Recent content by jtdrexel

The compressive stress during tablet compaction is typically on the order of 200 to 500MPa. There is definitely failure and hence the separation of part of the tablet however i am not sure about fatigue. Drug crystals can have slip systems and can cleave along slip planes. But there is no true...

The punch coating is a great idea! punch manufacturers are actively working to come up with coatings that would mitigate sticking. However, this is still a shoot in the dark approach. A particular coating may work for one compound and not another. Teflon has been used but is not too common or...

This is a great idea! Not sure how effectively it would work, but to my knowledge this has not been tested. Thank you for sharing your thoughts.

This is actually something that has been attempted. For example, folks have tried to use a spray system that will spray solid lubricant (like magnesium stearate) on the punch surface prior to compaction. It essentially acts as a 'release agent' in this scenario. Spraying a solid lubricant may...

Pharmaceutical tablets are formed by compressing powder in a die by metal punches until a compact is formed. The term ‘Sticking’ refers to a phenomenon that results in the adherence of material onto the punch faces and die wall even after the metal has left contact with the tablet. I am...

My name is James. I joined this site earlier this year when i learned of the strong scientific community here. I have many science questions to ask and i am almost never satisfied until i can get a true understanding of something. I work in pharma as a scientist specializing in material science...

Why would velocity perpendicular to flow be unchanged? My simple thought would be that there would be a preference in trajectory for molecules in a flow situation to be aligned more along the direction of flow. The only rigid surfaces in flow are perpendicular to the direction of flow.

@Chestermiller: Villa asked if it made sense that "if velocity of liquid molecules increases then they will have less time to collide with the walls and so pressure decreases ". And you said It doesn't seem logical in any sense. Why not? I would think that in static a condition like a sealed box...