Pharmaceutical Materials for Smart Use

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Questions and Answers

What is the primary focus of the topic 'SMART MATERIALS FOR PHARMACEUTICAL USE'?

Designing novel materials for pharmaceutical applications (correct)

Development of new pharmaceuticals

Understanding human physiology

Improving medical devices

What is the main characteristic of 'smart materials'?

Always toxic

Responsive to external stimuli (correct)

Static in nature

Only applicable in pharmaceuticals

What type of responsive materials is being discussed in topic 6?

Light responsive

pH and/or ion responsive (correct)

Temperature responsive

Glucose responsive

What is depicted in the schematic illustration?

pH levels in the gastrointestinal tract Signup and view all the answers

What is the description of 'dendrimers'?

Repetitively branched molecules Signup and view all the answers

What is the title of the journal mentioned?

Journal of Controlled Release Signup and view all the answers

What is the environment depicted at the cellular level?

In a prototypical mammalian cell Signup and view all the answers

What is the location of the schematic illustration of pH levels?

In the colon Signup and view all the answers

What is the typical shape of a dendrimer?

Spherical Signup and view all the answers

What is the origin of the name 'dendrimer'?

Greek word for 'tree' Signup and view all the answers

What happens to the ionizable groups in polymers when the environmental pH changes?

Their degree of ionization is altered Signup and view all the answers

What is the effect of ionic repulsion on polymeric chains?

It causes them to repel each other Signup and view all the answers

What is the purpose of conjugation chemistry with pH-labile chemical bonds?

To trigger drug release following a decrease in pH Signup and view all the answers

What is the result of osmotic pressure effects by the mobile counter ions?

An increase in the hydrodynamic volume Signup and view all the answers

What happens to weak polyacids at neutral and high pH?

They are deprotonated and expose charges Signup and view all the answers

What type of polymers will gain charge in acidic conditions?

Polybases Signup and view all the answers

What is the molar ratio of MAPTAC to AAc in the hydrogel?

10 mol MAPTAC / 20 mol AAc Signup and view all the answers

What type of hydrogels are described in the text?

Polyampholyte hydrogels Signup and view all the answers

What is the purpose of polymers with ionizable groups in pharmaceutical applications?

To create pH-dependent charge Signup and view all the answers

What is the name of the molecule shown in the figure?

Metakilamido)propil]trimetil-Amonyum klorür Signup and view all the answers

What is the pH range at which polybases gain charge?

Acidic conditions Signup and view all the answers

What type of materials are polyampholyte hydrogels used as?

Pharmaceutical materials Signup and view all the answers

Study Notes

pH and/or Ion Responsive Materials

pH levels in the body vary, with the colon having a pH of around 5.5-6.8, and the gastrointestinal tract having a pH range of 1.5-7.4.
Dendrimers are repetitively branched molecules that can be used to trigger drug release following a decrease in pH.
There are two major approaches to trigger drug release using pH responsive materials:
- Ionizable groups that introduce structural changes or destabilization in self-assembled vesicles.
- Conjugation chemistry with pH-labile chemical bonds between the drug and the constituent polymers or in between polymer components that entrap the drug.

Polymers with Ionizable Groups

Polymers with ionizable groups in their backbone can form polyelectrolytes in aqueous media.
Ionization of these groups changes with environmental pH changes, altering the degree of hydrodynamic volume and ionic repulsion of the polymeric chains.
Osmotic pressure effects occur due to the mobile counter ions.

Polyampholyte Hydrogels

Polyampholyte hydrogels are formed using MAPTAC and AAc.
The pH responsiveness of these hydrogels is dependent on the degree of ionization of the polyampholyte chains.
At low pH, the polyampholyte chains are positively charged, while at high pH, they are negatively charged.
Polyampholyte hydrogels can be used to create pH-responsive materials for pharmaceutical applications.

pH Responsiveness of Polyampholyte Hydrogels

Weak polyacids are deprotonated and expose charges at neutral and high pH, while polybases gain charge when shifting to acidic conditions.
The pH responsiveness of polyampholyte hydrogels can be controlled by altering the composition of the polyampholyte chains.