02013nas a2200241   4500008004100000022001400041245008600055210006900141260009000210300001000300490000700310520116100317653001401478653001201492653002001504653001901524653001901543653001701562653002201579100002201601700003201623856011601655       2012                        eng d  a0363-904500apH Sensitive graft copolymers for zero order drug release: a mechanistic analysis0 apH Sensitive graft copolymers for zero order drug release a mech  aTELEPHONE HOUSE, 69-77 PAUL STREET, LONDON EC2A 4LQ, ENGLANDbINFORMA HEALTHCAREcJAN  a73-830 v383 a<p>Aliphatic polyesters containing pendent unsaturation were synthesized by the polycondensation of a diol, dicarboxylic acid and glycidyl methacrylate. Grafting methacrylic acid (MAA) resulted in graft copolymers containing polyester backbone and MAA grafts. Depending on composition, the polymers swelled extensively and eroded or dissolved at near neutral pH but remained in collapsed state at acidic pH. Three representative drugs differing in solubility, viz., Diltiazem hydrochloride (DH), Indomethacin (IM) and Verapamil hydrochloride (VH) were released at constant rate from tablets made by compressing spray-dried microparticles. The release of DH at constant rate has been attributed to increase in diffusion coefficient of the drug from the swollen layer of matrix. The release of IM and VH at constant rate was governed by erosion and was enhanced in matrices which undergo dissolution. The release rate was enhanced with increasing MAA content and the frequency of grafts along the polyester backbone. Once a day dosage forms for drugs differing in solubility have been developed using a single polymer matrix which is easy to manufacture.</p>10aDiffusion10aerosion10aGraft copolymer10amatrix tablets10amicroparticles10aspray drying10asustained release1 aMuthusamy, Ramesh1 aKulkarni, Mohan, Gopalkrish  uhttps://library.ncl.res.in/content/ph-sensitive-graft-copolymers-zero-order-drug-release-mechanistic-analysis-002214nas a2200229   4500008004100000022001400041245010200055210006900157260000800226300001100234490000800245520141200253653003101665653002301696653001701719653002201736100002001758700002501778700002201803700003101825856012801856       2025                        eng d  a1381-514800aSustained release polyurethane microcapsules by interfacial polycondensation using aromatic diols0 aSustained release polyurethane microcapsules by interfacial poly  cNOV  a1064600 v2163 a<p>
	Polyurea-urethane (PUU) microcapsules prepared via interfacial polymerization have gained significant interest due to their tunable size and membrane thickness, high loading efficiency, and scalability. Although several aromatic and aliphatic diols and polyols have been used to produce PU foams and films, the use of aromatic diols to synthesize PUU MICs via interfacial polymerization is an unexplored domain due to the restricted solubility of aromatic diols in water. This report highlights the successful preparation of PUU microcapsules using an aromatic diol (benzene-1,4-dimethanol, BDM) to encapsulate dimethyl phthalate (DMP), a model insect repellent. The developed PUU microcapsules exhibited a high % encapsulation efficiency of 92 % and a size range of 1-20 mu m. Differential scanning calorimetry (DSC) thermograms revealed a significantly high glass transition temperature (Tg) of 143 degrees C as compared to 108 degrees C in the case of PUU MICs with aliphatic diols. Release studies confirm enhanced barrier properties for aromatic diol-based MICs as compared to aliphatic ethylene glycol-based PUU MICs, and interpretation of the release profile using the Weibull Model reveals that Fickian diffusion is the dominant mechanism in the release of DMP. These microcapsules can be used in high-performance applications such as composites, coatings, electronics, and construction.</p>
10ainterfacial polymerization10aMicroencapsulation10apolyurethane10asustained release1 aYadav, Prashant1 aRavikumar, Aniruddha1 aAmbade, Ashootosh1 aShanmuganathan, Kadhiravan  uhttps://library.ncl.res.in/content/sustained-release-polyurethane-microcapsules-interfacial-polycondensation-using-aromatic