John Garner

PLGA-PEG-PLGA block thermogel investigated for glimepiride delivery system as diabetes treatment

Blog Post created by John Garner on Feb 26, 2016

PolySciTech division of Akina, Inc ( provides a wide array of block copolymers including PLGA-PEG-PLGA thermogels (such as Polyvivo AK097). Recently, these kinds of polymers were used as part of an investigation for novel delivery systems for glimepiride, an anti-diabetic drug. This delivery system involved forming an inclusion complex between glimerpiride and zein (a corn-based protein with many uses) and these nanoparticles were subsequently embedded in thermogelling PLGA-PEG-PLGA for controlled drug delivery application. Read more: Ahmed, Osama Abdelhakim Aly, Ahmed Samir Zidan, and Maan Khayat. "Mechanistic analysis of Zein nanoparticles/PLGA triblock in situ forming implants for glimepiride." International Journal of Nanomedicine 11 (2016): 543.


“Abstract: Objectives: The study aims at applying pharmaceutical nanotechnology and D-optimal fractional factorial design to screen and optimize the high-risk variables affecting the performance of a complex drug delivery system consisting of glimepiride–Zein nanoparticles and inclusion of the optimized formula with thermoresponsive triblock copolymers in in situ gel. Methods: Sixteen nanoparticle formulations were prepared by liquid–liquid phase separation method according to the D-optimal fractional factorial design encompassing five variables at two levels. The responses investigated were glimepiride entrapment capacity (EC), particle size and size distribution, zeta potential, and in vitro drug release from the prepared nanoparticles. Furthermore, the feasibility of embedding the optimized Zein-based glimepiride nanoparticles within thermoresponsive triblock copolymers poly(lactide-co-glycolide)-block-poly(ethylene glycol)-block-poly(lactide-co-glycolide) in in situ gel was evaluated for controlling glimepiride release rate. Results: Through the systematic optimization phase, improvement of glimepiride EC of 33.6%, nanoparticle size of 120.9 nm with a skewness value of 0.2, zeta potential of 11.1 mV, and sustained release features of 3.3% and 17.3% drug released after 2 and 24 hours, respectively, were obtained. These desirability functions were obtained at Zein and glimepiride loadings of 50 and 75 mg, respectively, utilizing didodecyldimethylammonium bromide as a stabilizer at 0.1% and 90% ethanol as a common solvent. Moreover, incorporating this optimized formulation in triblock copolymers-based in situ gel demonstrated pseudoplastic behavior with reduction of drug release rate as the concentration of polymer increased. Conclusion: This approach to control the release of glimepiride using Zein nanoparticles/triblock copolymers-based in situ gel forming intramuscular implants could be useful for improving diabetes treatment effectiveness. Keywords: glimepiride, Zein, nanoparticles, quality by design, in situ implants”