scholarly journals Impact of Magnesium Stearate Presence and Variability on Drug Apparent Solubility Based on Drug Physicochemical Properties

2020 ◽  
Vol 22 (4) ◽  
Author(s):  
P. Zarmpi ◽  
T. Flanagan ◽  
E. Meehan ◽  
J. Mann ◽  
Nikoletta Fotaki
Keyword(s):  
Physicochemical Properties ◽  
Magnesium Stearate ◽  
Apparent Solubility

scholarly journals Combinations of Freeze-Dried Amorphous Vardenafil Hydrochloride with Saccharides as A Way to Enhance Dissolution Rate and Permeability

2021 ◽  
Vol 14 (5) ◽  
pp. 453
Author(s):  
Gabriela Wiergowska ◽  
Dominika Ludowicz ◽  
Kamil Wdowiak ◽  
Andrzej Miklaszewski ◽  
Kornelia Lewandowska ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Density Functional ◽  
Hydroxypropyl Methylcellulose ◽  
Fold Increase ◽  
Crystalline Form ◽  
Amorphous Form ◽  
Freeze Dried ◽  
Apparent Solubility ◽  
Gastrointestinal Epithelium ◽  
The Impact

To improve physicochemical properties of vardenafil hydrochloride (VAR), its amorphous form and combinations with excipients—hydroxypropyl methylcellulose (HPMC) and β-cyclodextrin (β-CD)—were prepared. The impact of the modification on physicochemical properties was estimated by comparing amorphous mixtures of VAR to their crystalline form. The amorphous form of VAR was obtained as a result of the freeze-drying process. Confirmation of the identity of the amorphous dispersion of VAR was obtained through the use of comprehensive analysis techniques—X-ray powder diffraction (PXRD) and differential scanning calorimetry (DSC), supported by FT-IR (Fourier-transform infrared spectroscopy) coupled with density functional theory (DFT) calculations. The amorphous mixtures of VAR increased its apparent solubility compared to the crystalline form. Moreover, a nearly 1.3-fold increase of amorphous VAR permeability through membranes simulating gastrointestinal epithelium as a consequence of the changes of apparent solubility (Papp crystalline VAR = 6.83 × 10−6 cm/s vs. Papp amorphous VAR = 8.75 × 10−6 cm/s) was observed, especially for its combinations with β-CD in the ratio of 1:5—more than 1.5-fold increase (Papp amorphous VAR = 8.75 × 10−6 cm/s vs. Papp amorphous VAR:β-CD 1:5 = 13.43 × 10−6 cm/s). The stability of the amorphous VAR was confirmed for 7 months. The HPMC and β-CD are effective modifiers of its apparent solubility and permeation through membranes simulating gastrointestinal epithelium, suggesting a possibility of a stronger pharmacological effect.

Evaluating retardation and physicochemical properties of co-ground mixture of Na- diclofenac with magnesium stearate

2012 ◽  
Vol 218 ◽  
pp. 51-56 ◽  
Author(s):  
Yousef Javadzadeh ◽  
Khosro Adibkia ◽  
Zahra Bozorgmehr ◽  
Siavash Dastmalchi
Keyword(s):  
Physicochemical Properties ◽  
Magnesium Stearate ◽  
Ground Mixture

scholarly journals The Influence of Excipients on the Physicochemical and Biological Properties of a Bactericidal, Labile Ester Prodrug in a Salt Form – A Case Study of Cefetamet Pivoxil Hydrochloride

2018 ◽  
Vol 15 (2) ◽  
pp. 6218-6234
Author(s):  
Jakub Dzitko ◽  
Przemyslaw Zalewski ◽  
Daria Szymanowska ◽  
Piotr Garbacki ◽  
Magdalena Paczkowska ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Bacterial Infections ◽  
Ph Value ◽  
Drug Carrier ◽  
Methyl Cellulose ◽  
Magnesium Stearate ◽  
Biological Properties ◽  
Pharmacological Potential ◽  
Ester Prodrug

The article presents an innovative approach to a bactericidal drug design based on a cephem prodrug analogue – cefetamet pivoxil hydrochloride. The emergence of cefetamet pivoxil hydrochloride excipient systems (mannitol, hydroxypropyl methyl cellulose, pregelatinised starch, lactose monohydrate, magnesium stearate, polyvinylpyrrolidone) caused changes in the physicochemical properties of cefetamet pivoxil hydrochloride. They are significant for planning the development of an innovative pharmaceutical formulation. The biological activity profile of the prodrug was also modified. FTIR spectra were used to study interactions between cefetamet pivoxil hydrochloride and the excipients. The theoretical approach to the analysis of experimental spectra enabled precise indication of cefetamet pivoxil hydrochloride domains responsible for interaction with the excipients. The interactions between cefetamet pivoxil hydrochloride and the excipients resulted in some  important physicochemical modifications: acceptor fluid-dependent changes in solubility and the dissolving rate as well as a decrease in the chemical stability of cefetamet pivoxil hydrochloride in the solid state, especially during thermolysis. The interactions between cefetamet pivoxil hydrochloride and the excipients also had biologically essential effects. There were changes in its permeability through artificial biological membranes simulating the gastrointestinal tract, which depended on the pH value of the acceptor solution. Cefetamet pivoxil hydrochloride combined with the excipient systems exhibited greater bactericidal potential against Staphylococcus aureus. Its bactericidal potential against Enterococcus faecalis, Pseudomonas aeruginosa and Proteus mirabilis doubled. The new approach provides an opportunity to develop treatment of resistant bacterial infections. It will enable synergy between the excipient and the pharmacological potential of an active pharmaceutical substance with modified physicochemical properties induced by the drug carrier.

scholarly journals Development of Compositions and Technologies for Producing Tablets with Hydroxythyrozol-standardized Extract of Olive Leaves

2021 ◽  
Vol 10 (3) ◽  
pp. 47-53
Author(s):  
M. S. Maslennikova ◽  
N. L. Solovyova
Keyword(s):  
Physicochemical Properties ◽  
Quality Indicators ◽  
Potato Starch ◽  
Olive Tree ◽  
Magnesium Stearate ◽  
Biological Properties ◽  
Reversed Phase ◽  
Biologically Active ◽  
Olive Leaves ◽  
Dry Extract

Introduction. The article presents the results of a study of the physicochemical properties of dry extract of olive leaves, standardized by hydroxythyrozol - a biologically active substance that is part of the chemical composition of aerial parts of the olive tree.Aim. The purpose of the study is to develop tablet Formulations containing dry extract of olive leaves and to standardize by hydroxythyrozol by reversed-phase-HPLC method on the main substancecontent.Materials and methods. Substance of dry extract of olive leaves, microcrystalline cellulose (Avicel® PH-112), Aerosil® (Aeroperl® 300 Pharma), Ludipress® (Ludipress®), lactose, potato starch, sodium salt of carboxymethyl starch, magnesium stearate, direct pressing, HPLC.Results and discussion. Studies of the physicochemical properties of dry extract of olive leaves have been carried out. Selected excipients for the study of tablettable masses. Formulations for further tabletting have been developed. A complex of studies of the obtained tablets was carried out according to Russian Pharmacopoeia XIV for compliance with quality indicators.Conclusion. The biological properties of dry extract of olive leaves are have been studied, indicating the prospect of developing drugs based on it. Formulations of tablets with dry extract of olive leaves have been developed and their quality indicators have been investigated.

Preparation and characterisation of vanadium pentoxide supported rhodium catalyst

1988 ◽  
Vol 46 ◽  
pp. 946-947
Author(s):  
A. Legrouri
Keyword(s):  
Aqueous Solution ◽  
Thermal Decomposition ◽  
Physicochemical Properties ◽  
Surface Area ◽  
Vanadium Pentoxide ◽  
High Purity ◽  
Gas Adsorption ◽  
Rhodium Catalyst ◽  
Optical Methods ◽  
Reducible Oxides

The industrial importance of metal catalysts supported on reducible oxides has stimulated considerable interest during the last few years. This presentation reports on the study of the physicochemical properties of metallic rhodium supported on vanadium pentoxide (Rh/V2O5). Electron optical methods, in conjunction with other techniques, were used to characterise the catalyst before its use in the hydrogenolysis of butane; a reaction for which Rh metal is known to be among the most active catalysts.V2O5 powder was prepared by thermal decomposition of high purity ammonium metavanadate in air at 400 °C for 2 hours. Previous studies of the microstructure of this compound, by HREM, SEM and gas adsorption, showed it to be non— porous with a very low surface area of 6m2/g3. The metal loading of the catalyst used was lwt%Rh on V2Q5. It was prepared by wet impregnating the support with an aqueous solution of RhCI3.3H2O.

Studies on the Degradation of Human Fibrinogen by Plasmin and Trypsin

1966 ◽  
Vol 16 (03/04) ◽  
pp. 526-540 ◽  
Author(s):  
E. A Beck ◽  
D. P Jackson
Keyword(s):  
Physicochemical Properties ◽  
Electrophoretic Mobility ◽  
Rapid Loss ◽  
Clotting System ◽  
Human Fibrinogen ◽  
Peptide Bonds ◽  
Physico Chemical ◽  
Starch Gel ◽  
Ph Stat ◽  
Rapid Appearance

SummaryThe effects of trypsin and plasmin on the functional and physicochemical properties of purified human fibrinogen were observed at various stages of proteolysis. Concentrations of plasmin and trypsin that produced fibrinogenolysis at comparable rates as measured in a pH stat produced, at similar rates, loss of precipitability of fibrinogen by heat and ammonium sulphate and alterations in electrophoretic mobility on starch gel. Trypsin produced a more rapid loss of clottability of fibrinogen and a more rapid appearance of inhibitors of the thrombin-fibrinogen clotting system than did plasmin. Consistent differences were noted between the effects of trypsin and plasmin on the immunoelectrophoretic properties of fibrinogen during the early stages of proteolysis.These results are consistent with the hypothesis that trypsin initially reacts with the same peptide bonds of fibrinogen that are split by thrombin, but these same bonds do not appear to be split initially by plasmin. Measurement of the various functional and physico-chemical changes produced by the action of trypsin and plasmin on fibrinogen can be used to recognize various stages of proteolysis.

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