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Modern pharmaceutical technology still seeks new excipients and investigates the further use in already known ones. An example is magnesium aluminometasilicate Neusilin® US2 (NEU), a commonly used inert filler with unique properties that are usable in various pharmaceutical fields of interest. We aimed to explore its application in hypromellose matrix systems (HPMC content 10–30%) compared to the traditionally used microcrystalline cellulose (MCC) PH 102. The properties of powder mixtures and directly compressed tablets containing individual fillers NEU or MCC, or their blend with ratios of 1.5:1, 1:1, and 0.5:1 were investigated. Besides the routine pharmaceutical testing, we have enriched the matrices' evaluation with a biorelevant dynamic dissolution study and advanced statistical analysis. Under the USP apparatus 2 dissolution test, NEU, individually, did not provide advantages compared to MCC. The primary limitations were the burst effect increase followed by faster drug release at the 10–20% HPMC concentrations. However, the biorelevant dynamic dissolution study did not confirm these findings and showed similarities in dissolution profiles. It indicates the limitations of pharmacopoeial methods in matrix tablet development. Surprisingly, the NEU/MCC blend matrices at the same HPMC concentration showed technologically advantageous properties. Besides improved flowability, tablet hardness, and a positive impact on the in vitro drug dissolution profile toward zero-order kinetics, the USP 2 dissolution data of the samples N75M50 and N50M50 showed a similarity to those obtained from the dynamic biorelevant apparatus with multi-compartment structure. This finding demonstrates the more predictable in vivo behaviour of the developed matrix systems in human organisms. [ABSTRACT FROM AUTHOR]

The presented review article is a compilation of several foreign reviews and experimental papers, as well as several authority guidelines, which deal with the phenomenon of dose dumping of solid dosage forms with modified drug release. The aim of the publication is to present this often-neglected issue to a wider domestic audience. The work deals with two basic types of dose dumping, i.e., alcohol-induced dose dumping and food-induced dose dumping. It contains basic factors affecting this phenomenon as well as possible formulation solutions that can be used to eliminate it. Last but not least, the current requirements of the authorities are also mentioned, especially for testing newly introduced products with the presumed potential risk of dose dumping.

Currently, the method of external ionic gelation for the preparation of alginate particles is successfully used not only in the field of pharmacy and medicine, but also especially in the field of biotechnology. Therefore, the preparation of alginate particles and their subsequent evaluation using principal component analysis was the key task of our experiment. To optimize this method, we focused on the evaluation of the effect of formulation (the polymer concentration, the hardening solution concentration) and process parameters (the outer diameter of the injection needle) on the properties of the resulting beads (yield, sphericity factor, equivalent diameter and swelling capacity at pH 6). Using multivariate data analysis, the major influence on the resulting properties of the prepared particles was confirmed only in sodium alginate concentration. Obtained results verified the reliable and safe potential of the external ionic gelation for preparation alginate-based particulate dosage forms.

Size-reduced microparticles were successfully obtained by solvent evaporation method. Different parameters were applied in each sample and their influence on microparticles was evaluated. As a model drug the insoluble ibuprofen was selected for the encapsulation process with Eudragit® RS. The obtained microparticles were inspected by optical microscopy and scanning electron microscopy. The effect of aqueous phase volume (600, 400, 200 ml) and the concentration of polyvinyl alcohol (PVA; 1.0% and 0.1%) were studied. It was evaluated how those variations and also size can affect microparticle characteristics such as encapsulation efficiency, drug loading, burst effect and microparticle morphology. It was observed that the sample prepared with 600 ml aqueous phase and 1% concentration of polyvinyl alcohol gave the most favorable results.Key words: microparticles solvent evaporation sustained drug release Eudragit RS®.