title: In vitro release behaviour of theophylline from PIB-induced ethylcellulose microcapsules interpreted by simple mathematical functions.
abstract: Theophylline microcapsules were prepared by phase separation using polyisobutylene as a coacervation-inducing agent. The release rate was dependent on the molecular weight of the polyisobutylene used. A simple mathematical function has been used for the quantitative description of the release process of the drug from PIB-induced microcapsules. It was found that 1/y = A(1/x) + B is the best for interpreting the release process of microcapsules, since the values of the constants A and B are proportional to the amount of the drug released.
mesh_terms: D002214:Capsules; D002482:Cellulose / Q000031:analogs & derivatives; D008433:Mathematics; D008956:Models, Chemical; D008970:Molecular Weight; D011090:Polyenes / Q000494:pharmacology*; D011108:Polymers / Q000494:pharmacology*; D013806:Theophylline / Q000008:administration & dosage*
chemical_list: D002214:Capsules; D011090:Polyenes; D011108:Polymers; C013517:ethyl cellulose; C008967:polyisobutylene; D002482:Cellulose; D013806:Theophylline