Oros Colon Targeting: Components 1. Semipermeable membrane 2. Hard gelatin capsule Working This has one osmoticagent or it comprises ofas many as 5 tosi6 push pull osmotic unit occupied in a hardgelatin capsule. After next inassociation with the aqueous surroundings, gelatin capsule dissolved (liquefy) and the enteric coatingavoids entry of extracts from stomach to thesystem, when system permit into the small intestine the enteric coating dissolves and water is absorbed into the core thus affecting the push compartment to swell. At the same time flow-able gel is formed in thedrug compartment, which is pushed out of the orifice at a rate, which is precisely controlled, by the rate of water transport crossways the semi permeable membrane Advantage It is used as a one or twotimes a day formulation for site exact delivery of drugs to the colon. Monolithicosmotic system: Components 1.
Polymer matrix capsule 2. Semi permeable membrane Functioning It consists of a simple dispersion of water-soluble species in a polymer matrix .When thesystem approaches acrosswith the aqueous environment water imbibition by the active agent’sresults in distortion of the polymer matrix capsule encapsulating thedrug this supplying it tothe outside environment. Mostly this method proceeds atthe external environment of the polymeric matrix, butslowly leads towards the inside of the matrix in asequential manner, but this system is not succeeded if more than 20 –30 volumes per liter of the active agents are joint in to the device cross this level, significant contribution from the simple discharge of thesubstance take place Osmotic Matrix Tablet (OSMAT): Components1. Hydrophilic polymer 2. Gelin aqueous media creating semi permeableWorking This type ofsystem employs the swellings property of hydrophilic polymer, which swells and gels in aqueous medium making a semipermeable membrane in situ. The speed of drug delivery from this system is affected by the insertion of osmogent witha matrix delivery of drug from OSMAT don’t rely on agitation & is lowcost method.
Evaluation aspects of osmoticDDS Ø Powder evaluation WeightBulk density Tapped density Carr’s index Angle of repose Ø Tablet evaluationContent uniformity Hardness Thickness Friability Effect of Ph. Stabilitystudies Dissolution Disintegration