Premium
The kinetics of isothermal nicotinamide release from poly(acrylic‐ co ‐methacrylic acid) loaded xerogel
Author(s) -
Djajic Tatjana,
Jovanovic Jelena,
Potkonjak Biljana,
Adnadjevic Borivoj
Publication year - 2015
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.23870
Subject(s) - nicotinamide , methacrylic acid , acrylic acid , activation energy , kinetics , poly(methacrylic acid) , materials science , polymer chemistry , isothermal process , reaction rate constant , polymerization , chemistry , organic chemistry , polymer , copolymer , thermodynamics , physics , quantum mechanics , composite material , enzyme
The isothermal kinetics of in vitro nicotinamide release from poly(acrylic‐ co ‐methacrylic acid) loaded xerogel into water was evaluated. The isothermal kinetics curves of nicotinamide release from poly(acrylic‐ co ‐methacrylic acid) xerogel were measured at different temperatures ranging from 296 K to 315 K. It was proven that the kinetics of nicotinamide release from poly(acrylic‐ co ‐methacrylic acid) xerogel was a kinetically complex process which was neither controlled by the processes of drug diffusion nor with the relaxation of the xerogel. The kinetic of nicotinamide release from poly(acrylic‐ co ‐methacrylic acid) may be described by the kinetics model of reversible first order chemical reaction and the apparent activation energy have value of E a,M = 14.1 kJ mol −1 and preexponential factor ln( A M min −1 ) = 2.3. The rate constants of nicotinamide release ( k R ) and the rate constants of its reversible absorption reaction ( k A ) were calculated and found to fall within the range 0.019 min −1 −0.033 min −1 fork Rand 0.014 min −1 −0.016 min −1 fork A . The value of activation energy for the nicotinamide releas, E a.R =21.25 kJ mol −1 , is significantly higher than the value for the process of nicotinamide absorption ( E a,A = 2.6 kJ mol −1 ). The rate of nicotinamide release was predetermined with the rate of nicotinamide molecules distribution between the hydrogel and surrounding solution. POLYM. ENG. SCI., 55:60–69, 2015. © 2014 Society of Plastics Engineers