Like many others, silicate solids dissolve when placed in contact with water. In a given aqueous environment, the dissolution rate depends on the composition and the structure of the solid and can span several orders of magnitude. Although the kinetics of dissolution depends on the complexities of both the dissolving solid and the solvent, a clear understanding of which structural descriptors o...

introduction the iran has vast areas of karst landforms due to the relatively high carbonaceous rocks deposited during different geologic eras. karst landforms are noteworthy for investigation from many aspects. the primary importance of these regions is the considerable amount of underground water stored in karst formations. these reserves are favorable, both in quality and quantity, as natura...

Efavirenz belongs to Class II under BCS and exhibit low and variable bioavailability due to its poor aqueous solubility. As such it needs enhancement in the dissolution rate and bioavailability to derive its maximum therapeutic efficacy. The objective of the present investigation is to study the complexation of efavirenz with two cyclodextrins, βcyclodextrin (βCD) and hydroxypropyl β-cyclodextr...

The model given in this report and the rotating disk method provide a useful combination in the study of dental enamel and hydroxyapatite dissolution kinetics. The present approach is a significant improvement over earlier studies, and both the ionic activity product that governs the dissolution reaction and the apparent surface dissolution reaction rate constant may be simultaneously obtained....

A quantitative understanding of the mechanism of human dental enamel dissolution in buffers is important because it should lead to a clear description of the causative factors in caries formation, and it can be profitably employed in the design of meaningful screening methods for potential anti-decay agents. Gray' has reported studies on enamel dissolution, concluding that the rates of dissolut...

 The physicochemical properties of the drug substance can assume a primary role in controlling its dissolution from the dosage form.  The aqueous solubility of the drug is one of the major factors that determine its dissolution rate.  Some studies concluded that the drug solubility data can be used as rough predictor of the possibility of any future problems with bioavailability.  Some of t...

The rate of reaction of hematite with quinones and the quinone moieties of larger molecules may be an important factor in limiting the rate of reductive dissolution of hematite, especially by iron-reducing bacteria. It is possible that the rate of reductive dissolution of hematite in the presence of excess hydroquinone at pH 2.5 may be limited by the electron-transfer rate. Here, a reductive di...

Surface solid dispersions using water-insoluble carriers like crospovidone, croscarmellose sodium, sodium starch glycolate, pre-gelatinized starch, potato starch and Avicel PH 101 were investigated to enhance the dissolution rate of the glimepiride, a poorly water insoluble drug. The effect of various carriers on dissolution profile was studied using presence absence model. The surface solid di...

Mathematical models play an essential role in simulation of dynamic processes as they provide insights into the description and behaviour of real systems. Models of chemical processes are derived from laws of conservation, thermodynamic, and control design. In the present paper, we study the modelling of dissolution process determining the quasi steady state material balance for velocity profil...

Poorly water soluble molecules are typically formulated for improving their dissolution rate and storage stability by increasing active drug surface area that come in the contact with the dissolution medium [4]. Most important characteristics of nanosuspensions are their exhibited particle size; polydispersity index, drug saturation solubility, physical stability, dissolution rate and bioavaila...