What is polymorphism in Preformulation?
What is polymorphism in Preformulation?
The term polymorphism was coined by AGUIAR ETAL in 1967. THUS IT IS DEFINED AS THE ABILITY OF SUBSTANCE TO EXIST AS TWO OR MORE CRYSTALLINE PHASES THAT HAVE DIFFERENT ARRRANGEMENTS OR CONFIRMATIONS OF THE MOLECULES IN THE CRYSTAL LATTICE.
What are examples of polymorphs?
Some common examples of polymorphs are calcite and aragonite. The composition of these two minerals is CaCO3, but calcite is rhombohedral while aragonite is orthorhombic. Diamond and graphite , both of which are pure carbon , are also polymorphs.
How does polymorphism affect drug properties?
Results: Due to the differences in internal crystalline structure, different polymorphs of the same solid drugs generally show different physicochemical properties, including powder property, melting point, enthalpy of fusion, dissolution behavior and stability.
What contributes to drug polymorphism?
Drug polymorphism: Same Drug, Different Response. That patients’ age, gender, size, and body composition influence their responses to a drug is common knowledge. Such variation in response is called drug polymorphism.
Why are polymorphs important?
Furthermore, polymorphism in drugs can affect such physicochemical properties as dissolution rate, solubility, bioavailability and manufacturability (Brittain, 2007). The detection of polymorphs in the drug discovery and manufacturing process is thus very important for quality control and assurance.
Which drugs show polymorphism?
The most important properties during drug discovery and development include solubility, dissolution, bioavailability, and physical/chemical stability. The best known polymorphs showing a significantly different bioavailability in human study are chloramphenicol palmitate [5] and mefenamic acid [6].
What are polymorphs in medicine?
polymorph. The common abbreviated term for polymorphonuclear (many-shaped nucleus) neutrophil leukocyte, the small phagocytic white cell of the immune system present in enormous numbers in the blood and the tissues.
How does polymorphism affect bioavailability?
Due to the differences in crystal structure, different polymorphs of a given solid drug show different physicochemical characteristics, which may lead to different drug bioavailability and half-life of the drug.
Where is medication metabolized?
Most drugs must pass through the liver, which is the primary site for drug metabolism. Once in the liver, enzymes convert prodrugs to active metabolites or convert active drugs to inactive forms. The liver’s primary mechanism for metabolizing drugs is via a specific group of cytochrome P-450 enzymes.
How do polymorphs differ?
According to Ostwald’s rule, usually less stable polymorphs crystallize before the stable form. Most polymorphs of organic molecules only differ by a few kJ/mol in lattice energy. Approximately 50% of known polymorph pairs differ by less than 2 kJ/mol and stability differences of more than 10 kJ/mol are rare.
What are polymorphic bacteria?
Polymorphic bacteria, varying at single loci, become probes for our uncovering important cellular and immunologic processes in the host. In summary, everything present in humans has been discovered by bacteria long ago, either as our ancestors or as our cohabitors or parasites.
What is polymorphs blood test?
any of a group of white blood cells that have lobed nuclei and granular cytoplasm and function as phagocytes; they include neutrophils, basophils, and eosinophils.
