Alginate Inserts Loaded with Epidermal Growth Factor for the Treatment of Keratoconjunctivitis Sicca

Koelwel, Christoph; Rothschenk, Stefan; Fuchs-Koelwel, B; Gabler, Bernhard; Lohmann, Chris P.; Göpferich, Achim

doi:10.1080/10837450801949566

Cited by 20 publications

(9 citation statements)

References 18 publications

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“…Reservoir inserts consist of a central reservoir of drug enclosed in a specially designed semipermeable or microporous membrane, which allows the drug to diffuse from the reservoir at a predetermined zero-order release rate (e.g., Ocusert). Reservoir-controlled release systems may be manufactured in a wide range of geometries, including conventional tablets/pellets, laminated films, and other defined shapes (e.g., hemispheres, cylinders, or rods) using, for example, ALG [100][101][102] and cellulose as polymeric materials [103].…”

Section: Inserts and Contact Lensesmentioning

confidence: 99%

Polysaccharides in Ocular Drug Delivery

et al. 2019

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Polysaccharides, such as cellulose, hyaluronic acid, alginic acid, and chitosan, as well as polysaccharide derivatives, have been successfully used to augment drug delivery in the treatment of ocular pathologies. The properties of polysaccharides can be extensively modified to optimize ocular drug formulations and to obtain biocompatible and biodegradable drugs with improved bioavailability and tailored pharmacological effects. This review discusses the available polysaccharide choices for overcoming the difficulties associated with ocular drug delivery, and it explores the reasons for the dependence between the physicochemical properties of polysaccharide-based drug carriers and their efficiency in different formulations and applications. Polysaccharides will continue to be of great interest to researchers endeavoring to develop ophthalmic drugs with improved effectiveness and safety.

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Section: Inserts and Contact Lensesmentioning

confidence: 99%

Polysaccharides in Ocular Drug Delivery

et al. 2019

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“…A possible explanation for this observation is the difference in the swelling and erosion behavior between the different viscosity grades of sodium alginate. The low-viscosity-grade alginate contains polymers with shorter chain length with respect to medium viscosity grade alginate, which could result in a looser network and correspondingly less restriction to water acceptability and thus faster swelling and erosion of the polymeric matrix which facilitate rapid solute movement (13). It is reported that the increase in polymer molecular weight is usually coupled with an increase in the entanglement of the polymer macromolecules accompanied by a decrease in polymer dissolution rate.…”

Section: In Vitro Drug Release Studiesmentioning

confidence: 99%

“…In spite of the numerous advantages demonstrated by ocular inserts, its capital disadvantage is the foreign body sensation accompanied with its initial administration (13). After which, it exhibits a gelling behavior, resulting in an extended residence at the site of drug action.…”

Section: Introductionmentioning

confidence: 99%

Biodegradable Ocular Inserts for Sustained Delivery of Brimonidine Tartarate: Preparation and In Vitro/In Vivo Evaluation

2011

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The bioavailability of therapeutic agents from eye drops is usually limited due to corneal barrier functions and effective eye protective mechanisms. Therefore, the current study aims to enhance ocular bioavailability of brimonidine, a potent antiglaucoma drug, through the preparation of ocular inserts. Solvent casting technique was employed to prepare the inserts using polyvinylpyrrolidone K-90 (PVP K-90) as film-forming polymer blended with different viscosity grades of bioadhesive polymers namely hydroxypropyl methycellulose, carbopol, sodium alginate, and chitosan. The prepared ocular inserts were evaluated for various physicochemical parameters, swelling behavior, and in vitro release patterns. Sodium alginate-based ocular inserts revealed the most sustainment in drug release (99% at 6 h), so it was selected for further modifications via coating it, on one side or dual sides, using hydrophobic film composed of either ethylcellulose or Eudragit RSPO. The obtained in vitro release results for the modified ocular inserts revealed that ethylcellulose is superior to Eudragit RSPO in terms of brimonidine release sustainment effect. Ocular inserts composed of 7% PVP K-90, 1.5% low molecular weight sodium alginate with or without ethylcellulose coat were able to sustain the in vitro release of brimonidine. Their therapeutic efficacy regarding intraocular pressure (IOP) lowering effect when inserted in albino rabbits eyes showed superior sustainment effect compared with that of brimonidine solution. Furthermore, due to both the mucoadhesive property and the drug sustainment effect, the one-side-coated ocular insert showed more IOP lowering effect compared with that of its non-coated or dual-side-coated counterpart.

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“…However, the accuracy and technical applicability of the film preparation methods were still quite different. In our earlier work and other described procedures,19–21 alginate films were cross‐linked by spraying or even dipping them in a solution of calcium lactate or other soluble calcium salts. Using these methods, calcium is not distributed evenly all over the film and, more importantly, the absolute content of the incorporated cross‐linker cannot be controlled, but is the result of diffusion and equilibrium between the film and the calcium solution.…”

Section: Resultsmentioning

confidence: 99%

Preparation of well‐defined calcium cross‐linked alginate films for the prevention of surgical adhesions

Esser

Teßmar

2013

J Biomed Mater Res

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Abdominal adhesions are one of the major problems associated with abdominal surgeries or abdominal trauma. There are many different therapeutic options to prevent these adhesions, for example, the application of barrier films made of biodegradable polymers like alginate. For many application relevant parameters (mechanical stability, elasticity, erosion, and mucoadhesivity of the films), the extent of cross-linking with divalent cations, such as calcium, is essential to obtain alginate films with clinically ideal properties. All these properties can eventually be strongly influenced by the composition of the films. For this reason, the manufacture of thin films (≈20 µm) was improved to accurately control the calcium content and distribution as well as the time and process of cross-linking. The aim of this work was to find the best suited method to evenly distribute the calcium ions in the alginate films and to obtain films with controlled erosion times as well as sufficient flexibility and stability. Furthermore, the influence of plasticizers on the mechanical stability and elasticity was tested to find the amount and type of plasticizers that have to be added to produce the best suited films.

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Alginate Inserts Loaded with Epidermal Growth Factor for the Treatment of Keratoconjunctivitis Sicca

Cited by 20 publications

References 18 publications

Polysaccharides in Ocular Drug Delivery

Polysaccharides in Ocular Drug Delivery

Biodegradable Ocular Inserts for Sustained Delivery of Brimonidine Tartarate: Preparation and In Vitro/In Vivo Evaluation

Preparation of well‐defined calcium cross‐linked alginate films for the prevention of surgical adhesions

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