Solvent-Evaporation Induced and Mechanistic Entropy-Enthalpy-Balance Controlled Polymer Patch Formation on Nanoparticle Surfaces

2021 ◽  
pp. 7100-7105
Author(s):  
Linxiuzi Yu ◽  
Niboqia Zhang ◽  
Ning-Ning Zhang ◽  
Qianqian Gu ◽  
Yao Xue ◽  
...  
Keyword(s):  
Solvent Evaporation ◽  
Enthalpy Balance

Morphological transformations in solution-cast Styrene-Butadiene-Styrene (SBS) triblock copolymer thin films

1995 ◽  
Vol 53 ◽  
pp. 184-185
Author(s):  
Ginam Kim ◽  
W. Marsillo ◽  
M. Libera
Keyword(s):  
Thin Films ◽  
Triblock Copolymer ◽  
Annealing Treatment ◽  
Minor Component ◽  
Solvent Evaporation ◽  
Single Crystal Substrate ◽  
Transparent Films ◽  
Crystal Substrate ◽  
Solution Cast ◽  
Morphological Transformations

The fact that block copolymers can assume a range of morphologies depending upon such variables as relative block length and molecular weight is now well known. In the case of poly(styrene)[PS]-poly(butadiene)[PB]-poly(styrene) (SBS) triblock copolymer, the morphologies range from spheres (roughly ~20% minor component), to cylinders (roughly 20%~35% minor component), to lamellae (roughly equal component fractions) Most recently, there has been increasing interest in transformations between morphologies by thermal annealing. This paper describes initial results studying the effect of solvent evaporation rate and post-casting annealing treatment on the morphology of SBS thin films.TEM specimens were prepared by solution casting electron transparent films. 50 μl of 0.1 wt% SBS (30% styrene, Mw=14,000, Scientific Polymer Products, Inc.) dissolved in toluene was deposited on a polished NaCl single crystal substrate placed in a small dish. After solvent evaporation the film was cut into small squares, floated from the salt in water, and each square was collected on a Cu grid.

Glibenclamide-Nicotinamide Cocrystals Synthesized by The Solvent Evaporation Method to Enhance Solubility and Dissolution Rate of Glibenclamide

2019 ◽  
Vol 9 (01) ◽  
pp. 21-26
Author(s):  
Arif Budiman ◽  
Ayu Apriliani ◽  
Tazyinul Qoriah ◽  
Sandra Megantara
Keyword(s):  
Solvent Evaporation ◽  
Physical Mixture ◽  
Dissolution Profile ◽  
Solvent Evaporation Method ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Evaporation Method ◽  
Dissolution Properties ◽  
Mixture Characterization

Purpose: To develop glibenclamide-nicotinamide cocrystals with the solvent evaporation method and evaluate their solubility and dissolution properties. Methods: Cocrystals of glibenclamide-nicotinamide (1:2) were prepared with the solvent evaporation method. The prediction of interactive cocrystals was observed using in silico method. The solubility and dissolution were performed as evaluation of cocrystals. The cocrystals also were characterized by differential scanning calorimetry (DSC), infrared spectrophotometry, and powder X-ray diffraction (PXRD). Result: The solubility and dissolution profile of glibenclamide-nicotinamide cocrystal (1:2) increased significantly compared to pure glibenclamide as well as its physical mixture. Characterization of cocrystal glibenclamide-nicotinamide (1:2) including infrared Fourier transform, DSC, and PXRD, indicated the formation of a new solid crystal phase differing from glibenclamide and nicotinamide. Conclusion: The confirmation of cocrystal glibenclamide-nicotinamide (1:2) indicated the formation of new solid crystalline phases that differ from pure glibenclamide and its physical mixture

Preparation and Evaluation of Glipizide Tablets Containing both Enhanced and Sustained Release Solid Dispersions

1970 ◽  
Vol 2 (4) ◽  
pp. 714-725
Author(s):  
Adel M. Aly ◽  
Ahmed S. Ali
Keyword(s):  
Blood Glucose ◽  
Blood Glucose Level ◽  
Glucose Level ◽  
Solid Dispersions ◽  
Solvent Evaporation ◽  
In Vivo Studies ◽  
Solvent Evaporation Method ◽  
Evaporation Method ◽  
Tablet Formulations

: Glipizide (GZ) is an oral blood-glucose-lowering drug of the sulfonylurea class characterized by its poor aqueous solubility. Aiming for the production of GZ tablets with rapid onset of action followed by prolonged effect; GZ-Polyethylene glycol (PEG 4000 and 6000) solid dispersions with different ratios, (using melting and solvent evaporation method), as well as, coprecipitate containing GZ with polymethyl-methacrylate (PMMA) were prepared. Four tablet formulations were prepared containing; a) GZ alone, b) GZ: PEG6000, 1:10, c) GZ:PMMA 1:3, and, d)both GZ:PEG6000 1:10 and GZ:PMMA 1:3. The solvent evaporation method showed more enhancement of GZ solubility than the melting one, and this solubilizing effect increased with PEG increment. Generally, PEG6000 showed more enhancement of dissolution than PEG4000 especially at 1:10 drug: polymer ratio (the most enhancing formula). Also, the prepared tablet formulations showed acceptable physical properties according to USP/NF requirements. The dissolution results revealed that tablets containing PEG6000 (1:10) have the most rapid release rate, followed by the formula containing both PEG6000 and PMMA, while that including PMMA alone showed the slowest dissolution rate. Moreover, In-vivo studies for each of the above four formulations, were performed using four mice groups. The most effective formula in decreasing the blood glucose level, through the first 6 hours, was that containing GZ and PEG6000, 1:10. However, formula containing the combination of enhanced and sustained GZ was the most effective in decreasing the blood glucose level through 16 hours. Successful in-vitro in-vivo correlations could be detected between the percent released and the percent decreasing of blood glucose level after 0.5 hours.

Formulation Design and Optimization of Repaglinide Solid Dispersions by Central Composite Design

2018 ◽  
Vol 11 (6) ◽  
pp. 4337-4348
Author(s):  
Bhikshapathi D. V. R. N. ◽  
Srinivas I
Keyword(s):  
Central Composite Design ◽  
Dissolution Rate ◽  
Solid Dispersion ◽  
Solid Dispersions ◽  
Solvent Evaporation ◽  
Release Mechanism ◽  
Solvent Evaporation Method ◽  
Onset Of Action ◽  
Evaporation Method ◽  
Central Composite

Repaglinide is a pharmaceutical drug used for the treatment of type II diabetes mellitus, it is characterized with poor solubility which limits its absorption and dissolution rate and delays onset of action. In the present study, immediate release solid dispersion of repaglinide was formulated by solvent evaporation technique. Repaglinide solid dispersions were prepared using PEG 8000, Pluronic F 127 and Gelucire 44/14 by solvent evaporation method. A 3-factor, 3-level central composite design employed to study the effect of each independent variable on dependent variables. FTIR studies revealed that no drug excipient interaction takes place. From powder X-ray diffraction (p-XRD) and by scanning electron microscopy (SEM) studies it was evident that polymorphic form of repaglinide has been converted into an amorphous form from crystalline within the solid dispersion formulation. The correlation coefficient showed that the release profile followed Higuchi model anomalous behavior and hence release mechanism was indicative of diffusion. The obtained results suggested that developed solid dispersion by solvent evaporation method might be an efficacious approach for enhancing the solubility and dissolution rate of repaglinide.

CFD simulation of ultrasonic atomization pyrolysis reactor: the influence of droplet behaviors and solvent evaporation

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jian Wang ◽  
Jichuan Wu ◽  
Shouqi Yuan ◽  
Wei-Cheng Yan
Keyword(s):  
Flow Pattern ◽  
Size Distribution ◽  
Droplet Size ◽  
Cfd Simulation ◽  
Collection Efficiency ◽  
Great Influence ◽  
Droplet Size Distribution ◽  
Solvent Evaporation ◽  
Droplet Collision ◽  
Ultrasonic Atomization

Abstract Previous work showed that particle behaviors in ultrasonic atomization pyrolysis (UAP) reactor have a great influence on the transport and collection of particles. In this study, the effects of droplet behaviors (i.e. droplet collision and breakage) and solvent evaporation on the droplet size, flow field and collection efficiency during the preparation of ZnO particles by UAP were investigated. The collision, breakage and solvent evaporation conditions which affect the droplet size distribution and flow pattern were considered in CFD simulation based on Eulerian-Lagrangian method. The results showed that droplet collision and breakage would increase the droplet size, broaden the droplet size distribution and hinder the transport of droplets. Solvent evaporation obviously changed the flow pattern of droplets. In addition, both droplet behaviors and solvent evaporation reduced the collection efficiency. This study could provide detail information for better understanding the effect of droplet behaviors and solvent evaporation on the particle production process via UAP reactor.

scholarly journals Rosuvastatin cocrystals: an attempt to modulate physicochemical parameters

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Venkata Deepthi Vemuri ◽  
Srinivas Lankalapalli
Keyword(s):  
Physicochemical Properties ◽  
Dissolution Rate ◽  
Functional Groups ◽  
Preliminary Investigation ◽  
Scale Up ◽  
Solvent Evaporation ◽  
Molar Ratio ◽  
The Novel ◽  
Formulation Development ◽  
Hydrogen Bond Interaction

Abstract Background The meager physicochemical properties like low solubility and low dissolution rate of rosuvastatin calcium remain as an obstruction for formulation development. In the present work, we explore the evolution of rosuvastatin cocrystal, which may offer the synergetic physico-chemical properties of the drug. Cocrystal crafting depends on two possible intermolecular interactions; heteromeric and the homomeric selection of compounds with complementary functional groups are contemplated as a possible cause of supramolecular synthons in cocrystal formation. Specifically, cocrystals of rosuvastatin with l-asparagine and l-glutamine with molar ratio (1:1) were fabricated by using slow solvent evaporation and slow evaporation techniques. Novel cocrystals of rosuvastatin-asparagine (RSC-C) and rosuvastatin-glutamine (RSC-G) cocrystals obtained by slow solvent evaporation were utilized for preliminary investigation and further scale-up was done by using the solvent evaporation technique. Results The novel cocrystals showed a new characteristic of powder X-ray diffraction, thermograms of differential scanning calorimetry, 1H liquid FT-NMR spectra, and scanning electron microscopy. These results signify the establishment of intermolecular interaction within the cocrystals. In both the novel cocrystals, rosuvastatin was determined to be engaged in the hydrogen bond interaction with the complementary functional groups of l-asparagine and l-glutamine. Compared with the pure rosuvastatin, RSC-C and RSC-G cocrystal showed 2.17-fold and 1.60-fold improved solubility respectively. The dissolution test showed that the RSC-C and RSC-G cocrystal exhibited 1.97-fold and 1.94-fold higher dissolution rate than the pure rosuvastatin in pH6.8 phosphate buffer respectively. Conclusion Modulation in the chemical environment, improvement in the solubility, and dissolution rate demonstrated the benefit of co-crystallization to improve the physicochemical properties of the drug. Graphical abstract

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