%0 Journal Article %1 delapaz2017vitro %A de la Paz, Nilia %A Pérez, Dania %A Fernández, Mirna %A García, Caridad M. %A Martínez, Vivian %A Nogueira, Antonio %A García, Oscar %D 2017 %E JPPRes, %J Journal of Pharmacy & Pharmacognosy Research %K chitosan chitosan-acetate dibucaine-hydrochloride release semisolid-vehicles %N 2 %P 96-105 %T In vitro release of dibucaine hydrochloride from chitosan semisolid vehicles: emulsion and hydrophilic gels %U http://jppres.com/jppres/pdf/vol5/jppres16.164_5.2.96.pdf %V 5 %X Context: Chitosan has received attention as a functional, sustainably renewable, nontoxic and biodegradable biopolymer for pharmaceutical applications. Aims: To evaluate the release of dibucaine hydrochloride from semisolid vehicles of oil/aqueous type emulsion and aqueous gels, stabilized by using chitosan (CH) or chitosan acetate (CHAc). Methods: Emulsions were developed by varying the emulsifying agent: polysorbate 80, CH or CHAc and by combining CH with polysorbate 80 or CHAc with polysorbate 80. The hydroxypropylmethyl cellulose F4M was added as a stabilizing agent in gel formulations. The release rates of model drug from semisolid vehicles were measured by using a dialysis sac. Drug release was also quantified by using a validated UV-VIS spectrophotometric method. Results: The pH values showed minimal changes for emulsion and gel formulations. The drug is a cationic salt, and it is not able to bind polymer cations by electrostatic repulsion. The rheological property of the vehicle type emulsion was adjusted to plastic and pseudo-plastic fluid to the gels. The drug release was independent of the viscosity of vehicles. Dibucaine release from both types of formulation was found to follow a square-root-of-time kinetic model, but a higher rate of release was obtained from gel formulations. Conclusions: It was shown that chitosan was adsorbed to the surface of polysorbate 80-coated droplets, and that the electrostatic attraction between the non-ionic surfactant and the drug retarded its release from a semisolid system. The multilayer emulsions showed more influence of the release of drug than CH or CHAc single layer emulsion.

@article{delapaz2017vitro, abstract = {Context: Chitosan has received attention as a functional, sustainably renewable, nontoxic and biodegradable biopolymer for pharmaceutical applications. Aims: To evaluate the release of dibucaine hydrochloride from semisolid vehicles of oil/aqueous type emulsion and aqueous gels, stabilized by using chitosan (CH) or chitosan acetate (CHAc). Methods: Emulsions were developed by varying the emulsifying agent: polysorbate 80, CH or CHAc and by combining CH with polysorbate 80 or CHAc with polysorbate 80. The hydroxypropylmethyl cellulose F4M was added as a stabilizing agent in gel formulations. The release rates of model drug from semisolid vehicles were measured by using a dialysis sac. Drug release was also quantified by using a validated UV-VIS spectrophotometric method. Results: The pH values showed minimal changes for emulsion and gel formulations. The drug is a cationic salt, and it is not able to bind polymer cations by electrostatic repulsion. The rheological property of the vehicle type emulsion was adjusted to plastic and pseudo-plastic fluid to the gels. The drug release was independent of the viscosity of vehicles. Dibucaine release from both types of formulation was found to follow a square-root-of-time kinetic model, but a higher rate of release was obtained from gel formulations. Conclusions: It was shown that chitosan was adsorbed to the surface of polysorbate 80-coated droplets, and that the electrostatic attraction between the non-ionic surfactant and the drug retarded its release from a semisolid system. The multilayer emulsions showed more influence of the release of drug than CH or CHAc single layer emulsion.}, added-at = {2017-01-04T05:50:09.000+0100}, author = {de la Paz, Nilia and Pérez, Dania and Fernández, Mirna and García, Caridad M. and Martínez, Vivian and Nogueira, Antonio and García, Oscar}, biburl = {https://www.bibsonomy.org/bibtex/28dcacdbb1af4db85a8caa6d3237bdb2e/jppres}, editor = {JPPRes}, interhash = {ae9d57eecdcf60ef04f3b4c78ffbe651}, intrahash = {8dcacdbb1af4db85a8caa6d3237bdb2e}, journal = {Journal of Pharmacy & Pharmacognosy Research}, keywords = {chitosan chitosan-acetate dibucaine-hydrochloride release semisolid-vehicles}, month = {mar-apr}, number = 2, pages = {96-105}, timestamp = {2017-01-04T05:50:09.000+0100}, title = {In vitro release of dibucaine hydrochloride from chitosan semisolid vehicles: emulsion and hydrophilic gels}, url = {http://jppres.com/jppres/pdf/vol5/jppres16.164_5.2.96.pdf}, volume = 5, year = 2017 }