Newtonian and non newtonian flow

Power Point Presentation

1. S.M.B.T COLLEGE OF PHARMACY DHAMANGAON, NASHIK Newtonian and Non-Newtonian flow Presented by: Ms. Suvarna Shelke Assistant Professor, Pharmaceutics Dept.

2. lecture outcomes After completion of this topic students will be able to- Explain Newtonian flow and Newtonian flow Differentiate between various types of flow 2

3. Contents Introduction Newtonian flow Non- Newtonian flow and its types Summery 3

4. Introduction 4 Rheology is the science that concerns with the flow of liquids and the deformation of solids . Study of flow properties of liquids is important for pharmacist working in the manufacture of several dosage forms, viz., simple liquids, gels, ointments, creams, and pastes. Types of flow : Newtonian and Non-Newtonian systems . These systems changes their flow behavior when exposed to different stress conditions

5. Newtonian flow 5 Newtonian Flow Liquids that obey Newton’s law of flow are called as Newtonian fluids. Newton’s equation for the flow of liquids: F=ηG Examples: Water Glycerin Chloroform

6. Non-Newtonian flow 6 Non- Newtonian Flow Non - Newtonian systems are those substances, which fail to follow Newton's law. Examples: Emulsions, suspensions and semisolids. They are classified into 3 types of flow : 1) Plastic flow 2) Pseudoplastic flow 3) Dilatant flow

7. Plastic Flow 07-07-2021 7 The plastic flow curve does not pass through the origin. Material exhibit plastic flow are called Bingham bodies. The equation describing plastic flow is, U=F-f/G Examples: Flocculated particles in concentrated suspension, ointments

8. Pseudoplastic Flow 07-07-2021 8 The consistency curve for a pseudoplastic material begins at the origin. As the shear stress increases progressively , shear rate also increases, but trend is not linear. Also called “ Shear thinning system ”. Examples: Tragacanth in water, Sodium alginate in water, Methyl cellulose in water

9. Dilatant Flow 07-07-2021 9 These system exhibit increase in resistance to flow with increasing rates of shear. Dilatant materials also called “ Shear thickening systems .“ Examples- Suspension of starch in water, Certain suspensions with high concentration (50 > %) of small, deflocculated particles.

10. Rheograms of different fluids 10

11. Summery 11 In order to be manufactured dosage forms, need specific flow properties so they can be placed into a container, remain stable over time, dispensed and handled properly. The pouring of the liquids from containers, extrusion of ointment from tubes, proper application of product to the affected area by patients these all are depend on the changes in flow behavior of dosage forms.