Cellulose coating

With regard to the resolution of enantiomers, some applications can be found with modified silica gel supports. Thus, a Pirkle-type CSP was used for the separation of 200 mg of a racemic benzodiazepinone [75]. Also tris-(3,5-dimethylphenyl)carba-mate of cellulose coated on silica [91, 92] was applied successfully to the resolution of the enantiomers of 2-phenoxypropionic acid and to oxprenolol, alprenolol, propranolol among other basic drugs. However, the low efficiency of this technique and the relative high price of the CSPs limits its use to the resolution of milligram range of sample. 

The synthesis of vinylsulfonyl dyes is a good example for a method to obtain pH indicator layers with operational stability of weeks and shelf life of years. Commercial transparencies with a cellulose coating are used as the polymer matrix and the reactive vinylsulfonyl dye is bound to the cellulose... 

Perkins AC, Wilson CG, Frier M, Vincent RM, Blackshaw PE, Danserau RJ, Juhlin KD, Bekker PJ, Spiller RC. Esophageal transit of risedronate cellulose-coated tablet and gelatin capsule formulations. Int J Pharm 1999 186 169-175. 

Francotte, E., and Jung, M. (1996). Enantiomer separation by open-tubular EC and electrochromatography in cellulose-coated capillaries. Chromatographia 42, 521—527. 

Uses Solvent for nitrocellulose and ethyl cellulose coated paper, lacquers cements nail enamels, leather finishes textile sizing and printing compounds plastic wood. 

As mentioned before, nifedipine was the first marketed dihydropyridine CCB. Initially, the drug indication was exclusively for angina, but the more recently developed extended release (ER) formulations are used off-label primarily for hypertension (Bayer, 2004). The extended-release tablets use a cellulose coat that extends their release time. The half-life of the ER formulation is reported as 7 h, whereas the immediate-release formulation has a half-life of 2 h (Bayer). 

The enzyme-activated cellulose technology is an ex situ process that was designed to treat contaminated water. Cellulose, coated with a proprietary enzyme, is used to remove metals and organic compounds from an aqueous solution. 

Ethyl cellulose Coating agent Starch (corn, wheat, potato, rice) Tablet filler... 

Hydroxyethyl cellulose Coating agent Talc Glidant... 

Hydroxypropyl cellulose Coating agent Triacetin Solvent... 

A rapid electrophoretic method for the simultaneous separation and estimation of vitamin Bg and derivatives from various tissues has been described (105). The method is based on high voltage electrophoresis of small aliquots of tissue extracts, applied on cellulose-coated plates. The method is sensitive upto 1 yg of vitamin Bg. 

Columns of dextran have been prepared with a more elaborate procedure.13 It is claimed that the EOF has been eliminated and that columns are very stable under very harsh conditions, e.g., 0.05 M NaOH with 5% SDS or 1 M HC1. Cellulose-coated capillaries have been prepared by coupling 2-hydroxyethyl methacrylate (HEMA)-derivatized hydroxypropyl cellulose (HPC) to columns derivatized with 7-oct-l-enyltrimethoxysilane.The coating was stable for several weeks in the pH range from 2 to 10 and diminished the EOF, and it has been found useful for separation of peptides, glycoproteins, and derivatized oligosaccharides. 

Polyethylene glycol treatment — Ethyl cellulose coating... 

Li, S.P. Mehta, G.N. Buehler, J.D. Grim, W.M. Harwood, R.J. The effect of film-coating additives on the in vitro dissolution release rate of ethyl cellulose-coated theophylline granules. Pharm. Tech. 1990, 14 (Mar), 20-24. 

Dressman JB, Derbin GM, Ismailos G, et al. Gircumvention of pH-dependent release from ethyl cellulose-coated pellets. / Control Release 1995 36(3) 251-260. 

Iyer U, Hong WH, Das N, Ghebre-Sellassie I. Gomparative evaluation of three organic solvent and dispersion-based ethyl cellulose coating formulations. Pharm Technol 1990 14(9) 68—... 

Solvent Systems Suitable for the Separation op Amino Acid Mixtures on Cellulose-Coated Thin-Layer Chromatographic Plates"... 

Fig. 2 (adapted from [23]). Scanning electron micrographs of (a) cellulose-coated commercial AC used in Adsorba 300C haemoperfusion column (Gambro, Sweden) and (b) unooated AC produced from phenol-formaldehyde resin (MAST Carbon Ltd., Guildford, Surrey, UK). 

Plant Residues. The paraquat residues in Cannabis plants at differ-ent times after application and the percent of i C extract with ethyl acetate and methanol are shown in Table I. Combustion of plant material harvested at 29 h showed a significant loss of C (69%) when compared to time 0. The amount of C extracted with methanol also exhibited a decline with time, particularly at 29 h. Vincent et al. (8) have also observed a similar loss of paraquat residues on the same collection of Cannabis, using a residue method based on sodium dithioate reduction of the extracted paraquat, followed by spectrophotometric analysis. Attempts to examine the possible production of labeled products by thin-layer chromatography on cellulose-coated plates with several solvent systems have been unsuccessful to date due to the high ratio of plant material to labeled paraquat in the samples. The plant residues measured in the present study would appear to be consistent with mean values (331 ppm) found in 20 confiscated marihuana samples reported by Turner et al. (9), although there was considerable variation (2-2264 ppm) in the confiscated samples. 

Influence of Oxide Additives on the Relative Adhesion Properties of the Ethyl Cellulose Coatings to a Steel Plate ... 

Uses Solvent for manufacturing processes, prod, of printing inks latent solvent in cellulosic coatings... 

---