Reliable stabilization of the pharmaceutical preparation and the active ingredient remains one of the most important problems of world pharmacy because pharmaceutical preparations are not systems which are stable without limitation. The patient must receive a quality drug and that is why the question of stability is paid grest attention to not only in research and development, industrial manufacture, but also in distribution. The measure of stability is the expiration period. Diluted solution of hydrogen peroxide (3% solution) still belongs to the most widely used and at the same time the most easily accessible disinfectants. In practice it is common both in Slovakia and abroad. It is used in several concentrations. One of its most important disadvantages is its limited stability, which markedly decreases its expiration period. The present paper investigates the stability of hydrogen peroxide solutions of routinely used concentrations (3%, 6%, and 10%) without and with a stabilizing additive (phenacetin) prepared in the pharmacy and stored under different conditions for the period of their expected usability. The content of hydrogen peroxide was assayed by the pharmacopoeial method in 7-day time intervals. All concentrations of 3%, 6%, and 10% hydrogen peroxide were found to fulfil the conditions for stability in the period of time under study. Their concentration did not fall below the limit od 90% of the content of the active ingredient, and storage under decreased temperature proved to be more suitable. Storage of hydrogen peroxide in the light is inadmissible. When the conditions of storage are observed, the required therapeutic effect of hydrogen peroxide solution can be expected for the period of three months.

• MeSH
• peroxid vodíku chemie   MeSH
• roztoky MeSH
• skladování léků MeSH
• stabilita léku MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH
• Názvy látek
• peroxid vodíku MeSH
• roztoky MeSH

Osmolytes are essential for cellular function under ubiquitous osmotic stress. Trimethylamine N-oxide (TMAO) is one such osmolyte that has gained remarkable attention due to its protein-protective ability against urea. This Review aims at providing a detailed account of recent theoretical and experimental developments in characterizing the structural changes and thermodynamic stability of proteins in the presence of TMAO and urea. New vapor pressure osmometry and molecular dynamics simulation results on urea-TMAO solutions are presented, and a unified molecular mechanism of TMAO counteraction of urea-induced protein denaturation is introduced. In addition, a detailed technical assessment of molecular dynamics force fields for TMAO and for urea-TMAO solutions is presented. The force field analysis highlights how many of the commonly used force field models are in fact incompatible with solvation thermodynamics and can lead to misleading conclusions. A new optimized force field for TMAO (Shea(m)) is presented, and a recently optimized force field for TMAO-urea (Netz(m)) that best reproduces experimental data is highlighted.

• MeSH
• methylaminy MeSH
• močovina * MeSH
• roztoky MeSH
• stabilita proteinů MeSH
• voda * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Research Support, N.I.H., Extramural MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Názvy látek
• methylaminy MeSH
• močovina * MeSH
• roztoky MeSH
• trimethyloxamine MeSH Prohlížeč
• voda * MeSH

Stability studies represent an essential component of pharmaceutical development, enabling critical evaluation of the therapeutic potential of an active pharmaceutical ingredient (API) or a final pharmaceutical product under the influence of various environmental factors. The aim of the present study was to investigate the chemical stability of cannabidiol (CBD) in the form of a solid powder (hereinafter referred to as CBD powder) and also dissolved in sunflower oil. We performed stress studies in accordance with the International Conference on Harmonization (ICH) guidelines, where 5 mg of marketed CBD in the form of a solid powder and in form of oil solution were exposed for 7 and 14, 30, 60, 90, 180, 270, and 365 days to precisely defined temperature and humidity conditions, 25 °C ± 2 °C/60% RH ± 5% and 40 °C ± 2 °C/75% RH ± 5% in both open and closed vials in the dark. CBD powder was significantly more stable than CBD in oil solution. Such finding is important because CBD is often administered dissolved in oil matrix in practice due to very good bioavailability. Thus, the knowledge on admissible shelf time is of paramount importance.

• Klíčová slova
• cannabidiol, cannabinol, degradation, oil matrix, stability study, tetrahydrocannabinol,
• Publikační typ
• časopisecké články MeSH

Dioxopromethazine began to be used in therapy as a modern antihistamine agent in the 1970s. A dioxopromethazine-containing ophthalmic instillation and a gel were employed until the end of the 1990s. The paper deals with the examination of the stability of the drug dioxopromethazine in aqueous solutions and the ophthalmic instillation Promefrin stored under different conditions. High-performance liquid chromatography with spectrophotometrical and electrochemical detection and HPLC connected on-line with mass spectrometry were employed for analysis. Dioxopromethazine in aqueous solutions and in ophthalmic instillations stored in direct sunlight was found not to be stable. However, the cover of the ophthalmic instillation, a brown-glass prescription bottle, and observation of storing conditions sufficiently protect the active ingredient from decomposition processes.

• MeSH
• antagonisté histaminu H1 chemie   MeSH
• farmaceutická chemie MeSH
• oční roztoky chemie   MeSH
• promethazin analogy a deriváty   chemie   MeSH
• skladování léků MeSH
• stabilita léku MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antagonisté histaminu H1 MeSH
• dioxopromethazine MeSH Prohlížeč
• oční roztoky MeSH
• promethazin MeSH

• MeSH
• cykloserin * MeSH
• farmaceutická chemie MeSH
• roztoky MeSH
• stabilita léku MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• cykloserin * MeSH
• roztoky MeSH

Using a combination of molecular dynamics simulation, dialysis experiments, and electronic circular dichroism measurements, we studied the solvation thermodynamics of proteins in two osmolyte solutions, trimethylamine N-oxide (TMAO) and betaine. We showed that existing force fields are unable to capture the solvation properties of the proteins lysozyme and ribonuclease T1 and that the inaccurate parametrization of protein-osmolyte interactions in these force fields promoted an unphysical strong thermal denaturation of the trpcage protein. We developed a novel force field for betaine (the KBB force field) which reproduces the experimental solution Kirkwood-Buff integrals and density. We further introduced appropriate scaling to protein-osmolyte interactions in both the betaine and TMAO force fields which led to successful reproduction of experimental protein-osmolyte preferential binding coefficients for lysozyme and ribonuclease T1 and prevention of the unphysical denaturation of trpcage in osmolyte solutions. Correct parametrization of protein-TMAO interactions also led to the stabilization of the collapsed conformations of a disordered elastin-like peptide, while the uncorrected parameters destabilized the collapsed structures. Our results establish that the thermodynamic stability of proteins in both betaine and TMAO solutions is governed by osmolyte exclusion from proteins.

• MeSH
• betain * MeSH
• guanyloribonukleasa metabolismus   MeSH
• methylaminy chemie   MeSH
• muramidasa * metabolismus   MeSH
• roztoky MeSH
• stabilita proteinů MeSH
• termodynamika MeSH
• voda chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• betain * MeSH
• guanyloribonukleasa MeSH
• methylaminy MeSH
• muramidasa * MeSH
• roztoky MeSH
• trimethyloxamine MeSH Prohlížeč
• voda MeSH

The stability of aqueous protein solutions is strongly affected by multivalent ions, which induce ion-ion correlations beyond the scope of classical mean-field theory. Using all-atom molecular dynamics (MD) and coarse grained Monte Carlo (MC) simulations, we investigate the interaction between a pair of protein molecules in 3:1 electrolyte solution. In agreement with available experimental findings of "reentrant protein condensation", we observe an anomalous trend in the protein-protein potential of mean force with increasing electrolyte concentration in the order: (i) double-layer repulsion, (ii) ion-ion correlation attraction, (iii) overcharge repulsion, and in excess of 1:1 salt, (iv) non Coulombic attraction. To efficiently sample configurational space we explore hybrid continuum solvent models, applicable to many-protein systems, where weakly coupled ions are treated implicitly, while strongly coupled ones are treated explicitly. Good agreement is found with the primitive model of electrolytes, as well as with atomic models of protein and solvent.

• MeSH
• lidé MeSH
• lidský sérový albumin chemie   MeSH
• metoda Monte Carlo MeSH
• roztoky MeSH
• simulace molekulární dynamiky * MeSH
• soli chemie   MeSH
• stabilita proteinů MeSH
• vazba proteinů MeSH
• ytrium chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• lidský sérový albumin MeSH
• roztoky MeSH
• soli MeSH
• ytrium MeSH

The thermal stability of the monosubstituted cationic cyclodextrin (CD) derivatives PEMEDA-β-CD and PEMPDA-β-CD, which differ in their substituent linker length (ethylene and propylene, respectively), was studied via (1)H NMR experiments. PEMPDA-β-CD exhibited higher resistance towards the Hofmann degradation and was chosen as a more suitable host molecule for further studies. Inclusion properties of PEMPDA-β-CD in solution with a series of simple aromatic guests (salicylic acid, p-methoxyphenol and p-nitroaniline) were determined by isothermal titration calorimetry (ITC) and compared to the native β-CD. Permanently charged cationic CD derivatives were successfully deposited on the anionic solid surface of polymeric Nafion(®) 117 membrane via electrostatic interactions. Deposition kinetics and coverage of the surface were determined by ELSD. Finally, the ability of the CD derivatives bound to the solid surface to encapsulate aromatic compounds from aqueous solution was measured by UV-vis spectroscopy. The obtained results are promising for future industrial applications of the monosubstituted β-CD derivatives, because the preparation of cationic CD derivatives is applicable in large scale, without the need of chromatographic purification. Their ionic deposition on a solid surface is simple, yet robust and a straightforward process as well.

• Klíčová slova
• cyclodextrins, inclusion properties, solid surface, tetraalkylammonium derivatives, thermal stability,
• Publikační typ
• časopisecké články MeSH

Two decontamination solutions, commercially produced BASE•128 and laboratory decontamination solution (LDS), with analogous content of antibiotic and antimycotic agents, were compared in their antimicrobial efficiency and stability (pH and osmolarity). Both solutions were compared immediately after thawing aliquots frozen for 1, 3 or 6 months. Agar well diffusion method was used to test their antimicrobial efficiency against five human pathogens: Staphylococcus aureus, Pseudomonas aeruginosa, Proteus mirabilis, Escherichia coli and Enterococcus faecalis. The difference in the inhibition of growth between the two decontamination solutions was mostly not statistically significant, with few exceptions. The most pronounced difference between the LDS and BASE•128 was observed in their decontamination efficacy against E. coli and E. faecalis, where the LDS showed to be more efficient than BASE•128. The osmolarity value of LDS decreased with cold-storage, the osmolarity values of the BASE•128 could not be measured as they were below the range of the osmometer. Slight changes were found in pH of the less stable LDS solution, whose pH increased from initial value 7.36 ± 0.07 to 7.72 ± 0.19 after 6 m-storage. We verified that BASE•128 and LDS are similarly efficient in elimination of possible placental bacterial contaminants and may be used for decontamination of various tissues.

• Klíčová slova
• Amniotic membrane decontamination, Antimicrobial efficiency, Decontamination solution, Tissue decontamination,
• MeSH
• antibakteriální látky farmakologie   MeSH
• antiinfekční látky farmakologie   MeSH
• Bacteria účinky léků   MeSH
• dekontaminace * MeSH
• koncentrace vodíkových iontů MeSH
• mikrobiální testy citlivosti MeSH
• osmolární koncentrace MeSH
• roztoky MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antibakteriální látky MeSH
• antiinfekční látky MeSH
• roztoky MeSH

• MeSH
• fenoly * MeSH
• stabilita léku * MeSH
• vakcína proti pravým neštovicím * MeSH
• virus vakcinie * MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• fenoly * MeSH
• vakcína proti pravým neštovicím * MeSH