Topical use of chitosan in ophthalmology: tolerance assessment and evaluation of precorneal retention

Felt, O.; Furrer, Pascal; Mayer, Joachim M.; Plazonnet, Bernard; Buri, P; Gurny, Robert

doi:10.1016/s0378-5173(99)00003-4

Cited by 333 publications

(142 citation statements)

References 17 publications

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“…In the present study, we used the same types of chitosans as were previously used by Felt et al 4 . More precisely, 2 high purity grade chitosan salts of similar deacetylation degree (>80%) were purchased from Pronova Biopolymer (Oslo, Norway), namely chitosan hydrochloride UPCl 110 and chitosan glutamate UPG 210, which have the molecular weights of 160 kd and 580 kd, respectively.…”

Section: Methodsmentioning

confidence: 99%

“…In a previous study 4 , it was demonstrated by gamma scintigraphy that the presence of chitosan in an ophthalmic solution always resulted in a significant increase of the precorneal residence time when compared with commercial controls, regardless of the type of polysaccharide or of its concentration in the formulation. Hence, a corresponding increase of drug concentration in tears could be expected, based on the general hypothesis that prolonging precorneal residence time enables therapeutic drug levels to be maintained over longer periods of time.…”

Section: Lachrymal Availability Of Tobramycin and Ofloxacinmentioning

confidence: 99%

“…The aim of this study was to compare the performance of chitosan-based formulations with that of commercially available ophthalmic solutions, namely Tobrex® (Alcon, Fort Worth, TX) and Floxal® (Chauvin, Montpellier, France), and to determine whether increased corneal contact time due to the presence of a viscosifying and bioadhesive vehicle such as chitosan, as previously demonstrated 4 , can be correlated with prolonged concentrations of drugs in tears.…”

Section: Introductionmentioning

confidence: 99%

“…Indeed, an ophthalmic formulation that increases the contact time with the ocular surface should allow therapeutic levels to be maintained over a prolonged period of time. Chitosan was chosen as a vehicle to increase tobramycin and ofloxacin concentrations in ocular fluids because this biodegradable polysaccharide has been demonstrated to remain in the precorneal area significantly longer than a commercial solution 4 .…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Delivery of antibiotics to the eye using a positively charged polysaccharide as vehicle

Felt

Gurny

Baeyens³

2001

AAPS PharmSci

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The positively charged polysaccharide chitosan is able to increase precorneal residence time of ophthalmic formulations containing active compounds when compared with simple aqueous solutions. The purpose of the study was to evaluate tear concentration of tobramycin and ofloxacin after topical application of chitosan-based formulations containing 0.3% wt/vol of antibiotic and to compare them with 2 commercial solutions: Tobrex® and Floxal®, respectively. The influence of the molecular weight, deacetylation degree, and concentration of 4 different samples of chitosan on pharmacokinetic parameters (area under the curve values [AUC eff ] and time of efficacy [t eff ]) of tobramycin and ofloxacin in tears was investigated over time. It was demonstrated that the 2 chitosan products of high molecular weight (1350 and 1930 kd) and low deacetylation degree (50%) significantly increased antibiotic availability when compared to the controls, with AUC eff showing a 2-to 3-fold improvement. The time of efficacy of ofloxacin was significantly increased from about 25 minutes to 46 minutes by the chitosan of higher Mw (1930 kd) at a concentration of 0.5% wt/vol, whereas a similar performance was achieved by a chitosan of low Mw (580 kd) at a concentration of 1.5% wt/vol in the case of tobramycin.

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Section: Methodsmentioning

confidence: 99%

Section: Lachrymal Availability Of Tobramycin and Ofloxacinmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Delivery of antibiotics to the eye using a positively charged polysaccharide as vehicle

Felt

Gurny

Baeyens³

2001

AAPS PharmSci

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“…Oküler ilaçların etkinliğini artırmada polimer esaslı hidrojeller kullanarak ilacın perikorneal alandaki bulunma süresi artırılmaktır. 2,66 Kitozan kalp damar cerrahisinde, sütür materyallerinde ve yanık tedavisinde kullanılmaktadır. 5,67,68 Kitozanın klinik amaçlarla kullanımında; sterilizasyon yöntemi olarak iyonizasyon ışıması (γ radyasyonu), kuru hava, doymuş buhar ve kimyasal ajanlar (etilen oksit, etanol vb) kullanılmaktadır.…”

Section: Kitozanın Biyomedikal Ve Farmasötik Uygulamalarıunclassified

Di̇ş Heki̇mli̇ği̇nde Ki̇ti̇n Ve Ki̇tozan

Oyar¹

2015

Atatürk Üniversitesi Diş Hekimliği Fakültesi Dergisi

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Liposomes and Drug Delivery

Antimisiaris

Kallinteri

Fatouros³

2010

Pharmaceutical Sciences Encyclopedia

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Liposomes are vesicles in which an aqueous volume is entirely surrounded by a phospholipid membrane and their size can range between 30 and 50 nm up to several micrometers. Liposomes serve as a drug delivery system because of their versatile structure and because they are nontoxic, nonimmunogenic, and fully biodegradable. This chapter focuses on basic characteristics and applications of liposomes, their fate after in vivo administration by different routes, and other possible routes for in vivo administration of liposomes.

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Topical use of chitosan in ophthalmology: tolerance assessment and evaluation of precorneal retention

Cited by 333 publications

References 17 publications

Delivery of antibiotics to the eye using a positively charged polysaccharide as vehicle

Delivery of antibiotics to the eye using a positively charged polysaccharide as vehicle

Di̇ş Heki̇mli̇ği̇nde Ki̇ti̇n Ve Ki̇tozan

Liposomes and Drug Delivery

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