Degradation behaviour of microspheres prepared by spray-drying poly(d,l-lactide) and poly(d,l-lactide-co-glycolide) polymers

Blanco, Marcos; Sastre, R.; Teijón, César; Olmo, Rosa; Teijón, José M.

doi:10.1016/j.ijpharm.2006.07.030

Cited by 67 publications

(38 citation statements)

References 24 publications

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“…The morphology of SDM-Ms after degradation was studied by optical microscope. Meanwhile, the Prout-Tompkins equation [17] and mass loss (ML) were determined for studying the degree of degradation based on the following equations:…”

Section: In Vitro Degradationmentioning

confidence: 99%

Soluble starch–based biodegradable and microporous microspheres as potential adsorbent for stabilization and controlled release of coix seed oil

Peng

Xiong

Wang

et al. 2011

Eur Food Res Technol

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Soluble starch-based biodegradable and microporous microspheres (SDM-Ms) were prepared by emulsion chemical cross-linking technique using trisodium trimetaphosphate (TSTP) as the cross-linker. The resultant amorphous SDM-Ms were excellently identified by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). The internal rupture and surface-controlled erosion were the predominant degradation mechanisms for SDM-Ms. The obtained SDM-Ms were applied to adsorb coix seed oil (CSO) by immersing method. The adsorption capacity of CSO within SDM-Ms was determined, namely 0.5238 g/g, and the thermal stability was shown higher than that of the free CSO. A burst release appeared in the second hour, followed by controlled release. Diffusion, degradation, and erosion mechanisms might coexist for the full release processes. The soluble starch (Ss) was demonstrated a promising biodegradable polymer for preparing the porous microspheres. Meanwhile, after being adsorbed into the SDM-Ms, the CSO can be powerfully applied in food and pharmaceutical industries.

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Section: In Vitro Degradationmentioning

confidence: 99%

Soluble starch–based biodegradable and microporous microspheres as potential adsorbent for stabilization and controlled release of coix seed oil

Peng

Xiong

Wang

et al. 2011

Eur Food Res Technol

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“…To observe the porous structure of PLGA/b-TCP scaffolds before and after the incorporation of microspheres and after the release of Dex and BSA, the samples were frozen-fractured in liquid nitrogen and gold-coated. Relative molecular mass of PLGA in the PLGA-Dex microspheres before and after releasing for different times (7,18,29, and 50 days) was determined by gel permeation chromatography (GPC, Agilent 1100) equipped with a refractive index detector in tetrahydrofuran. The vacuum-dried samples were dissolved in tetrahydrofuran in a 4 mg/mL concentration and filtrated with a 0.22-lm filter.…”

Section: Characterizationsmentioning

confidence: 99%

Controllable dual‐release of dexamethasone and bovine serum albumin from PLGA/β‐tricalcium phosphate composite scaffolds

et al. 2010

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Localized dual-drug delivery from biodegradable scaffolds is an important strategy in tissue engineering. In this study, porous poly(L-lactide-co-glycolide) (PLGA)/β-tricalcium phosphate scaffolds containing both dexamethasone (Dex) and bovine serum albumin (BSA) were prepared by incorporating Dex-loaded and BSA-loaded microspheres into the scaffolds. PLGA microspheres containing Dex or BSA were prepared by spray-drying and double emulsion/solvent evaporation, respectively. In vitro release studies indicated that microspheres prepared from PLGA in 3:1 molar ratio of L-lactide/glycolide and 89.5 kDa relative molecular mass showed prolonged release profiles compared with those prepared from PLGA in 1:1 L-lactide/glycolide molar ratio and 30.5 kDa relative molecular mass. Additionally, introduction of poly(ethylene glycol) in the PLGA chain could improve the encapsulation efficiency and reduce the release rate. Based on the above results, controllable dual-release of Dex and BSA with relatively higher or lower release rate was achieved by incorporating Dex-loaded and BSA-loaded microspheres with different release profiles into the PLGA/β-tricalcium phosphate scaffolds.

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“…Chain cleavage continues, along with increasing porosity, until molecular weights of these shorter-chain products reach critical values that allow for their dissolution in the aqueous medium. Diffusion starts within the whole bulk, until the trapped, more-soluble, acidic moieties are released to the surrounding aqueous medium (40)(41)(42). At this point, the medium pH starts to drop.…”

Section: Microsphere Degradationmentioning

confidence: 99%

“…It was found that Tg started to decrease markedly after 20 days of experiment, to reach a value of 42.9°C by the 35th day, compared with 53.8°C before the experiment. This lowering in Tg values can be attributed to the plasticizing effect of water on PLGA (40,41,43) that caused a physical-state transition of the PLGA matrix into an elastic solid mass (43). This facilitated further drop in the average molecular weight, along with a consequent increase in the macromolecular mobility (44).…”

Section: Microsphere Degradationmentioning

confidence: 99%

Prednisolone-Loaded PLGA Microspheres. In Vitro Characterization and In Vivo Application in Adjuvant-Induced Arthritis in Mice

et al. 2010

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Abstract. This study aimed at preparation of a sustained-release steroidal treatment for chronic inflammatory conditions, such as rheumatoid arthritis. To achieve such a goal, biodegradable polylactide-co-glycolide prednisolone-loaded microspheres were prepared using o/w emulsion solvent evaporation method. Formulation parameters were adjusted so as to optimize the microsphere characteristics. The prepared microspheres exhibited smooth and intact surfaces, with average size range not exceeding 65 µm. The encapsulation efficiency percent of most microsphere formulations fell within the range of 25-68%. Drug release from these microspheres took place over 4 weeks, with nearto-zero-order patterns. Two successful formulations were chosen for the treatment of unilateral arthritis, induced in mice using Freund's complete adjuvant (FCA). Inflammatory signs of adjuvant arthritis included severe swelling of the FCA-injected limbs, in addition to many histopathological lesions. These included inflammatory cell infiltration, synovial hyperplasia, cartilage, and bone erosion. Parenteral administration of the selected formulae dramatically reduced the swelling of the FCA-injected limbs. In addition, histological examination revealed that the microsphere treatment protocol efficiently protected cartilages and bones of mice, injected with FCA initial and booster doses, from erosion. These results could not be achieved by a single prednisolone dose of 5 mg/kg.

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Degradation behaviour of microspheres prepared by spray-drying poly(d,l-lactide) and poly(d,l-lactide-co-glycolide) polymers

Cited by 67 publications

References 24 publications

Soluble starch–based biodegradable and microporous microspheres as potential adsorbent for stabilization and controlled release of coix seed oil

Soluble starch–based biodegradable and microporous microspheres as potential adsorbent for stabilization and controlled release of coix seed oil

Controllable dual‐release of dexamethasone and bovine serum albumin from PLGA/β‐tricalcium phosphate composite scaffolds

Prednisolone-Loaded PLGA Microspheres. In Vitro Characterization and In Vivo Application in Adjuvant-Induced Arthritis in Mice

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