Which is pH sensitive polymer?
Although many sources talk about synthetic pH sensitive polymers, natural polymers can also display pH-responsive behavior. Examples include chitosan, hyaluronic acid, alginic acid (link to Wiki article: Alginic acid) and dextran. Chitosan, a frequently used example, is cationic.
How do pH sensitive hydrogels work?
A pH-sensitive hydrogel is a gel structure that is sensitive to changes in pH. These pH-sensitive hydrogels have applications in forming valves that are sensitive to a change in pH or in systems that can release a compound when the pH is changed and in pH sensors.
What are polymers sensitive to?
Such materials can be sensitive to a number of factors, such as temperature, humidity, pH, chemical compounds, the wavelength or intensity of light or an electrical or magnetic field and can respond in various ways, like altering colour or transparency, becoming conductive or permeable to water or changing shape (shape …
Which polymer are ion sensitive in nature?
Polymers exhibiting lower critical solution temperature (LCST) transitions can be used as ion-sensitive DDS. LCST transitions have been observed in aqueous solution of several polymers, such as poly(N-isopropylacrylamide) (PNI-PAM) [102], cellulose derivatives [103], poly(vinyl ether), poly (N-vinyl caprolactam) [104].
Which of the following is a pH sensitive biodegradable polymer?
Among these specific synthetic polymers, derivatives of polypeptides such as poly(l-glutamic acid) (PGA), poly(histidine) (PHIS), and poly(aspartic acid) (PASA) are biocompatible, degradable pH-sensitive polymers.
Are plants and animals pH sensitive?
All plants and animals are sensitive towards pH. Living organism works within the narrow range of pH. Our body also works within the narrow range of pH of 7.0 to 7.8 only. If this pH range increases or decreases, living organism find it difficult to survive.
What are thermosensitive hydrogels?
Thermosensitive hydrogels are very important biomaterials used in drug delivery systems (DDSs), which gained increasing attention of researchers. By in vivo injection, the hydrogels formed non-flowing gel at body temperature.
What are the disadvantages of smart polymers?
In spite of these advantages several drawbacks associated with these systems include high-burst drug release, low mechanical strength of the gel leading to potential dose-dumping, lack of biocompatibility of the polymeric system and gradual lowering of pH of the system due to acidic degradation14, 15.
What is the normal pH of gastric fluid?
The normal volume of the stomach fluid is 20 to 100 mL and the pH is acidic (1.5 to 3.5). These numbers are converted to actual acid production in units of milliequivalents per hour (mEq/hr) in some cases.
Which is the most sensitive pH sensitive polymer?
The most commonly used pH-sensitive polymers are derivatives of acrylic acid and cellulose. By combining the knowledge of polymers and their solubility at different pH environments, delivery systems have been designed to deliver drugs at the target site.
How are pH sensitive polymers used in drug delivery?
pH-sensitive gels: Many polyanionic materials, such as poly (acrylic acid), are pH sensitive and the degree of swelling of such polymers can be modulated by changing the pH. An application of such technology has been in the development of biomimetic secretory granules for drug delivery applications.
Why are drug release rates sensitive to pH?
The charge density of the polymers depends on pH and ionic composition of the outer solution (the solution into which the polymer is exposed). Altering the pH of the solution will cause swelling or deswelling of the polymer. Thus, drug release from devices made from these polymers will display release rates that are pH sensitive.
How are ion sensitive polymers used in medicine?
As ion-sensitive polymers, ion-exchange resins are frequently used for taste-masking, counterion-responsive drug release and sustained drug release. Polymers responding to ions in the saliva and gastrointestinal fluids are also used for controlled drug release in oral drug formulations.