Ethylcellulose

Coating agent flavoring fixative tablet binder tablet filler viscosity-increasing agent. 

Ethylcellulose is widely used in oral and topical pharmaceutical formulations see Table I. 

The main use of ethylcellulose in oral formulations is as a hydrophobic coating agent for tablets and granules. Ethylcellulose coatings are used to modify the release of a drug, to mask an unpleasant taste, or to improve the stability of a formulation for example, where granules are coated with ethylcellulose to inhibit oxidation. Modified-release tablet formulations mav also be produced using ethylcellulose as a matrix former.  

Ethylcellulose, dissolved in an organic solvent or solvent mixture, can be used on its own to produce water-insoluble films. Higher-viscosity ethylcellulose grades tend to produce 

High-viscosity grades of ethylcellulose are used in drug microencapsulation. 20-22) 

By introduction into cellulose of about 0.5 equivalent of methyl or ethyl groups a product is readily obtained which can be dissolved in alkali of 4-10%. The ether may be regenerated from this solution by 

Peak Notation Assignment of Main Peaks Molecular Weight Retention Index Relative Intensity 

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Similarly, ethylene oxide and 1,2-butylene oxide are used to make methyUiydroxy-ethylcellulose and methyUiydroxybutylcellulose, respectively. 

Specifications and Standards Test Methods. Ethylcellulose is cleared foi many apphcations in food and food contact under the Eedeial Eood, Dmg, and Cosmetic Act, as amended. Examples include binder in dry vitamin preparations for animal feed, coatings and inks for paper and paperboard products used in food packaging, and closures with sealing gaskets for food containers (44). Methods of analyses ate given in ASTM D914-72 (19), NationalFonmila XIV, and Food Chemicals Codex II. 

Some tablets combine sustained-release and rapid disintegration characteristics. Products such as K-Dur (Key Pharmaceuticals) combine coated potassium chloride crystals in a rapidly releasing tablet. In this particular instance, the crystals are coated with ethylcellulose, a water-insoluble polymer, and are then incorporated into a rapidly disintegrating microcrystalline cellulose (MCC) matrix. The purpose of this tablet is to minimize GI ulceration, commonly encountered by patients treated with potassium chloride. This simple but elegant formulation is an example of a solid dosage form strategy used to achieve clinical goals. 

Ethylcellulose EC Ethanol, other organic solvents Cannot be used alone as is totally insoluble in water and GI fluids employed as a film toughner... 

An improvement in this system is to coat the ion-exchange resin with a hydrophobic rate-limiting polymer, such as ethylcellulose or wax [43], These systems rely on the polymer coat to govern the rate of drug availability. 

Ethylcellulose 225 (mean) Arterial cheamoembolism for delivery of cytostatics to kidney and liver Mitomycin... 

Ferromagnetic ethylcellulose 307 Extracorporeal guidance to tumors Mitomycin... 

The formation of ethylcellulose nanoemulsions by a low-energy method for nanoparticle preparation was reported recently. The nanoemulsions were obtained in a water-polyoxyethylene 4 sorbitan monolaurate-ethylcellulose solution system by the PIC method at 25 °C [54]. The solvent chosen for the preparation of the ethylcellulose solution was ethyl acetate, which is classed as a solvent with low toxic potential (Class 3) by ICH Guidelines [78]. Oil/water (O/W) nanoemulsions were formed at oil/ surfactant (O/S) ratios between 30 70 and 70 30 and water contents above 40 wt% (Figure 6.1). Compared with other nanoemulsions prepared by the same method, the O/S ratios at which they are formed are high, that is, the amount of surfactant needed for nanoemulsion preparation is rather low [14]. For further studies, compositions with volatile organic compound (VOC) contents below 7 wt% and surfactant concentrations between 3 and 5 wt% were chosen, that is, nanoemulsions with a constant water content of 90% and O/S ratios from 50 50 to 70 30. 

Figure 6.1 O/W nanoemulsion region in the water/polyoxyethylene 4 sorbitan monolaurate/ [10%ethylcellulose (EC10) in ethyl acetate] system at 25 °C. Reproduced with permission from [54].

Rekhi, G.S. and Jambhekar, S.S. (1995) Ethylcellulose - a polymer review. Drug Development and Industrial Pharmacy 21 61-77. 

Lavasanifar, A., Ghalandari, R., Ataei, Z., Zolfaghari, M.E. and Mortazavi, S.A. (1997) Microencapsulation of theophylline using ethylcellulose in vitro drug release and kinetic modelling. Journal of Microencapsulation, 14, 91-100. 

Chen, H Wu, J.-C. and Chen, H.-Y. (1995) Preparation of ethylcellulose microcapsules containing theophylline by using emulsion non-solvent addition method. Journal of Microencapsulation, 12, 137-147. 

Jalsenjak, I., Nicolaidou, C.F. and Nixon, J.R. (1976) The in vitro dissolution of phenobarbitone sodium from ethylcellulose microcapsules. Journal of Pharmacy and Pharmacology, 28, 912-914. 

Benita, S. and Donbrow, M. (1982) Dissolution rate control of the release kinetics of water-soluble compounds from ethylcellulose film-type microcapsules. International Journal of Pharmaceutics, 12, 251-264. 

Tirkkonen, S. and Paronen, P. (1992) Enhancement of drug release from ethylcellulose microcapsules using solid sodium chloride in the wall. International Journal of Pharmaceutics, 88, 39-51. 

Grattard, N., Pernin, M., Marty, B., Roudaut, G., Champion, D. and Le Meste, M. (2002) Study ofrelease kinetics of small and high molecular weight substances dispersed into spray-dried ethylcellulose microspheres. Journal of Controlled Release, 84, 125-135. 

Arias, J.L., Lopez-Viota, M., Lopez-Viota, J. and Delgado, A.V. (2010) Iron/ ethylcellulose (core/shell) nanoplatform loaded with 5-fluorouradl for cancer targeting. Colloids and Surfaces B Biointerfaces, 77, 111—116. 

Spemarth, L. and Magdassi, S. (2007) Preparation of ethylcellulose nanoparticles from nano-emulsion obtained hy inversion at constant temperature. Micro el Nano Letters, 2, 90-95. 

In Fig. 3 the total corrected emission spectrum of MBC in ethylcellulose filmsisshown(curve A)... 

FMC designs one such water-soluble coating for timed-release medications — Aquacoat ECD, a 30% by weight aqueous dispersion of ethylcellulose. This polymer is used to coat drug-layered beads that are delivered using gelatin capsules... 

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