Novel preparation of enteric-coated chitosan-prednisolone conjugate microspheres and in vitro evaluation of their potential as a colonic delivery system

Oosegi, Tomoko; Onishi, Hiraku; Machida, Yoshiharu

doi:10.1016/j.ejpb.2007.06.016

Cited by 46 publications

(16 citation statements)

References 11 publications

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“…From such knowledge, PD-loaded microparticles have been developed using chitosan-suscinyl-predinisolone conjugate and enteric-coating polymer, Eudragit [23] [24]. Before now, Eudragit L-coated conjuagte microparticles (MP/EuL) were evaluated for pharmacological and pharmacokinetic features [25] [26].…”

Section: Introductionmentioning

confidence: 99%

Pharmacokinetic Evaluation of Chitosan-Succinyl-Prednisolone Conjugate Microparticles as a Colonic Delivery System: Comparison with Enteric-Coated Conjugate Microparticles

Onishi¹

2014

Health

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In the previous study, chitosan-succinyl-prednisolone conjugate microparticles (MP) were found to exhibit good efficacy and reduced toxicity nearly as well as their Eudragit L-coated microparticles (MP/EuL). This proposes a question whether enteric-coating of MP is necessary or not. Although MP/EuL were already examined for their pharmacokinetic and gastrointestinal behaviors, MP have not been done yet. Therefore, in this study, MP were evaluated by investigating pharmacokinetic features in detail. MP with the in vitro features equivalent to those of the previous conjugate microparticles could be produced more readily in the modified preparative method. Pharmacokinetic and gastrointestinal behaviors of MP were investigated by intragastric dosing (5 mg PD eq./kg) to rats with 2,4,6-trinitrobenzenesulfonic acid-induced ulcerative colitis. The plasma concentration was suppressed extensively in MP as well as MP/EuL, supporting the reduction of PD systemic toxic side effects. However, the plasma level increased gradually up to 7 h in MP, but not in MP/EuL. At 8 h after dosing, MP were detected in the stomach to a fair extent, and free PD was found there, indicating that MP were subjected to trapping in the stomach probably due to positive charge of chitosan molecules. For MP, such prolonged localization and slow release of PD in the stomach were probably associated with the gradual increase in plasma concentration. Therefore, MP/EuL were evaluated to be superior to MP for effective targeting to ulcerative colitis. It is concluded that enteric-coating is very important for the targeting system using MP.

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Section: Introductionmentioning

confidence: 99%

Pharmacokinetic Evaluation of Chitosan-Succinyl-Prednisolone Conjugate Microparticles as a Colonic Delivery System: Comparison with Enteric-Coated Conjugate Microparticles

Onishi¹

2014

Health

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“…The effects of these parameters were investigated by many researchers. For instance, the sonication power usually controls the particle size (Kabir, Saha, & Jeelani, 2007;Kang et al, 2006;Oosegi, Onishi, & Machida, 2008).…”

Section: Microparticle Size and Zeta Potentialmentioning

confidence: 99%

Chitosan microparticles loaded with exotoxin A subunit antigen for intranasal vaccination against Pseudomonas aeruginosa: An in vitro study

Taranejoo

Rafienia

Kamali³

et al. 2011

Carbohydrate Polymers

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“…The in vitro release studies revealed that no SD was released at the gastric pH; however, when the microsphere reached the colonic environment, a continuous release was observed for a variable time (8-12 h). In a similar study, Onishi et al prepared Eudragit®-coated microspheres composed of chitosan-succinylprednisolone conjugates (Ch-SP) using the sonication method [38]. These authors demonstrated that Eudragit®-coated microspheres protected the Ch-SP microspheres from morphological changes at pH 1.2, and regenerated them at pH 6.8 and 7.4.…”

Section: Introductionmentioning

confidence: 98%

Chitosan Mediated Targeted Drug Delivery System: A Review

Patel¹,

Patel²,

Patel³

2010

J Pharm Pharm Sci

233

166

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-Chitosan has prompted the continuous movement for the development of safe and effective drug delivery systems because of its unique physicochemical and biological characteristics. The primary hydroxyl and amine groups located on the backbone of chitosan allow for chemical modification to control its physical properties. When the hydrophobic moiety is conjugated to a chitosan molecule, the resulting amphiphile may form self-assembled nanoparticles that can encapsulate a quantity of drugs and deliver them to a specific site of action. Chemical attachment of the drug to the chitosan throughout the functional linker may produce useful prodrugs, exhibiting the appropriate biological activity at the target site. Mucoadhesive and absorption enhancement properties of chitosan increase the in vivo residence time of the dosage form in the gastrointestinal tract and improve the bioavailability of various drugs. The main objective of this review is to provide an insight into various target-specific carriers, based on chitosan and its derivatives. The first part of the review is concerned with the organ-specific delivery system using chitosan and its derivatives. The subsequent section considers the recent developments of drug delivery carriers for cancer therapy with special focus on various targeting strategies. __________________________________________________________________________________________

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Novel preparation of enteric-coated chitosan-prednisolone conjugate microspheres and in vitro evaluation of their potential as a colonic delivery system

Cited by 46 publications

References 11 publications

Pharmacokinetic Evaluation of Chitosan-Succinyl-Prednisolone Conjugate Microparticles as a Colonic Delivery System: Comparison with Enteric-Coated Conjugate Microparticles

Pharmacokinetic Evaluation of Chitosan-Succinyl-Prednisolone Conjugate Microparticles as a Colonic Delivery System: Comparison with Enteric-Coated Conjugate Microparticles

Chitosan microparticles loaded with exotoxin A subunit antigen for intranasal vaccination against Pseudomonas aeruginosa: An in vitro study

Chitosan Mediated Targeted Drug Delivery System: A Review

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