scholarly journals Difference in the Dissolution Behaviors of Tablets Containing Polyvinylpolypyrrolidone (PVPP) Depending on Pharmaceutical Formulation After Storage Under High Temperature and Humid Conditions

2016 ◽  
Vol 19 (4) ◽  
pp. 511 ◽  
Author(s):  
Yoh Takekuma ◽  
Haruka Ishizaka ◽  
Masato Sumi ◽  
Yuki Sato ◽  
Mitsuru Sugawara
Keyword(s):  
High Temperature ◽  
Benzoic Acid ◽  
Dissolution Rate ◽  
Simple Structure ◽  
Pharmaceutical Formulations ◽  
Magnesium Stearate ◽  
Principal Agent ◽  
Amino Groups ◽  
Dissolution Tests ◽  
Rosuvastatin Calcium

PURPOSE. Storage under high temperature and humid conditions has been reported to decrease the dissolution rate for some kinds of tablets containing polyvinylpolypyrrolidone (PVPP) as a disintegrant. The aim of this study was to elucidate the properties of pharmaceutical formulations with PVPP that cause a decrease in the dissolution rate after storage under high temperature and humid conditions by using model tablets with a simple composition. METHODS. Model tablets, which consisted of rosuvastatin calcium or 5 simple structure compounds, salicylic acid, 2-aminodiphenylmethane, 2-aminobiphenyl, 2-(p-tolyl)benzoic acid or 4.4’-biphenol as principal agents, cellulose, lactose hydrate, PVPP and magnesium stearate as additives, were made by direct compression. The model tables were wrapped in paraffin papers and stored for 2 weeks at 40°C/75% relative humidity (RH). Dissolution tests were carried out by the paddle method in the Japanese Pharmacopoeia 16th edition. RESULTS. Model tablets with a simple composition were able to reproduce a decreased dissolution rate after storage at 40°C/75% RH. These tablets showed significantly decreased water absorption activities after storage. In the case of tablets without lactose hydrate by replacing with cellulose, a decreased dissolution rate was not observed. Carboxyl and amino groups in the structure of the principal agent were not directly involved in the decreased dissolution. 2-Benzylaniline tablets showed a remarkably decreased dissolution rate and 2-aminobiphenyl and 2-(p-tolyl)benzoic acid tablets showed slightly decreased dissolution rates, though 4,4’-biphenol tablets did not show a decrease dissolution rate. CONCLUSIONS. We demonstrated that additives and structure of the principal agent were involved in the decreased in dissolution rate for tablets with PVPP. The results suggested that one of the reasons for a decreased dissolution rate was the inclusion of lactose hydrate in tablets. The results also indicated that compounds as principal agents with low affinity for PVPP may be easily affected by airborne water under high temperature and humid conditions. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.

scholarly journals Formulation development and evaluation of Silybum marianum tablets

Rodriguésia ◽  
2020 ◽  
Vol 71 ◽  
Author(s):  
Valeria Andrea Cianchino ◽  
Laura Silvina Favier ◽  
Claudia Alicia Ortega ◽  
Cecilia Peralta ◽  
Diego Alberto Cifuente
Keyword(s):  
Ethanolic Extract ◽  
Soxhlet Extraction ◽  
Pharmaceutical Formulations ◽  
Magnesium Stearate ◽  
Major Constituent ◽  
Active Principle ◽  
Formulation Development ◽  
Silybum Marianum ◽  
Disintegration Time ◽  
Popular Medicine

Abstract In popular medicine Silybum marianum is used as a hepatoprotective agent. Silymarin is the major constituent. The present work deals with the formulation and evaluation of S. marianum tablets from ethanolic extract by direct compression. The ethanolic extract was obtained from seeds by soxhlet extraction. Two pharmaceutical formulations were prepared using fluid extract as an active principle, and Aeroperl® 300 Pharma as a carrier. In order to improve flow ability and compressibility, co-processed excipients MicroceLac® 100 and FlowLac® 90 were employed. Pre-compression and post-compression parameters were evaluated according to USP 34-NF 29. Besides, silymarin was determined by NMR spectral data. Both formulations showed excellent rheological properties and the best biopharmaceutical parameters were observed in F2 (S. marianum ethanolic extract, aeroperl® 300 Pharma, flowLac® 90, glycolate starch and magnesium stearate) in terms of the friability (0.82 %) and the disintegration time (8.05 min).

Differential Scanning Calorimetric Analysis for Incompatibility: Sodium Stearate/Magnesium Stearate and Acidic Compounds

2020 ◽  
Vol 859 ◽  
pp. 307-312
Author(s):  
Pornsit Chaiya ◽  
Thawatchai Phaechamud
Keyword(s):  
Sodium Stearate ◽  
Pharmaceutical Formulations ◽  
Pharmaceutical Compounds ◽  
Magnesium Stearate ◽  
Differential Scanning Calorimetric ◽  
Salt Form ◽  
Scanning Calorimetry ◽  
Calorimetric Analysis ◽  
Pharmaceutical Excipient ◽  
Acidic Compounds

Compatibility investigation was performed between stearate lubricants (sodium stearate and magnesium stearate) and acidic pharmaceutical compounds (ibuprofen, indomethacin and valproic acid) and citric acid as acidic pharmaceutical excipient using differential scanning calorimetry (DSC). Alteration in DSC thermogram was found in all mixtures. There was a presence of melting endothermic peak of stearic acid in all mixtures (except that of stearate lubricants and indomethacin) indicating breakage of salt form of stearate lubricants depended on the physicochemical properties of drug compounds and pharmaceutical excipient. Therefore, the avoidance for using stearate lubricants with acidic pharmaceutical compounds and excipient should be concerned in development of pharmaceutical formulations.

scholarly journals The interaction of spermine and pentamines with DNA

1987 ◽  
Vol 244 (1) ◽  
pp. 243-246 ◽  
Author(s):  
H S Basu ◽  
L J Marton
Keyword(s):  
High Temperature ◽  
Melting Temperature ◽  
Conformational Changes ◽  
Thermus Thermophilus ◽  
Total Charge ◽  
Amino Groups ◽  
Carbon Chains ◽  
Naturally Occurring ◽  
Calf Thymus

We studied the effects of spermine, two naturally-occurring pentamines isolated from the thermophile Thermus thermophilus and one synthetic pentamine on the aggregation and ‘melting’ temperature of calf-thymus DNA and on the B-to-Z transition of poly(dG-me5dC). All pentamines caused aggregation of DNA at much lower concentrations than that of spermine. Concentrations that increased the melting temperature of DNA and induced the B-to-Z transition in poly(dG-me5dC) were different for each pentamine, but were comparable with the concentration of spermine needed to cause these effects. Our results suggest that both the total charge and the distance separating the charge, which is a function of the length of the carbon chains between amino groups, are important for the induction of conformational changes in DNA. The biological role of pentamines in T. thermophilus appears to be related to their ability to promote DNA condensation at high temperature.

Basic Experiment on Lithium Removal Technique

2012 ◽  
Author(s):  
Tomohiro Furukawa ◽  
Yasushi Hirakawa
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Dissolution Rate ◽  
Chemical Reaction ◽  
Pure Water ◽  
Preliminary Investigation ◽  
Testing Temperature ◽  
Temperature Range ◽  
Removal Technique ◽  
Good Agreement

As a preliminary investigation into the establishment of a lithium removal technique for the components used at the International Fusion Materials Irradiation Facility (IFMIF), experiments were performed on the dissolution of lithium in three solvents: ethanol, pure water, and ethanol–water. In these experiments, hemispherical lithium was immersed in the solvents at constant temperatures, and the degree of dissolution was measured continuously from the height of the sample. From the obtained data, the average dissolution rate in the solvents at each testing temperature (10–90 °C) and the amount of hydrogen generated by the chemical reaction were calculated. The average dissolution rates in ethanol, pure water, and ethanol–water at 30 °C were 0.01, 1.6, and 0.43 mm/min, respectively. Although the average dissolution rate increased with the testing temperature in the low-temperature range (10–50 °C) for all solvents, this increase was saturated in the high-temperature range (50–90 °C) in experiments with pure water and ethanol–water as solvents. The volume of gas collected during each experiment was in good agreement with the volume of hydrogen assumed to be generated from the chemical reaction of lithium with the solvents.

The High Temperature and Dilute Acid (HTDA) Procedure as a General Method of Replacing Aromatic Hydrogen by Deuterium. II

1974 ◽  
Vol 52 (11) ◽  
pp. 2169-2171 ◽  
Author(s):  
Nick H. Werstiuk ◽  
Tony Kadai
Keyword(s):  
High Temperature ◽  
Benzoic Acid ◽  
Dilute Acid ◽  
General Method ◽  
Aromatic Hydrogen

The preparation of aniline-d5, phenol-d5, and benzoic acid-d5 utilizing the conditions of high temperature and dilute acid (HTDA) is described.

Helical poly(phenylacetylene)s containing schiff-base and amino groups: Synthesis, secondary structures, and responsiveness to benzoic acid

2013 ◽  
Vol 51 (24) ◽  
pp. 5248-5256 ◽  
Author(s):  
Yu Zhang ◽  
Keke Gao ◽  
Zhongfu Zhao ◽  
Dongmei Yue ◽  
Yanming Hu ◽  
...  
Keyword(s):  
Schiff Base ◽  
Benzoic Acid ◽  
Secondary Structures ◽  
Amino Groups

scholarly journals Dissolution Rates of DWPF Glasses from Long-Term PCT

1996 ◽  
Vol 465 ◽  
Author(s):  
W. L. Ebert ◽  
S.-W. Tam
Keyword(s):  
Dissolution Rate ◽  
Surface Area ◽  
Spherical Particles ◽  
Dissolution Rates ◽  
Glass Dissolution ◽  
Dissolution Tests ◽  
Dissolution Model ◽  
Advanced Stages ◽  
Radionuclide Release

ABSTRACTWe have characterized the corrosion behavior of several Defense Waste Processing Facility (DWPF) reference waste glasses by conducting static dissolution tests with crushed glasses. Glass dissolution rates were calculated from measured B concentrations in tests conducted for up to five years. The dissolution rates of all glasses increased significantly after certain alteration phases precipitated. Calculation of the dissolution rates was complicated by the decrease in the available surface area as the glass dissolves. We took the loss of surface area into account by modeling the particles to be spheres, then extracting from the short-term test results the dissolution rate corresponding to a linear decrease in the radius of spherical particles. The measured extent of dissolution in tests conducted for longer times was less than predicted with this linear dissolution model. This indicates that advanced stages of corrosion are affected by another process besides dissolution, which we believe to be associated with a decrease in the precipitation rate of the alteration phases. These results show that the dissolution rate measured soon after the formation of certain alteration phases provides an upper limit for the long-term dissolution rate, and can be used to determine a bounding value for the source term for radionuclide release from waste glasses. The long-term dissolution rates measured in tests at 20,000 m−1 at 90°C in tuff groundwater at pH values near 12 are about 0.2,0.07, and 0.04 g/(m2•d) for the Environmental Assessment glass and glasses made with SRL 131 and SRL 202 frits, respectively.

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