Pharmaceutical Dosage Form Design of Copoly (Lactic/Glycolic Acid) Microspheres. Mechanism of in Vitro Release of Gentamicin

Nagata, Shunji; Takeshima, Kazuo; Hirano, Koichiro; Takagishi, Yasushi

doi:10.1248/yakushi1947.114.12_1005

Cited by 5 publications

(3 citation statements)

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“…It has been shown that changing the dispersion medium from an aqueous solution to an oily medium improved the encapsulation efficiency of tyrotropin‐releasing hormone into PLGA nanospheres from 3% to 40% 62. Nagata et al observed that the terminal free carboxyl group of the polymer (the same type of PLGA was used in our study) is necessary for efficient gentamicin sulfate entrapment in PLGA microspheres 63. For the highly water soluble leuprorelin, NMR measurements recently showed that a rigid structure is formed in the microspheres due to ionic interaction between amino groups of the drug and the terminal carboxylic anions of the polymer 64.…”

Section: Resultsmentioning

confidence: 53%

A Novel Approach to Prepare Insulin-Loaded Poly (Lactic-Co-Glycolic Acid) Microcapsules and the Protein Stability Study

Emami

Hamishehkar

Najafabadi

et al. 2009

Journal of Pharmaceutical Sciences

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Section: Resultsmentioning

confidence: 53%

A Novel Approach to Prepare Insulin-Loaded Poly (Lactic-Co-Glycolic Acid) Microcapsules and the Protein Stability Study

Emami

Hamishehkar

Najafabadi

et al. 2009

Journal of Pharmaceutical Sciences

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“…Also, the haloperidol incorporation values for capped PLGA 50:50 (~8%) and capped PLGA 95:5 (~12%) are comparable, thus indicating that the L:G ratio is less important than the endgroups. The importance of endgroups has previously been suggested for PLGA microspheres loaded with the drugs gentamicin (Nagata S, 1994) and leuprorelin (Takada S, 1998). There is also a report for PLGA nanoparticles in which the end group doubles the protein loading (Gaspar M M, 1998).…”

Section: Drug Incorporation Efficiency and Drug Contentmentioning

confidence: 98%

Production of haloperidol-loaded PLGA nanoparticles for extended controlled drug release of haloperidol

Budhian¹,

Siegel²,

Winey

2005

Journal of Microencapsulation

122

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. (2005). Production of haloperidol loaded PLGA nanoparticles for extended controlled drug release of haloperidol. Retrieved from http://repository.upenn.edu/mse_papers/149Production of haloperidol loaded PLGA nanoparticles for extended controlled drug release of haloperidol AbstractThis study developed an emulsion-solvent evaporation method for producing haloperidol-loaded PLGA nanoparticles with up to 2% (wt/wt. of polymer) drug content, in vitro release duration of over 13 days and less than 20% burst release. The free haloperidol is removed from the nanoparticle suspension using a novel solid phase extraction technique. This leads to a more accurate determination of drug incorporation efficiency than the typical washing methods. It was discovered that PLGA end groups have a strong influence on haloperidol incorporation efficiency and its release from PLGA nanoparticles. The hydroxyl-terminated PLGA (uncapped) nanoparticles have a drug incorporation efficiency of more than 30% as compared to only 10% with methyl-terminated PLGA (capped) nanoparticles. The in vitro release profile of nanoparticles with uncapped PLGA has a longer release period and a lower initial burst as compared to capped PLGA. By varying other processing and materials parameters, the size, haloperidol incorporation and haloperidol release of the haloperidol-loaded PLGA nanoparticles were controlled. AbstractWe have developed an emulsion-solvent evaporation method for producing haloperidol loaded PLGA nanoparticles with up to 2 % (wt/wt. of polymer) drug content, in-vitro release duration of over 13 days and less than 20% burst release. The free haloperidol is removed from the nanoparticle suspension using a novel solid phase extraction technique. This leads to a more accurate determination of drug incorporation efficiency than the typical washing methods. We have discovered that PLGA end groups have a strong influence on haloperidol incorporation efficiency and its release from PLGA nanoparticles. The hydroxyl terminated PLGA (uncapped) nanoparticles have a drug incorporation efficiency of more than 30% as compared to only 10% with methyl terminated PLGA (capped) nanoparticles. The in-vitro release profile of nanoparticles with uncapped PLGA has a longer release period and a lower initial burst as compared to capped PLGA. By varying other processing and materials parameters, we also controlled the size, haloperidol incorporation and haloperidol release of our haloperidol loaded PLGA nanoparticles.3

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“…For example, NPs made of COOH terminated PLGA polymer were found to have three times higher incorporation efficiency of Haloperidol compared to the ester terminated ones [17]. The influence of PLGA end groups on the encapsulation efficiency of several drugs such as gentamicin [19], and leuprorelin [20], as well as proteins [21], has been documented. The end group of PLGA is also shown to affect the release kinetics of encapsulated drugs from NPs [17,22].…”

Section: Introductionmentioning

confidence: 99%

Immunoadjuvant activity of the nanoparticles’ surface modified with mannan

et al. 2014

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Mannan (MN) is the natural ligand for mannose receptors, which are widely expressed on dendritic cells (DCs). The purpose of this study was to assess the effect of formulation parameters on the immunogenicity of MN-decorated poly (D, L-lactide-co-glycolide) (PLGA) nanoparticles (NPs) in terms of their ability to stimulate DC phenotypic as well as functional maturation. For this purpose, NPs were formulated from either ester-terminated or COOH-terminated PLGA. Incorporation of MN in NPs was achieved through encapsulation, physical adsorption or chemical conjugation. Murine bone marrow derived DCs (BMDCs) were treated with various NP formulations and assessed for their ability to up-regulate DC cell surface markers, secrete immunostimulatory cytokines and to activate allogenic T cell responses. DCs treated with COOH-terminated PLGA-NPs containing chemically conjugated MN (MN-Cov-COOH) have shown superior performance in improving DC biological functions, compared to the rest of the formulations tested. This may be attributed to the higher level of MN incorporation in the former formulation. Incorporation of MN in PLGA NPs through chemical conjugation can lead to enhanced DC maturation and stimulatory function. This strategy may be used to develop more effective PLGA-based vaccine formulations.

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Pharmaceutical Dosage Form Design of Copoly (Lactic/Glycolic Acid) Microspheres. Mechanism of in Vitro Release of Gentamicin

Cited by 5 publications

References 0 publications

A Novel Approach to Prepare Insulin-Loaded Poly (Lactic-Co-Glycolic Acid) Microcapsules and the Protein Stability Study

A Novel Approach to Prepare Insulin-Loaded Poly (Lactic-Co-Glycolic Acid) Microcapsules and the Protein Stability Study

Production of haloperidol-loaded PLGA nanoparticles for extended controlled drug release of haloperidol

Immunoadjuvant activity of the nanoparticles’ surface modified with mannan

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