Controlled release of 5-fluorouracil from linear poly(ortho esters)

Maa, Y. F.; Heller, Jorge

doi:10.1016/0168-3659(90)90070-a

Cited by 24 publications

(3 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The most promising family of liner or cross‐linked POEs was prepared by the addition of polyols to diketene acetal 3,9‐diethylidene‐2,4,8,10‐tetraoxaspiro[5,5]undercane 5. POEs have been studied for the delivery of various active compounds, such as pyrimethamin,6 5‐fluorouracil,7–9 naltrexone,10 contraceptive steroids,11, 12 prostaglandin,13 and insulin 14. Since the POE molecule contains pH‐sensitive linkages, its hydrolysis rate can be increased by acidic excipients such as suberic acid or retarded by basic excipients such as magnesium hydroxide.…”

Section: Introductionmentioning

confidence: 99%

Effect of polymer compositions on the fabrication of poly(ortho‐ester) microspheres for controlled release of protein

Bai

Yang

Chung

et al. 2001

J of Applied Polymer Sci

View full text Add to dashboard Cite

ABSTRACT:Eight kinds of self-catalyzed poly(ortho-esters) (POEs) are used to fabricate bovine serum albumin (BSA)-containing microspheres using a W/O/W double-emulsion solvent extraction/evaporation method. All eight kinds of POE polymers used in this study are shown able to form microspheres under proposed fabrication conditions. The surface morphology and inner structure of the microspheres are analyzed using scanning electron microscopy (SEM). The microspheres have a size range from 64.7 to 120.2 m. POE with a higher viscosity leads to bigger microspheres. It was found that the POE composition has a significant effect on BSA release profiles. POEs, which are more hydrophilic and contain a greater amount of glycolide or lactate (latent acid), yield higher BSA release rates. Specifically, POE containing 1,6-hexanediol diglycolide (HDdiGL) microspheres have the highest BSA release rate after a 20-day test through a combination of surface erosion and diffusion mechanisms. POE containing a high percentage of the trans-cyclohexanedimethanol (CDM) segment tends to yield microspheres with a lower release rate because of its hydrophobic nature. It was also found that the BSA release rate is more rapid at 37°C than at 22°C because of faster polymer degradation and water penetration at 37°C. Experimental results suggest that various protein release rates can be achieved by using different compositions of POEs.

show abstract

Section: Introductionmentioning

confidence: 99%

Effect of polymer compositions on the fabrication of poly(ortho‐ester) microspheres for controlled release of protein

Bai

Yang

Chung

et al. 2001

J of Applied Polymer Sci

View full text Add to dashboard Cite

show abstract

“…In order to provide a delivery device displaying a zero order drug release rate, many efforts have been made to create controlled release systems using polymers such as polylactide [1][2][3], silicone-rubber [4], poly(ortho ester) [5], albumin [6,7] and fibrinogen [8]. Recently, new types of drug delivery systems which can control drug release in response to a physical, biological or chemical signal such as pH [9,10], temperature [11][12][13], microwave irradiation [14], magnetism [15], and blood sugar [16,17] have been investigated.…”

Section: Introductionmentioning

confidence: 99%

Thermo-Sensitive Release Behavior of 5-Fluorouracil from Chitosan-Gel Microspheres Coated with Lipid Multilayers

Ohya

Takei

Ouchi

1992

Journal of Bioactive and Compatible Polymers

View full text Add to dashboard Cite

In order to provide a device that would release anticancer drugs in response to temperature, chitosan microspheres with immobilized 1-[N-(5- aminopentyl)urea]-5-fluorouracil (Ap-5FU) and coated with dipalmitoyl phosphatidyl choline (DPPC) multilayers were prepared. The chitosan-DPPC- chitosan microspheres were prepared by coating chitosan-DPPC microspheres with polyelectrolyte complex membrane of chitosan. Good distributive stability of microspheres in aqueous solution was achieved with the DPPC multilayers coating. When chitosan was crosslinked with glutaraldehyde, Ap-5FU was si multaneously immobilized to the microspheres by means of Schiffs base forma tion. In physiological saline media, free 5FU released from the microspheres was detected, but the 5FU derivative was not. The release rate of 5 FU from the microspheres was decreased by coating with DPPC multilayers, and further depressed by the formation of polyelectrolyte complex membrane. The thermo- sensitive release behavior of 5FU from chitosan-DPPC microspheres and chitosan-DPPC-chitosan microspheres was observed in vitro across the phase transition temperature ( T m) of the DPPC multilayer (41.4 ° C).

show abstract

“…In order to increase the delivery effects, excipients that preserve the protein in its preferred state of hydration were also used to stabilize the protein in these nonconventional routes. Several studies 62,[65][66] - 75 , which have been proposed for the sustained delivery of several therapeutic classes, including: contraceptive steroid 76 , peptide hormone 77,78 , prostaglandins 79 , narcotic antagonists 80 , anti-arrhythmics 81 and anti-cancer agents 82 . Although the therapeutic potential for implant systems is immense, the commercialization of these systems has been limited mainly by the difficulty of administration, i.e., needing surgical incision for implanting, and in some cases explanting, which raises medical costs; patient discomfort is another factor that has limited the widespread use of pre-formed implant devices.…”

mentioning

confidence: 99%

Study of injectable depots for drug delivery

Wang¹

View full text Add to dashboard Cite

bovine serum albumin and chicken egg lysozyme) quantified by size exclusion chromatography (SEC) and bicinchoninic acid (BCA) protein assay, especially in the later stage, indicating PLGA hydrolysis-induced instability of proteins. Protein drug also displays incomplete release. Low molecular weight neutral salts such as sodium chloride, or sugar such as glucose and sucrose can increase the release rate and completeness of release by several times, while additives that accelerate PLGA degradation have little effect.

show abstract

Controlled release of 5-fluorouracil from linear poly(ortho esters)

Cited by 24 publications

References 14 publications

Effect of polymer compositions on the fabrication of poly(ortho‐ester) microspheres for controlled release of protein

Effect of polymer compositions on the fabrication of poly(ortho‐ester) microspheres for controlled release of protein

Thermo-Sensitive Release Behavior of 5-Fluorouracil from Chitosan-Gel Microspheres Coated with Lipid Multilayers

Study of injectable depots for drug delivery

Contact Info

Product

Resources

About