Preservatives: If these materials prevent the initiation and growth of microorganisms in products, they are known as bactericidal preservatives. Some preservatives, either by concentration or activity, may only maintain the bacteria level in the product at the time of manufacture […]
Principle The ball mill operates on the principle of impact and attrition. In this, impact occurs between fast moving balls and the powder material while the attrition mode comes in action when the hollow cylinder rotates on its longitudinal axis. […]
Rotary Cutter Mill Principle In Rotary cutter mill, feed material is size reduced by continuous cutting and shearing by the help of sharp knives Construction In this mill, the milling chamber contains 2 types of knives: stationary knives and rotating […]
Principle The hammer mill works on the principle of impact. Here impact occurs between the fast moving hammers which are fitted on a rotor and the feed material. Construction The hammer mill is of two types: either vertically shafted type […]
When powders are poured into a pile, segregation occurs. Particles with small size (fine particles) will stay in the center of the pile, and coarser particles tend to concentrate at the periphery. Size segregation is unavoidable, during powder transportation, storage, […]
The term “powder” has more than one connotation in pharmacy. It may be used to describe the physical form of a material, that is, a dry substance composed of finely divided particles. Or, it may be used to describe a […]
Diffusion During Swelling of Matrix – When water-soluble drugs are entrapped in glassy hydrogels, the release of the drugs engages simultaneously the absorption of water and desorption of drug while the hydrogels swell slowly. Drug release kinetics is governed by […]
DRUG RELEASE FROM POLYMER MATRICES: When the conventional dosage forms (i.e. tablets, capsules, ointment or creams) are administered orally or topically, the active drug in the dosage form is immediately released and absorbed into the systemic circulation. The release of […]
APPLICATIONS OF DIFFUSION PRINCIPLES: Drug Absorption by Passive Diffusion – Passive diffusion is the major trans-membrane transport process for most drugs. The driving force for passive diffusion is the difference in drug concentrations on either side of the cell membrane. […]