Which polymer is used for in situ gel forming system?
Various polymers that are used for the formulation of in situ gels include gellan gum, alginic acid, xyloglucan, pectin, chitosan, poly(DL-lactic acid), poly(DL-lactide-co-glycolide) and poly-caprolactone.
What is in situ gel formation?
In situ is a Latin phrase which can be translated literally as “In process.” In situ gels are drug delivery systems that are in solution forms before administration in the body, once administered they undergo gelation in situ to form a gel. It is basically a polymeric drug delivery system.
What is in situ gelation?
In situ gelling systems are polymeric formulations that are in sol forms before entering in the body, but change to gel forms under the physiological conditions.
What kind of polymers can be used in gel forming ophthalmic preparations?
At lower pH (pH 4.4), the formulation exists as a regular solution, however, it undergoes gel formation at pH 7.4, that is the pH of tear fluid. The most commonly used pH-responsive polymers in ophthalmic preparation are Polyacrylic acid (PAA, Carbopol 940), polycarbophil, and cellulose acetate phthalate (CAP) [17].
What is in situ drug?
In situ forming polymeric formulations are drug delivery systems that are in sol form before administration in the body, but once administered, undergo gelation in situ, to form a gel.
How do you make Pharma gel?
Amphiphilic gels can prepared by mixing the solid gelator like sorbitan monostearate or sorbitan monopalmitate and the liquid phase like liquid sorbitan esters or polysorbate and heating them at 60°C to form a clear isotropic sol phase, and cooling the sol phase to form an opaque semisolid at room temperature.
What is gelling capacity?
Gelling capacity is the criterion that is frequently used to evaluate food proteins. The quality characteristics of many foods, especially textural properties and juiciness are determined by the gelling capacity of proteins.
Which polymer is used as viscosity enhancer in topical eye drops?
Cellulose derivatives are used in liquid formulations as viscosity enhancers. They are pH- sensitive polymers and have active surface properties that influence blinking rate [33]. Ahmed et al.
Where is PLGA used?
PLGA, which has FDA approval for drug implants, is widely used for the production of biodegradable and biocompatible micro- and nanoparticles. PLGA has been one of the most commonly used noncondensing polymers in intestinal gene delivery. It has generally been formulated as microparticles to deliver DNA vaccines.
How is PLGA polymer made?
PLGA is synthesized by means of ring-opening co-polymerization of two different monomers, the cyclic dimers (1,4-dioxane-2,5-diones) of glycolic acid and lactic acid. Polymers can be synthesized as either random or block copolymers thereby imparting additional polymer properties.
Which polymers undergo in situ gel formation for drug delivery?
Various natural and synthetic polymers undergo in situ gel forming and potentially can be used for oral, buccal, rectal, vaginal, ocular, intraperitoneal and parenteral drug delivery. Pectin, xyloglucan, gellan gum, chitosan and alginic acid are some of the natural polymers (1). The pectin gelation occurs in the presence of calcium ions.
What are the advantages of in situ gel forming polymeric formulations?
The in situ gel forming polymeric formulations offer several advantages like sustained and prolonged action in comparison to conventional drug delivery systems. The article presents a detailed review of these types of polymeric systems, their evaluation, advancements and their commercial formulations.
What are in situ gels made out of?
Various polymers that are used for the formulation of in situ gels include gellan gum, alginic acid, xyloglucan, pectin, chitosan, poly(DL-lactic acid), poly(DL-lactide-co-glycolide) and poly-caprolactone.
Why in situ gel delivery systems?
The development of in situ gel systems has received considerable attention over the past few years[1]. This interest has been sparked by the advantages shown by in situ forming polymeric delivery systems such as ease of administration and reduced frequency of administration, improved patient compliance and comfort[2].