title: Regulation of the tetracycline hydrochloride release from polyacrylate microspheres. Part 1.
abstract: Due to the precipitation of free bases sparingly soluble in water, it is not possible to achieve a uniform release in the gastrointestinal tract of delayed action drugs containing salts of weak bases, e.g. tetracycline hydrochloride, at pH-values surpassing their pKa values. The problem of drug release control can be solved by adding Eudragit L to the polymetacrylate (Eudragit RS) microspheres. It has been established that 30% Eudragit L ensures a gradual uniform release of tetracycline hydrochloride (KOr = 11%/h) irrespective of variations in the pH of the gastrointestinal tract.
authors.affiliation: Research Institute of Pharmacy and Pharmacology, Medical Academy, Sofia, Bulgaria.
authors.forename: S
authors.initials: S
authors.lastname: Tsankov
authors.forename: N
authors.initials: N
authors.lastname: Lambov
authors.forename: E
authors.initials: E
authors.lastname: Minkov
mesh_terms: D000180:Acrylic Resins; D003692:Delayed-Action Preparations; D006863:Hydrogen-Ion Concentration; D008863:Microspheres; D011108:Polymers; D012995:Solubility; D013386:Succinates / Q000737:chemistry; D013752:Tetracycline / Q000008:administration & dosage* / Q000737:chemistry
chemical_list: D000180:Acrylic Resins; D003692:Delayed-Action Preparations; D011108:Polymers; D013386:Succinates; C050528:Eudragit RS; C006903:carbopol 940; C058665:Eudragit RL; D013752:Tetracycline