controlled release

Ion exchange resins are cross-linked water insoluble polymer-carrying, ionisable functional groups. IER have received considerable attention from pharmaceutical scientists because of their versatile properties as drug delivery vehicles. Research over the last few years has revealed that IER are equally suitable for drug delivery technologies, including controlled release, transdermal, nasal, topical and taste masking. The major drawback of sustained release of extended release or extended release is dose dumping, resulting in increased risk of toxicity. The use of IER has occupied an important place in the development of controlled- or sustained-release systems because of their better drug-retaining properties and prevention of dose dumping. Synthetic ion exchange resins have been used in pharmacy and medicine for taste masking or controlled release of drug. Drug resin complexation converts drug to amorphous form leading to improved drug dissolution. Several studies have reported the use of IER for drug delivery at the desired site of action. Keywords: Ion exchange resins, taste masking, resin drug complex, controlled release

Over the past decade, numerous limitations of conventional dosage forms had attracted researchers to find a rational and appropriate drug delivery system. Microsponges were developed and studied as a novel programmable delivery system which is intended to deliver drug in controlled release pattern. It also aims epidermal localization of topical drug therapy to reduce their side effects by limiting systemic absorption through skin. Drug loaded microsponges are microporous beads, typically 10-25 µm in diameter which can entrap a wide variety of actives and can be formulated as creams, lotions, gels, ointments, powders, soaps. Microsponge formulations can increase product stability, enhance aesthetic qualities, and provide formulation flexibility and stability. Moreover, their non-antigenicity, non-toxicity, non-mutagenicity and non-biodegradability make them favourable candidates. Microsponge approach has also been applied in oral therapy, bone, tissue & cartilage engineering and showed remarkable results. This article provides description about the nature of microsponges, their characteristics, preparation, applications and commercial market status globally.

Nanosponges are the advancement in nano technology, which are the conspicuous answers for the various formulation challenges like low aqueous solubility, controlled release and targeted release. Nanosponges do not show the bursting release which is the main obstacle in the most of the nano particles formulations. Nanosponges are a novel class of nanoparticles with nanostructured hyper branched polymers and few nanometres wide cavities, in which a large variety of substances can be encapsulated. Nanosponges also have colloidal sizes with a mean diameter of less than 1 μm and narrow size distribution and form opalescent suspensions on dispersion in water. The formulation of nanosponges involves simple chemistry. Nanosponges could be a perfect solution for resolving the scalability issues of various nano approaches in the pharmaceutical industry, paving the way for a nano-revolution.