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Ítem Aggregates of alternate amphiphilc polyanion to carry zwitterionic drug in aquedous media(2015-06-01) Quintero, AndrésThe effect of amphiphilic polyanion Poly(maleic acid-alt-octadecene)sodium salt on solubility of a zwitterionic drug (ampicillin trihydrate) in aqueous media was evaluated. This polymeric salt was obtained by an equimolar reaction of parent copolymer poly Poly(maleic acid-alt-octadecene)with an aqueous solution of NaOH. The obtained amphiphilic polyanion was purified by dialysis and lyophilization and was characterized by FTIR spectroscopy. Secondly, a method for the model drug quantification by UV spectrophotometry at 37°C was standardized. Also the grade of association drug-polymer in aqueous media using ultrafiltration methodology at three levels of temperature (20, 30 and 40°C) and two levels of pH (1.2 and 7.4) was determined. Finally, the variation of aqueous solubility of ampicillin trihydrate in ultra-pure water and two buffer media with pH of 1.2 and 7.4 with an ionic strength of 0.15 M at 37°C in presence and absence of amphiphilic polyanion was evaluated. It was found that maximum solubility is reached at a pH value of 1.2 in absence of polymeric material with a value of 36 mg/mL, which diminishes dramatically to a value of 8.3mg/mL when the polyanion is added. In the other side, when the system has a pH value of 7.4, the drug solubility slightly increases from 13 to 16mg/mL in presence of polymeric material, describing that solubility of this kind of drugs is strongly influenced by aqueous media and this type of polymeric materials.Ítem Relationship between surface properties and in vitro drug release from a compressed matrix containing an amphiphilic polymer materia.(Multidisciplinary Digital Publishing Institute (MDPI), 2016-06-24) Pineda, Diego; Corre, Clara E.; Yarce, Cristhian J.; Salamanca Mejía, Constaín HugoThe performance of compressed tablet drug delivery systems made using polymeric materials depend on multiple factors, such as surface properties like contact angle, surface free energy and water absorption rate, besides the release mechanisms driven by the kind of polymer used. Hence, it should be possible to establish a relationship between the surface properties and the drug release kinetics. Compressed tablets with different proportions of poly(maleic acid-alt-octadecene) potassium salt (0%, 10%, 20%, 30% and 40%) were prepared. Blends of a model drug (ampicillin trihydrate) and the polymer material were analyzed by DSC.