Bubble-induced fast crystal growth of indomethacin polymorphs in a supercooled liquid

2021 ◽  
Vol 54 (5) ◽  
Author(s):  
Qin Shi ◽  
Fang Li ◽  
Jia Xu ◽  
Lingling Wu ◽  
Junbo Xin ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Physical Stability ◽  
Pharmaceutical Formulations ◽  
Supercooled Liquid ◽  
Pharmaceutical Solids ◽  
Liquid Bubble ◽  
Different Temperatures ◽  
Surface Crystal

Physical stability is one of the main challenges when developing robust amorphous pharmaceutical formulations. This article reports fast crystal growth behaviors of the γ and α forms of indomethacin (IMC) initiated by bubbles in the interior of a supercooled liquid. Bubble-induced crystal growth of γ-IMC exhibits approximately the same kinetics as its surface crystal growth, supporting the view that bubble-induced crystal growth is a surface-facilitated process. In contrast, the rates of bubble-induced crystal growth of α-IMC are much faster than those of its surface crystal growth. These results indicate that the bubble-induced crystal growth not only depends on the interface created by the bubble but also strongly correlates with the true cavitation of the bubble. Moreover, bubble-induced fast crystal growth of γ- and α-IMC can be terminated at different temperatures by cooling. These outcomes are meaningful for the in-depth understanding of physical stability and pre-formulation study of amorphous pharmaceutical solids showing surface-facilitated crystal growth.

Biosurfactants as a Novel Additive in Pharmaceutical Formulations: Current Trends and Future Implications

2020 ◽  
Vol 21 (11) ◽  
pp. 885-901
Author(s):  
Shubham Thakur ◽  
Amrinder Singh ◽  
Ritika Sharma ◽  
Rohan Aurora ◽  
Subheet Kumar Jain
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Toxicity Testing ◽  
Pharmaceutical Formulations ◽  
Delivery Systems ◽  
Surface Active Agents ◽  
Regulatory Status ◽  
Different Temperatures ◽  
High Production Cost ◽  
New Generation

Background: Surfactants are an important category of additives that are used widely in most of the formulations as solubilizers, stabilizers, and emulsifiers. Current drug delivery systems comprise of numerous synthetic surfactants (such as Cremophor EL, polysorbate 80, Transcutol-P), which are associated with several side effects though used in many formulations. Therefore, to attenuate the problems associated with conventional surfactants, a new generation of surface-active agents is obtained from the metabolites of fungi, yeast, and bacteria, which are termed as biosurfactants. Objectives: In this article, we critically analyze the different types of biosurfactants, their origin along with their chemical and physical properties, advantages, drawbacks, regulatory status, and detailed pharmaceutical applications. Methods: 243 papers were reviewed and included in this review. Results: Briefly, Biosurfactants are classified as glycolipids, rhamnolipids, sophorolipids, trehalolipids, surfactin, lipopeptides & lipoproteins, lichenysin, fatty acids, phospholipids, and polymeric biosurfactants. These are amphiphilic biomolecules with lipophilic and hydrophilic ends and are used as drug delivery vehicles (foaming, solubilizer, detergent, and emulsifier) in the pharmaceutical industry. Despite additives, they have some biological activity as well (anti-cancer, anti-viral, anti-microbial, P-gp inhibition, etc.). These biomolecules possess better safety profiles and are biocompatible, biodegradable, and specific at different temperatures. Conclusion: Biosurfactants exhibit good biomedicine and additive properties that can be used in developing novel drug delivery systems. However, more research should be driven due to the lack of comprehensive toxicity testing and high production cost which limits their use.

scholarly journals Crystal growth of the core and rotated epitaxial shell of a heterometallic metal-organic framework revealed with atomic force microscopy

2021 ◽  
Author(s):  
Fajar Inggit Pambudi ◽  
Michael William Anderson ◽  
Martin Attfield
Keyword(s):  
Atomic Force Microscopy ◽  
Crystal Growth ◽  
Metal Organic Framework ◽  
Metal Organic Frameworks ◽  
Force Microscopy ◽  
The Core ◽  
Atomic Force ◽  
Metal Organic ◽  
Surface Crystal ◽  
Organic Framework

Atomic force microscopy has been used to determine the surface crystal growth of two isostructural metal-organic frameworks, [Zn2(ndc)2(dabco)] (ndc = 1,4-naphthalene dicarboxylate, dabco = 4-diazabicyclo[2.2.2]octane) (1) and [Cu2(ndc)2(dabco)] (2) from...

scholarly journals Stability of Amorphous Pharmaceutical Solids: Crystal Growth Mechanisms and Effect of Polymer Additives

2012 ◽  
Vol 14 (3) ◽  
pp. 380-388 ◽  
Author(s):  
Ye Sun ◽  
Lei Zhu ◽  
Tian Wu ◽  
Ting Cai ◽  
Erica M. Gunn ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Polymer Additives ◽  
Growth Mechanisms ◽  
Pharmaceutical Solids

A Simple Method for Estimating the Extent of Surface Crystal Development on Colored Cheddar Cheese

1986 ◽  
Vol 49 (6) ◽  
pp. 421-422 ◽  
Author(s):  
STEPHEN T. DYBING ◽  
STEVEN A. BRUDVIG ◽  
JAMES A. WIEGAND ◽  
EMIL A. HUANG
Keyword(s):  
Crystal Growth ◽  
Shelf Life ◽  
Environmental Conditions ◽  
Cheddar Cheese ◽  
Simple Method ◽  
Flat Surfaces ◽  
White Cheese ◽  
Shelf Life Studies ◽  
Non Destructive ◽  
Surface Crystal

A simple, non-destructive method for estimating the extent of crystal development as white specks on the surface of colored Cheddar cheese is described. This method involves photocopying the surface of the cheese with a photocopier set at an exposure calibrated to clearly show the crystals. The photocopies of the cheese surface are then compared to a series of photocopies showing designated increases in crystal growth. Crystal development was rated as follows: 0 = no crystals, 1= light, 2 = medium, 3 = heavy, and 4 = very heavy to encrusted crystal development. The method does not disrupt or destroy the environmental conditions existing in the cheese package, allowing extended shelf life studies to be done on the same piece of cheese. However, the photocopy technique may not work as well with white cheese or cheeses without flat surfaces.

scholarly journals Chemical Solution Deposition of BaxSr1-xTiO3 Thin Films for Energy Storage Applications

Proceedings ◽  
2020 ◽  
Vol 56 (1) ◽  
pp. 9
Author(s):  
Federica Benes ◽  
Mirela Dragomir ◽  
Barbara Malič ◽  
Marco Deluca
Keyword(s):  
Thin Films ◽  
Crystal Growth ◽  
Chemical Solution Deposition ◽  
Annealing Temperature ◽  
Chemical Solution ◽  
Solution Deposition ◽  
Annealing Conditions ◽  
Different Temperatures ◽  
Energy Storage Applications ◽  
Xrd Techniques

Highly textured Ba0.5Sr0.5TiO3 and Ba0.6Sr0.4TiO3 thin films have been successfully processed using chemical solution deposition (CSD) techniques and annealed at different temperatures to investigate the influence on crystal growth. Microstructure and texture have been evaluated using SEM and XRD techniques. The films showed a homogeneous thickness of ~120 nm and the grain growth seemed to be highly influenced by the annealing temperature. Moreover, by tuning the deposition and annealing conditions, an almost epitaxial growth of Ba0.6Sr0.4TiO3 on the platinized silicon substrate has been achieved. Nevertheless, the samples showed severe cracking due to the strain imposed by the substrate or due to the growing direction.

scholarly journals Kinetic Processes in Amorphous Materials Revealed by Thermal Analysis: Application to Glassy Selenium

Molecules ◽  
2019 ◽  
Vol 24 (15) ◽  
pp. 2725 ◽  
Author(s):  
Málek ◽  
Svoboda
Keyword(s):  
Activation Energy ◽  
Crystal Growth ◽  
Viscous Flow ◽  
Structural Relaxation ◽  
Amorphous Materials ◽  
Supercooled Liquid ◽  
Thermomechanical Analysis ◽  
Growth Data ◽  
Scanning Calorimetry ◽  
Kinetic Processes

It is expected that viscous flow is affecting the kinetic processes in a supercooled liquid, such as the structural relaxation and the crystallization kinetics. These processes significantly influence the behavior of glass being prepared by quenching. In this paper, the activation energy of viscous flow is discussed with respect to the activation energy of crystal growth and the structural relaxation of glassy selenium. Differential scanning calorimetry (DSC), thermomechanical analysis (TMA) and hot-stage infrared microscopy were used. It is shown that the activation energy of structural relaxation corresponds to that of the viscous flow at the lowest value of the glass transition temperature obtained within the commonly achievable time scale. The temperature-dependent activation energy of crystal growth, data obtained by isothermal and non-isothermal DSC and TMA experiments, as well as direct microscopic measurements, follows nearly the same dependence as the activation energy of viscous flow, taking into account viscosity and crystal growth rate decoupling due to the departure from Stokes–Einstein behavior.

Effect of Phosphate and Silica on the Rate of Crystallization of Sucrose

2005 ◽  
Vol 1 (5) ◽  
Author(s):  
Ms. Aamarpali Ratna Puri ◽  
S. Kaur
Keyword(s):  
Growth Rate ◽  
Crystal Growth ◽  
Mother Liquor ◽  
Crystal Surface ◽  
Mass Transfer Process ◽  
Sugar Solution ◽  
Local Conditions ◽  
Concentration Difference ◽  
Different Temperatures ◽  
Sucrose Crystals

Sucrose Crystallization is a mass transfer process. Sucrose molecule's migration from solution to crystal is driven by concentration difference between the mother liquor and the crystal surface; the coefficient of super saturation is the most important parameter for the process. Supersaturation of sugar solution depends on the purity and brix of the mother liquor. It has large influence on product's quantity and quality (crystal yield, crystal size and size distribution) and on the cost of production i.e output/hour and energy consumption. However there is still no generally applicable theory, which permits an accurate prediction of the effects of all the factors that govern the industrial processes of crystallization from solution. The crystal growth depends on the viscosity, which further depends on the nature and amount of impurities. If the local conditions are favourable, localized layers of molecules of impurity can statistically remain on the surface for a period of time. On the other hand, if the interaction between the impurity and the layer is weak, then there will be competition between impurity and sucrose molecules thus affecting the sucrose crystal growth rate. In the present study, the growth rate of sugar crystals was studied, using two-litre automatic laboratory vacuum pan, under controlled conditions in the presence of impurities. The effect of phosphate and silica (adding one at time) on the growth rate of sugar crystals was studied at two different temperatures 328 and 338K and with two different seed sizes of sucrose (850 and 600µm). The growth rate was studied at two degrees of supersaturation (1.10 and 1.15). The growth rate of sucrose crystals (with or without added impurities) showed significant increase with the 10°C rise in temperature. The growth rate of sucrose crystals increased with the increase in the level of phosphate but decreased with the increase in the level of silica in sugar solution.

Crystallization of Organic Glasses: How Does Liquid Flow Damage Surface Crystal Growth?

2016 ◽  
Vol 16 (5) ◽  
pp. 2931-2936 ◽  
Author(s):  
Daniele Musumeci ◽  
Mariko Hasebe ◽  
Lian Yu
Keyword(s):  
Crystal Growth ◽  
Liquid Flow ◽  
Organic Glasses ◽  
Surface Crystal
Sign in / Sign up

Export Citation Format

Share Document