Effects of the type of release medium on drug release from PLGA-based microparticles: Experiment and theory

Faisant, N.; Akiki, J; Siepmann, Florence; Benoit, Jean‐Pierre; Siepmann, J.

doi:10.1016/j.ijpharm.2005.07.030

Cited by 143 publications

(107 citation statements)

References 25 publications

Supporting

Mentioning

102

Contrasting

Unclassified

Order By: Relevance

“…The rest release superimposed the polymer erosion and often became extremely slow. 25,26 The in vitro release of BSA showed that the polymer concentration played an important role in controlling the release from the microspheres. A higher polymer concentration resulted in a microsphere layer with higher density and thickness.…”

Section: Bsa Release From Microspheres and Microsphere Degradationmentioning

confidence: 99%

Preparation and properties of BSA-loaded microspheres based on multi-(amino acid) copolymer for protein delivery

Chen

Zhang

et al. 2014

IJN

View full text Add to dashboard Cite

A multi-(amino acid) copolymer (MAC) based on ω-aminocaproic acid, γ-aminobutyric acid, L-alanine, L-lysine, L-glutamate, and hydroxyproline was synthetized, and MAC microspheres encapsulating bovine serum albumin (BSA) were prepared by a double-emulsion solvent extraction method. The experimental results show that various preparation parameters including surfactant ratio of Tween 80 to Span 80, surfactant concentration, benzyl alcohol in the external water phase, and polymer concentration had obvious effects on the particle size, morphology, and encapsulation efficiency of the BSA-loaded microspheres. The sizes of BSA-loaded microspheres ranged from 60.2 μm to 79.7 μm, showing different degrees of porous structure. The encapsulation efficiency of BSA-loaded microspheres also ranged from 38.8% to 50.8%. BSA release from microspheres showed the classic biphasic profile, which was governed by diffusion and polymer erosion. The initial burst release of BSA from microspheres at the first week followed by constant slow release for the next 7 weeks were observed. BSA-loaded microspheres could degrade gradually in phosphate buffered saline buffer with pH value maintained at around 7.1 during 8 weeks incubation, suggesting that microsphere degradation did not cause a dramatic pH drop in phosphate buffered saline buffer because no acidic degradation products were released from the microspheres. Therefore, the MAC microspheres might have great potential as carriers for protein delivery.

show abstract

Section: Bsa Release From Microspheres and Microsphere Degradationmentioning

confidence: 99%

Preparation and properties of BSA-loaded microspheres based on multi-(amino acid) copolymer for protein delivery

Chen

Zhang

et al. 2014

IJN

View full text Add to dashboard Cite

show abstract

“…The PLGA particles may protect the drug, gene and vaccine against degradation and ensure their transport and delivery [13,14], and also can control the release rate and achieve targeting [15][16][17][18]. Among the method for preparation of PLGA particles, the emulsification-solvent evaporation is the most frequently employed one [19].…”

mentioning

confidence: 99%

Preparation and cellular uptake of PLGA particles loaded with lamivudine

et al. 2012

View full text Add to dashboard Cite

Poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles loaded with lamivudine and coated with bovine serum albumin (BSA) were prepared via a double emulsion method. The influences of experiments parameters such as volume of inner aqueous phase, concentration of organic phase and ultrasonication time on the particle size and drug entrapment efficiency were investigated, obtaining PLGA particles with a diameter of ~260 nm and drug entrapment efficiency of ~35%. The particles were observed by scanning electron microscopy and transmittance electron microscopy, showing a core-shell structure. BCA assay found that 58 mg BSA was present on/in 1 g LPB particles. The loaded lamivudine showed a burst release at beginning and sustained release until 24 h in physiological conditions. Low pH could accelerate the release of lamivudine from PLGA particles, making the PLGA particles potential intelligent intracellular drug carriers. The PLGA particles were readily internalized into the human liver cells within a short time and increased gradually with the prolongation of incubation time regardless of the loading of lamivudine. The particles either resided within lysosomes or transferred to cytoplasm, but could not enter into the cell nucleus. The cell viability was not significantly influenced in the presence of the particles regardless of lamivudine encapsulation, suggesting that this kind of particles may be a good candidate for the intracellular anti-hepatitis B drug delivery.PLGA, lamivudine, cell uptake, intracellular distribution, drug delivery Citation:Wang B, Chen G Q, Mao Z W, et al. Preparation and cellular uptake of PLGA particles loaded with lamivudine.

show abstract

“…42 The initial stage is attributed to burst release, which is mainly diffusion mediated. The secondary phase is characterized by a steady release rate and is attributed to a balance between increased drug mobility due to hydrolysis of PLGA chains, and the increasing distance that drugs farther from the surface must diffuse.…”

Section: Resultsmentioning

confidence: 99%

“…The secondary phase is characterized by a steady release rate and is attributed to a balance between increased drug mobility due to hydrolysis of PLGA chains, and the increasing distance that drugs farther from the surface must diffuse. 42 The final accelerated release phase is explained by the local build-up of lactic and glycolic acid, the PLGA degradation byproducts, which have an auto-catalytic effect on polyester degradation. 43 Eventually the PLGA chains breakdown to a critical state such that the microparticle structure starts to disintegrate.…”

Section: Resultsmentioning

confidence: 99%

Design of Protein‐Releasing Chitosan Channels

Kim¹,

Tator²,

Shoichet³

2008

Biotechnology Progress

View full text Add to dashboard Cite

After traumatic injury to the spinal cord, the neural tissue degenerates, resulting in lost function below the site of injury. Promoting axonal regeneration after injury remains a challenge; however, guidance channels have demonstrated some success when combined with cellular and protein therapies. One of the limitations of current guidance channels is the inability to deliver therapeutically relevant molecules in situ, within the guidance channel, to enhance regeneration. In an effort to provide a system for local and sustained drug release, poly(lactide-co-glycolide) (PLGA) microspheres were embedded into chitosan guidance channels by a novel spin-coating technique. The method was designed to create guidance channels with the appropriate dimensions for implantation into the spinal cord, with special attention paid to the wall thickness. The release and bioactivity of a model protein, alkaline phosphatase, was followed from the channels and compared to those from free-floating microspheres over a 90-day period. Since chitosan formulations often require the use of acidic solutions, careful attention was paid to redesign the process to minimize exposure of PLGA microspheres to acid. This was achieved as demonstrated by release and bioactivity data where alkaline phosphatase released from chitosan/microsphere channels followed a profile and bioactivity similar to those of free floating microspheres.

show abstract

Effects of the type of release medium on drug release from PLGA-based microparticles: Experiment and theory

Cited by 143 publications

References 25 publications

Preparation and properties of BSA-loaded microspheres based on multi-(amino acid) copolymer for protein delivery

Preparation and properties of BSA-loaded microspheres based on multi-(amino acid) copolymer for protein delivery

Preparation and cellular uptake of PLGA particles loaded with lamivudine

Design of Protein‐Releasing Chitosan Channels

Contact Info

Product

Resources

About