Publications by authors named "Khawam A"

Currently, there is no test system, whether in vitro or in vivo, capable of examining all endpoints required for genotoxicity evaluation used in pre-clinical drug safety assessment. The objective of this study was to develop a model which could assess all the required endpoints and possesses robust human metabolic activity, that could be used in a streamlined, animal-free manner. Liver-on-chip (LOC) models have intrinsic human metabolic activity that mimics the in vivo environment, making it a preferred test system.

View Article and Find Full Text PDF

A theoretical model was previously derived to predict powder encapsulation in dosator-based machines. The theoretical basis of the model was discussed earlier. In this part; the model was evaluated experimentally using two powder formulations with substantially different flow behavior.

View Article and Find Full Text PDF

Automatic encapsulation machines have two dosing principles: dosing disc and dosator. Dosator-based machines compress the powder to plugs that are transferred into capsules. The encapsulation process in dosator-based capsule machines was modeled in this work.

View Article and Find Full Text PDF

Solvates are often encountered in pharmaceutical solids and knowledge of their physical stability is necessary for their effective formulation. This work investigates the solid-state stability of five structurally related solvates of sulfameter (5-methoxysulfadiazine) by studying the kinetics of their desolvation reaction with thermogravimetric analysis, both isothermally and nonisothermally. Desolvation kinetic analysis was done isothermally by conventional model-fitting and nonisothermally by the complementary method.

View Article and Find Full Text PDF

Many solid-state kinetic models have been developed in the past century. Some models were based on mechanistic grounds while others lacked theoretical justification and some were theoretically incorrect. Models currently used in solid-state kinetic studies are classified according to their mechanistic basis as nucleation, geometrical contraction, diffusion, and reaction order.

View Article and Find Full Text PDF

There are many methods for analyzing solid-state kinetic data. They are generally grouped into two categories, model-fitting and isoconversional (model-free) methods. Historically, model-fitting methods were widely used because of their ability to directly determine the kinetic triplet (i.

View Article and Find Full Text PDF

Most solid-state kinetic principles were derived from those for homogenous phases in the past century. Rate laws describing solid-state degradation are more complex than those in homogenous phases. Solid-state kinetic reactions can be mechanistically classified as nucleation, geometrical contraction, diffusion, and reaction order models.

View Article and Find Full Text PDF