflux of baicalin is likely mediated by MRP3 and MRP4 both in enterocytes and hepatocytes. Via inhibition of transport by ABC transporters, baicalin could interfere with the absorption and disposition of drugs.