Studies on Glass. II. The Transition between the Glassy and Liquid States in the Case of Glucose

“…As already reported, due to recrystallization (physical instability) during dissolution, it is challenging to quantify the practical solubility of amorphous materials experimentally (37), therefore, a model developed by Parks et al (38,39) may be used to predict the relative solubility of the amorphous and crystalline forms of material based on the difference in their free energy (ΔG) as per the below equation.…”

Section: Estimation Of Apparent Solubilitymentioning

confidence: 99%

Wetting Kinetics: an Alternative Approach Towards Understanding the Enhanced Dissolution Rate for Amorphous Solid Dispersion of a Poorly Soluble Drug

Verma

Rudraraju²

2015

AAPS PharmSciTech

View full text Add to dashboard Cite

Abstract. Developing amorphous solid dispersions of water-insoluble molecules using polymeric materials is a well-defined approach to improve the dissolution rate and bioavailability. While the selected polymer plays a vital role in stabilizing the amorphous solid dispersion physically, it is equally important to improve the dissolution profile by inhibiting crystallization from the supersaturated solution generated by dissolution of the amorphous material. Furthermore, understanding the mechanism of dissolution rate enhancement is of vital importance. In this work, wetting kinetics was taken up as an alternative approach for understanding the enhanced dissolution rate for amorphous solid dispersion of a poorly soluble drug. While cilostazol (CIL) was selected as the model drug, povidone (PVP), copovidone, and hypromellose (HPMC) were the polymers of choice. The concentrations against time profiles were evaluated for the supersaturated solutions of CIL in the presence and absence of the selected polymers. The degree of supersaturation increased significantly with increase in polymer content within the solid dispersion. While povidone was found to maintain the highest level of supersaturation for the greatest length of time both in dissolution and solution crystallization experiments, copovidone and hypromellose were found to be the less effective as crystallization inhibitor. The ability of polymers to generate and maintain supersaturated drug solutions was assessed by dissolution studies. The wetting kinetics was compared against the solid dispersion composition to establish a correlation with enhanced dissolution rate.

show abstract

“…The structure determination is available only in the case of glucose. 13 Most available data are macroscopic, such as thermal expansivity, 14 density, 14 viscosity, 15,16 fragility, 17 and diffusion constants of small traces of water. 18 The temperature dependent dielectric response has been also investigated so that some information on the size relaxation processes is now available.…”

Section: Introductionmentioning

confidence: 99%

Neutron scattering investigation of high-frequency dynamics in glassy glucose

et al. 2012

View full text Add to dashboard Cite

The vibrational dynamics of vitreous glucose has been investigated by means of inelastic neutron scattering experiments, exploiting the coherent scattering cross section of deuterium in a fully deuterated sample and the high incoherent scattering cross section of hydrogen in a hydrogenated sample. The first part of the experiment allowed a rather detailed investigation of the collective dynamics in the THz range. The second part of the experiment was used to derive some information on the vibrational density of states of the system. The experiment confirms the presence of a propagating vibrational mode which is the natural extension at THz frequencies of the lower frequencies longitudinal sound mode. In addition, a second mode is also observed at a lower and almost constant frequency, showing an increasing intensity on reducing the wavelength. By comparing the dispersion relations of these collective modes to the experimental density of states, a possible relation between the low frequency mode and the well known excess of low frequency modes, that is, the boson peak, is identified.

show abstract

Studies on Glass. II. The Transition between the Glassy and Liquid States in the Case of Glucose

Cited by 85 publications

References 0 publications

Effect of polymer type on the dissolution profile of amorphous solid dispersions containing felodipine

Effect of polymer type on the dissolution profile of amorphous solid dispersions containing felodipine

Wetting Kinetics: an Alternative Approach Towards Understanding the Enhanced Dissolution Rate for Amorphous Solid Dispersion of a Poorly Soluble Drug

Neutron scattering investigation of high-frequency dynamics in glassy glucose

Contact Info

Product

Resources

About