2-Hydroxypropyl methylcellulose phthalate

Some extended-release preparations are designed with a coating that responds to the acidity of its environment. The polymeric coating of the medicine is formulated for stability during oral delivery and for eventual solubility at the intended organ. The contrasting acidic content of the stomach and the more basic environment of the intestines enable these formulations to function. For example, hydroxypropyl methylcellulose phthalate (HPMCP) (Fig. 14.1.3) is an enteric... 

Figure 14.1.3 The repeating unit of the polymer hydroxypropyl methylcellulose phthalate (HPMCP).

Duloxetine hydrochloride, a novel anti-depressive, is known to be acid labile and, consequently, it has been formulated as an enteric-coated tablet. Interestingly, Jansen et al. [97] subsequently found that the drug was destabilised by degradation products within these enteric polymers. The authors found that succinyl and phthalyl residues from the hydroxypropyl methylcellulose acetate succinate (HPMCAS) and hydroxypropyl methylcellulose phthalate (HPMCP) formed... 

Hydroxypropyl methylcellulose phthalate (HPMCP) dissolves at pH greater than 5 and has two major grades, HP-55 and HP-55S. HPMCP shares the same problem as CAP and needs shellac to prevent permeation of water vapor and gastric fluids. 

A radiotelemetric method has been described to test the disintegration property of a tablet [58], A tablet containing a citrate buffer was coated with hydroxypropyl methylcellulose phthalate and then placed in a Heidelberg capsule that also contained a pH-electrode (Figure 8). An antenna is strapped around the midriff of the dog to detect the output from the Heidelberg capsule. 

Water-soluble hydroxypropylmethyl cellulose and water-insoluble cellulose acetate are further treated with phthalic anhydride or succinic anhydride to yield hydroxypropyl methylcellulose phthalate, cellulose acetate phthalate, and hydroxypropyl-methylcellulose acetate succinate. These polymers are used as enteric materials and are water soluble or insoluble above or below a specific pH, respectively. 

Kim, I. H., Park, J. H., Cheong, I. W., and Kim, J. H. (2003), Swelling and drag release behavior of tablets coated with aqueous hydroxypropyl methylcellulose phthalate (HPMCP) nanoparticles, /. Controlled Release, 89,225-233. 

Kitagawa H, Satoh T, Yokoshima T, Nanbo T. Absorption, distribution and excretion of hydroxypropyl methylcellulose phthalate in the rat. Pharmacometrics 1971 5 1. ... 

Cellulose phthalate hydroxypropyl methyl ether HPMCP hydroxypropyl methylcellulose benzene-1,2-dicar boxy late 2-hydroxypropyl methylcellulose phthalate methylhydroxypro-pylcellulose phthalate. 

Muhammad NA, Boisvert W, Harris MR, Weiss J. Evaluation of hydroxypropyl methylcellulose phthalate 50 as film forming polymer from aqueous dispersion systems. Drug Dev Ind Pharm 1992 18 1787-1797. 

Sertsou G, Butler J, Hempenstall J, Rades T. Solvent change coprecipitation with hydroxypropyl methylcellulose phthalate to improve dissolution characteristics of a poorly water-soluble drug. ] Pharm Pharmacol 2002 54(8) 1041-1047. 

Shin-Etsu Chemical Co. Ltd. Technical literature Hydroxypropyl methylcellulose phthalate, 1993. 

Kitagawa H, Kawana H, Satoh T, Fukuda Y. Acute and subacute toxicities of hydroxypropyl methylcellulose phthalate. Pharmaco-metrics 1970 4(6) 1017-1025. 

Ito R, Toida S. Studies on the teratogenicity of a new enteric coating material, hydroxypropyl methylcellulose phthalate (HPMCP) in rats and mice. Med Soc Toho-XJniv 1972 19(5) 453 61. 

Kitagawa H, Yokoshima T, Nanbo T, Hasegawa M. Absorption, distribution, excretion and metabolism of " C-hydroxypropyl methylcellulose phthalate. Pharmacometrics 1974 8(8) 1123-1132. 

In 1940, Eastman Kodak Company published a U.S. patent that provided one of the earliest de.scriptions of enteric coating of medicaments. The patent claimed the use of a cellulose derivative containing free carboxyl groups as an enteric film forming polymer. Specifically, the claimed enteric polymer was cellulose acetate phthalate (CAP) (34). Numerous enteric cellulose derivatives have been developed since this early account and these polymers remain as some of the most widely used for enteric coating applications. In addition to CAP these derivatives include cellulose acetate trimellitate (CAT), cellulose acetate succinate (CAS), hydroxypropyl methylcellulose phthalate (HPMCP), and hydroxypropyl methylcellulose acetate succinate (HPMCAS). The molecular structure of these polymers is depicted in Figure 1 with their respective substituent groups listed in the caption. 

Hydroxypropyl methylcellulose phthalate CHPMCP1 Above pH 4.5 Optimal dissolution profile for enteric coating. 

Hydroxypropyl methylcellulose phthalate Polyvinylpyrrolidone-co-vinyl acetate Hydroxypropyl methylcellulose Hydroxypropyl methylcellulose acetate succinate Poly(lactide-co-glycolide)... 

Hydroxypropyl methylcellulose phthalate (HPMCP) Poly(methacrylic acid-co-methyl methacrylate) Poly(vinyl acetate phthalate) (PVAP)... 

See Hydroxypropyl methylcellulose phthalate HPO-9036 HPO-9050 HPO-907O See Phosphoric acid... 

Hydroxypropyl methylcellulose phthalate Synonyms HPMCP Hypromellose phthalate Definition A monophthalic acid ester of hydroxypropyl methylcellulose Properties Wh. powd., odorless, tasteless pract. insol. in water... 

Cellulose acetate phthalate film-former, enteric pharmaceuticals Hydroxypropyl methylcellulose phthalate film-former, explosives Dibutyl phthalate film-former, fixing lotions PVP/VA/vinyl propionate copolymer VA/crotonates/vinyl propionate copolymer film-former, flexible hoses Ethylene/methyl acrylate copolymer film-former, floor finishes Ethylene/acrylic acid/vinyl acetate copolymer film-former, flooring compounds Acrylamides copolymer film-former, food... 

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