Development of a poly(ortho ester) prototype with a latent acid in the polymer backbone for 5-fluorouracil delivery

Ng, Siu‐Choon; Shen, H.-R.; López, E.; Zherebin, Yu. L.; Barr, John T.; Schacht, Etienne; Heller, Jorge

doi:10.1016/s0168-3659(99)00218-7

Cited by 45 publications

(15 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, the degradation of POEs is generally confined to the surface layer, essentially resulting in an erosion‐controlled release of encapsulated compounds. In accordance, long‐term zero‐order release has been shown in several studies on low molecular weight drugs encapsulated in (semisolid) POE 2–7. The biocompatibility of these POEs is good, and the degradation products consist of relatively harmless compounds like pentaerythritol and propionic acid 8.…”

Section: Introductionmentioning

confidence: 66%

“…The biocompatibility of these POEs is good, and the degradation products consist of relatively harmless compounds like pentaerythritol and propionic acid 8. Whereas earlier types of POE required the admixing of an acidic compound to result in POE degradation,2,4,9 the newer types contain a latent acid in the backbone 6. Indiffusion of water and subsequent ester degradation result in a local drop of pH, which in turn catalyzes the ortho ester degradation.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Semisolid, Self-Catalyzed Poly(Ortho Ester)s As Controlled-Release Systems: Protein Release and Protein Stability Issues

Weert

Steenbergen

Cleland³

et al. 2002

Journal of Pharmaceutical Sciences

View full text Add to dashboard Cite

Section: Introductionmentioning

confidence: 66%

Section: Introductionmentioning

confidence: 99%

Semisolid, Self-Catalyzed Poly(Ortho Ester)s As Controlled-Release Systems: Protein Release and Protein Stability Issues

Weert

Steenbergen

Cleland³

et al. 2002

Journal of Pharmaceutical Sciences

View full text Add to dashboard Cite

“…Surface-erosion (as opposed to bulk erosion) might have an advantage in that water would theoretically be excluded from the encapsulated protein until the moment of release. Poly(ortho esters) are a potential biodegradable matrix in this regard (Heller 1985;Heller & Gurny 1999;Ng et al 2000).…”

Section: Moisture-induced Protein Aggregation In Microspheresmentioning

confidence: 99%

Recent trends in stabilizing protein structure upon encapsulation and release from bioerodible polymers

Pérez

Castellanos

Costantino

et al. 2002

Journal of Pharmacy and Pharmacology

161

113

View full text Add to dashboard Cite

Sustained release of pharmaceutical proteins from biocompatible polymers offers new opportunities in the treatment and prevention of disease. The manufacturing of such sustained-release dosage forms, and also the release from them, can impose substantial stresses on the chemical integrity and native, three-dimensional structure of proteins. Recently, novel strategies have been developed towards elucidation and amelioration of these stresses. Non-invasive technologies have been implemented to investigate the complex destabilization pathways that can occur. Such insights allow for rational approaches to protect proteins upon encapsulation and release from bioerodible systems. Stabilization of proteins when utilizing the most commonly employed procedure, the water-in-oil-in-water (w/o/w) double emulsion technique, requires approaches that are based mainly on either increasing the thermodynamic stability of the protein or preventing contact of the protein with the destabilizing agent (e.g. the water/oil interface) by use of various additives. However, protein stability is still often problematic when using the w/o/w technique, and thus alternative methods have become increasingly popular. These methods, such as the solid-in-oil-in-oil (s/o/o) and solid-in-oil-in-water (s/o/w) techniques, are based on the suspension of dry protein powders in an anhydrous organic solvent. It has become apparent that protein structure in the organic phase is stabilized because the protein is "rigidified" and therefore unfolding and large protein structural perturbations are kinetically prohibited. This review focuses on strategies leading to the stabilization of protein structure when employing these different encapsulation procedures.

show abstract

“…Several approaches were proposed to overcome this problem, including the use of block copolymers of PLGA and poly(ethylene glycol) (PEG) [12], and addition of zinc carbonate [13]. Poly(ortho esters) (POEs), a versatile family of biodegradable and biocompatible polymers, are receiving significant attention because they can be designed to possess a surface-dominant erosion mechanism, and thus provide a zero-order release profile for various therapeutic agents [14][15][16][17][18][19][20][21]. Recently, Chia et al [22] reported bovine serum albumin (BSA)-loaded POE microspheres fabricated by a water-in-oil-in-water double emulsion solvent extraction process.…”

Section: Introductionmentioning

confidence: 99%

Preparation, characterization, and in vitro evaluation of physostigmine-loaded poly(ortho ester) and poly(ortho ester)/poly(d,l-lactide-co-glycolide) blend microspheres fabricated by spray drying

et al. 2004

View full text Add to dashboard Cite

Development of a poly(ortho ester) prototype with a latent acid in the polymer backbone for 5-fluorouracil delivery

Cited by 45 publications

References 6 publications

Semisolid, Self-Catalyzed Poly(Ortho Ester)s As Controlled-Release Systems: Protein Release and Protein Stability Issues

Semisolid, Self-Catalyzed Poly(Ortho Ester)s As Controlled-Release Systems: Protein Release and Protein Stability Issues

Recent trends in stabilizing protein structure upon encapsulation and release from bioerodible polymers

Preparation, characterization, and in vitro evaluation of physostigmine-loaded poly(ortho ester) and poly(ortho ester)/poly(d,l-lactide-co-glycolide) blend microspheres fabricated by spray drying

Contact Info

Product

Resources

About