Kinetics of drug release from drug carrier of polymer/TiO₂ nanotubes composite—pH dependent study

Abstract

This study was to investigate the kinetics of drug release from polymer/TiO2 nanotubes composite. Lidocaine and carprofen were selected as model drugs to represent weak base and weak acid drugs, respectively. Mathematical models used to fit the in vitro drug release experimental data indicate that at higher pH, the drug release was first order diffusion controlled. At lower pH, the release of the two drugs exhibits two staged controlled release mechanism. The first phase is due to drug diffusion and the second stage is a result of poly(lactic‐co‐glycolic acid) (PLGA) polymer degradation. The rate of drug release from polymer/TiO2 nanotubes drug carrier was mainly controlled by three pH dependent factors: the solubility of the drug, the degree of polymer swelling/degradation, and the electrostatic force between polymer and drug. This study suggests that controlled release could be achieved for polymer/TiO2 nanotubes drug carrier via the modulation of pKa values of polymers and drug solubility. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41570.

Construction of pH-responsive and up-conversion luminescent NaYF4:Yb3+/Er3+@SiO2@PMAA nanocomposite for colon targeted drug delivery

“…7 ). Actually, the degree of ionized of 5-ASA in different pH solutions can be calculated by Henderson-Hasselbalch formula 58 59 .…”

Recent advances on smart TiO₂ nanotube platforms for sustainable drug delivery applications

“…[19][20][21][22][23][24][25][26][27][28][29][30][31] In order to improve the technology of TNT fabrication, various electrochemical protocols were addressed to support it, which involve aqueous and organic electrolytes with different chemical compositions and electrochemical conditions. The electrochemical anodization process is carried out usually in electrolytes containing some fluoride ions to fabricate TNT layers.…”

TiO₂ nanotube platforms for smart drug delivery: a review

“…Jia et al reported that poly(lactic-coglycolic acid) (PLGA) added into TNTs could improve the drug release profile. 77 In their study, carprofen and lidocaine were used as the model drugs to investigate the drug release profile using PLGA/TNTs with different types of drugs. To investigate drug release from PLGA/TNTs under different pH conditions, lidocaine and carprofen releases were studied in sodium acetate buffer with pH 3.5, phosphate-buffered saline with pH 7.4, and phosphate buffer with pH 10.5, respectively, under the constant temperature of 37°C.…”

“…The drug can easily diffuse into the medium through the swelling polymer during the critical time t 1 as shown in Figure 4, followed the t 2 time region, where the remaining drug completely releases as a result of polymer degradation. 77 Furthermore, in order to reveal the mechanism and potential of lidocaine and carprofen release from TNTs, the drug release profiles were investigated on the basis of drug-loaded pure TNTs and drug-loaded PLGA/TNTs; the former was used as the control sample. 77 For temperature-sensitive drug delivery based on TNTs, temperature-responsive polymers were explored to decorate TNT implants.…”

“…77 Furthermore, in order to reveal the mechanism and potential of lidocaine and carprofen release from TNTs, the drug release profiles were investigated on the basis of drug-loaded pure TNTs and drug-loaded PLGA/TNTs; the former was used as the control sample. 77 For temperature-sensitive drug delivery based on TNTs, temperature-responsive polymers were explored to decorate TNT implants. Cai et al fabricated a temperature-sensitive drug delivery system based on TNTs by using vitamin B 2 as a model drug and explored kinetics of controlled drug release from TNTs with temperature-responsive trigger.…”