Polymorphism

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Presentation Transcript

Slide 1: 

By, Mr. Nitin M. Kadam [email protected]

CONTENTS : 

CONTENTS Definition , Introduction Different Shapes Applications to Pharmacy Detection Techniques [Mention] Glass Transition Temperature & Thermodynamics involved

INTRODUCTION : 

INTRODUCTION Definition: It is the ability to any compound or element to crystallize as one or more distinct crystal species with different internal lattice.

INTRODUCTION : 

Particular Packing Definite Energy value Temperature Transition Temperature INTRODUCTION

Slide 5: 

Classification Of Polymorphs Enantiotropic Reversible change Affected by temp. moisture and grinding Monotropic (Metastable) No reversible change Not affected by temp. moisture and grinding Dynamic Allotropy Reversible change

Factor Influencing Polymorphism : 

Temperature Pressure Solvents Agitation Milling Rate of Crystallization Factor Influencing Polymorphism

Shapes of Polymorphs : 

Shapes of Polymorphs Shapes of Polymorphs: Rectangle, Line, Oval.

Physicochemical Parameters That Alter : 

Physicochemical Parameters That Alter Melting point Density Hardness Crystal shape Optical properties Vapor pressure

Parameters That Alter : 

Changes in chemical stability and solubility Effects drug’s bioavailability and its development program Parameters That Alter

Methods To Identify Polymorphism : 

Methods To Identify Polymorphism Microscopy Hot stage method Microscopy Dissolution X-ray powder diffraction IR NMR Thermal analysis[ DSC, DTA, TGA ] Dilatometry X-ray crystallography

Drugs Screened By This Method. : 

Phenobarbiton-13 Cemetidine-7 Sertraline-17polymorphs;4solvates;6hydrates and 1amorphous. Excipients:-mannitol-4;aspartame-5 Drugs Screened By This Method.

Applications To Pharmacy : 

Applications To Pharmacy High Dissolution rate. Time of conversion Suspensions Compaction Bioavailability Reproducible results Crystal transitions from milling, WG., changes physical & biological properties of DF. Stable form destroyed due to high temp. e.g. Suppositories. Metastable to stable– Crystalline out– appearance, texture changes. E.g. Creams

Thermodynamics and Polymorphism : 

Thermodynamics and Polymorphism It was said earlier that crystal nucleation and growth are quite often under kinetic control. The final product, the (single) crystal, may result from less stable but faster growing nuclei; the forces holding together the metastable phase have to be overcome to transformation to the thermodynamically stable phase, because so that molecules can rearrange into the stable crystalline form. In some favorable (and almost exceptional) cases, the spatial rearrangement is so simple that a highly cooperative single crystal to single crystal transformation can occur. The natural outcome of all this is polymorphism, or the ability of a given compound to crystallize in different forms. Thermodynamics holds that only one form is the stable one at a given temperature and pressure.

Slide 14: 

“You were born to win, but to be a winner you must plan to win, prepare to win, and expect to win.”

Slide 15: 

THANK YOU

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