Diatoms are widespread unicellular photosynthetic algae that produce unique highly ordered siliceous cell wall, called frustule. Micro-to nanoporous structure with high surface area that can be easily modified, high mechanical resistance, unique optical features (light focusing and luminescence) and biocompatibility make diatom frustule as a suitable raw material for the development of devices such as bio-and gas sensors, microfluidic particle sorting devices, supercapacitors, batteries, solar cells, electroluminescent devices and drug delivery systems. Their wide availability in the form of fossil remains (diatomite or diatomaceous earth) as well as easy cultivation in the artificial conditions further supports use of diatoms in many different fields of application. This review focused on the recent achievements in the diatom bioapplications such as drug delivery, biomolecules immobilization, bio-and gas sensing, since great progress was made in this field over the last several years.

This article presents the possibility of using of multiple regression analysis (MRA) and dynamic neural network (DNN) for prediction of stability of Hydrocortisone 100 mg (in a form of hydrocortisone sodium succinate) freeze-dried powder for injection packed into a dual chamber container. Degradation products of hydrocortisone sodium succinate: free hydrocortisone and related substances (impurities A, B, C, D and E; unspecified impurities and total impurities) were followed during stress and formal stability studies. All data obtained during stability studies were used for in silico modeling; multiple regression models and dynamic neural networks as well, in order to compare predicted and observed results. High values of coefficient of determination (0.950.99) were gained using MRA and DNN, so both methods are powerful tools for in silico stability studies, but superiority of DNN over mathematical modeling of degradation was also confirmed

In order to achieve fast release of ibuprofen, slightly soluble model substance (0.52104 mol/l), surfactant systems for oral use with different PEG-40 hydrogenated castor oil (C)/diethylene glycol monoethyl ether (T) ratios were investigated. Comparison between dissolution profiles for ibuprofen from formulated systems and from two commercial products, film tablets and soft capsules, is presented in this paper. Photon correlation spectroscopy has shown that after high dilution with water, surfactant systems were able to form micellar solutions. The size of micelles varies from 14.8 ± 0,075 nm to 16.2 ± 0,021 nm with increasing C/T ratio from 1:2 to 2:1. Although with increasing content of PEG-40 hydrogenated castor oil larger micelles have formed, lower values of polydispersity index indicated that more homogeneous distribution of micelles size was gained. Conductometric analysis has demonstrated that system composing of C/T ratio 2:1, has shown most pronounced interaction between droplets, which can be seen as high rise of electrical conductivity with increasing water content (% (wwater/wtotal)) in the sample. No significant difference in percolation threshold between formulations with different C/T ratios was observed. Different surfactant systems were adsorbed on magnesium aluminometasilicate, as adsorbent with high specific active surface (≈300 m2/g), in order to investigate potential influence of adsorbent on ibuprofen dissolution rate. Formulated systems, with or without adsorbent were filled in hard gelatin capsules. The dissolution profiles of ibuprofen from different formulations were obtained in 30 minutes by dissolution apparatus with rotating baskets and compared with dissolution profiles of ibuprofen from commercial products. For formulations without adsorbent faster release of ibuprofen in first minutes of dissolution test, showed formulations with C/T ratio 2:1 and 1:1. Magnesium aluminometasilicate, as adsorbent with high specific surface area, significantly improved release rate of ibuprofen from formulation with C/T ratio 2:1, but, for formulation with C/T ratio 1:1, significantly lower release of ibuprofen was observed. Formulations with other C/T ratios in terms of fast ibuprofen release did not give satisfying results. Obtained results show that in comparison to dissolution profile of ibuprofen from commercial products proper C/T ratio as well as magnesium aluminometasilicate, as adsorbent with high specific surface area, can significantly increase release of ibuprofen

This study investigates the use of high molecular weight polyethylene oxide (PEO WSR coagulant) for the preparation of sustained release matrix tablets containing high dose, highly water soluble drug, tramadol HCl. Proportion of PEO polymer, type of insoluble filler, proportion of tramadol HCl, amount of drug in tablet, tablet diameter and compression pressure were recognized as critical formulation and process parameters and their influence on drug release and tablet mechanical properties was evaluated. Percentages of tramadol HCl released after 30 and 240 min were selected for evaluation of drug release, while tensile strength was used as indicator of tablet mechanical properties. Only proportion of tramadol HCl exhibits statistically significant effect on percentages of tramadol HCl released after 30 and 240 min, with higher, wherein increasing of the tramadol HCl proportion increased its release rate among the evaluated variables in selected ranges. All of the investigated factors exhibit statistically significant effect on tablets tensile strength, with the largest influence of filler type. Tablets prepared with highly compressible filler (microcrystalline cellulose) exhibit higher tensile strength and therefore better mechanical properties to those prepared with partially pregelatinized starch (starch 1500).

The importance of biopharmaceutical considerations in pharmaceutical development and drug characterization has been well recognized both by pharmaceutical industry and regulatory authorities as a tool to establish predictive relationships between drug product quality attributes (in vitro data) and its clinical performance (in vivo data). In the present paper, contemporary biopharmaceutics toolkit including in vivo predictive dissolution testing, Biopharmaceutics Classification System, physiologically based pharmacokinetic and biopharmaceutics modeling and simulation, in vitro-in vivo correlation and biowaiver, are reviewed with regards to relevant general principles and applicability. The recently introduced innovative strategy for patient-centric drug development using an integrated systems approach grounded in fundamental biopharmaceutics concepts, clinical insights and therapeutic drug delivery targets, described as Biopharmaceutics Risk Assessment Roadmap (BioRAM) is also presented. Further development in the field will benefit from joint efforts and exchange of knowledge and experiences between pharmaceutical industry and regulatory authorities for the common goal to accelerate development of effective and safe drug products designed in accordance with patients? needs and expectations.