Preparation and drug-release behavior of 5-fluorouracil-loaded poly(lactic acid–4-hydroxyproline–polyethylene glycol) amphipathic copolymer nanoparticles

2006 ◽  
Vol 103 (4) ◽  
pp. 2654-2659 ◽  
Author(s):  
Jiufang Duan ◽  
Jie Du ◽  
Yu Bin Zheng
Keyword(s):  
Lactic Acid ◽  
Polyethylene Glycol ◽  
Drug Release ◽  
Poly Lactic Acid ◽  
Release Behavior ◽  
Drug Release Behavior

Preparation and Drug Release Behavior of Nifedipine-Loaded Poly(lactic acid)/Polyethylene Glycol Microcapsules

2021 ◽  
Vol 21 (7) ◽  
pp. 3735-3741
Author(s):  
Heeseok Jeong ◽  
Hyunju Lim ◽  
Deuk Yong Lee ◽  
Yo-Seung Song ◽  
Bae-Yeon Kim
Keyword(s):  
Lactic Acid ◽  
Polyethylene Glycol ◽  
Drug Release ◽  
Release Rate ◽  
Drug Carriers ◽  
Poly Lactic Acid ◽  
Release Behavior ◽  
Drug Release Rate ◽  
Water Emulsion ◽  
Drug Release Behavior

Nifedipine (NF)-loaded poly(lactic acid) (PLA) and PLA/polyethylene glycol (PLA/PEG) microcapsules are synthesized using a high-speed agitator and a syringe pump with an oil-in-water emulsion-solvent evaporation technique to evaluate the effect of PLA/PEG ratio on morphology and drug release behavior of the capsules. Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimeter (DSC), and X-ray diffraction (XRD) results indicate that PEG reacts successfully with PLA due to the ether bond between PEG and PLA. The drug release rate of PLA and PLA/PEG capsules increases dramatically from 0 to 5 min and then reaches a plateau within 15 to 20 min. Due to the high specific surface area, the amount of NF released is raised by reducing the PLA concentration from 5 wt% to 2 wt%. Unlike PLA capsules, the drug release rate of PLA/PEG capsules increases due to the size effect by varying the PLA/PEG ratio from 10/0 to 6/4. Larger PLA/PEG capsules are attributed to higher amounts of encapsulated NF. The capsules show no evidence of cytotoxicity, suggesting that the PLA and PLA/PEG drug carriers are clinically safe.

Synthesis and Kinetic Studies on Controlled Release of 6-Thioguanine Entrapped Polyethylene Glycol-Co-Polylactic Acid Polymer Nanoparticles

2011 ◽  
Vol 9 (1) ◽  
Author(s):  
Sathishkumar Kannaiyan ◽  
T.G.Ashwin Narayanan ◽  
P.Karthick Sarathy ◽  
Nagarjun Sudhakar ◽  
Rama Krishnan
Keyword(s):  
Gold Nanoparticles ◽  
Lactic Acid ◽  
Polyethylene Glycol ◽  
Controlled Release ◽  
Drug Release ◽  
Kinetic Equations ◽  
Kinetic Studies ◽  
Poly Lactic Acid ◽  
Average Size

Poly lactic acid-polyethylene glycol (PLA-co-PEG) copolyester was synthesized from oligomer of L-lactic acid and poly ethylene glycol (PEG) using stannous octoate as catalyst. 6-Thioguanine containing Poly lactic acid-polyethylene glycol (PLA-co-PEG) nanocapsules were prepared in the presence and absence of gold nanoparticles via the W/O/W emulsification solvent-evaporation method. The morphologies of prepared nanocapsules changed substantially because of the presence of gold nanoparticles. From SEM and TEM measurements, the average size of the polymer nanocapsules and gold nanoparticles were found to be in range of 230-260 nm and 18-20 nm, respectively. In general the drug release was quicker in Phosphate buffer saline (pH 7.4) compared to 0.1M hydrochloric acid and this may be due to higher solubility, higher swelling and penetration properties of PLA-co-PEG in PBS compared to HCl. Polymer nanocapsules with gold show a prolonged controlled release with higher encapsulation efficiency (75%) compared to that of polymer nanocapsules (45%) in the absence of gold nanoparticles. It may be due to the more entrapping efficiency of gold and less diffusivity of drugs from the nanocapsules. Application of in vitro drug release data to various kinetic equations indicated Higuchi model, indicating a uniform distribution of thioguanine in the nanocapsules.

A New Approach for Polymer-Free Coating with Paclitaxel Microparticles on Fully-Bioabsorbable Poly(l-Lactic Acid) Stent and Studies of Drug Release Behavior

2015 ◽  
Vol 5 (2) ◽  
Author(s):  
Hirokazu Yamada ◽  
Mitsuhiko Kinoshita ◽  
Shinichi Yagi ◽  
Chisa Matsubara ◽  
Keiji Igaki ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Crystal Growth ◽  
Drug Release ◽  
Aqueous Solubility ◽  
Release Behavior ◽  
Drug Release Behavior ◽  
Initial Release ◽  
Antiproliferative Agent ◽  
Plla Stent ◽  
Growth Formation

A first clinically-used, fully-bioabsorbable poly(L-lactic acid) (PLLA) stent was coated with microcrystals of paclitaxel (PTX), antiproliferative agent through seeding and/or crystal growing technique to investigate the drug properties on the stent surface and drug release behavior from the stent. PTX particles subject to only seeding process was peeled off after stent compression, while less PTX was coated on the stent subject to only crystal growth without seeding. PLLA stent with both processes could stably maintain an increased amount of PTX on its surface. The maximum amount of initial release (10 μg/cm2) was found in the sample only with seeding, which decreased to 3 μg/cm2 or below after one week. Also in the PLLA stent only with crystal growth, release amount decreased after one week. In the PLLA stent with seeding and crystal growth, formation of needle-like PTX crystals on the surface resulted in decreased initial release and lower solubility after hydration in phosphate buffered solution compared to other types of stent with different procedures. It is suggested that both seeding and crystal growth are required for stable application of PTX on fully-bioabsorbable PLLA stent and needle-like crystals containing water have lower aqueous solubility resulting in decreased PTX release.

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