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Excipient having high compactability and process for preparing same

  • US 5,574,150 A
  • Filed: 01/03/1994
  • Issued: 11/12/1996
  • Est. Priority Date: 01/05/1993
  • Status: Expired due to Term
First Claim
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1. An excipient having high compactability, comprising white powdery microcrystalline cellulose obtained by subjecting a cellulosic material to hydrolysis with acid or oxidative degradation with alkali, said microcrystalline cellulose having an average degree of polymerization of from 100 to 375 and an acetic acid holding capacity of 280% or more, and having a compression characteristic satisfying an equality of formula (1):

  • ##EQU8## wherein a is from 0.85 to 0.90, b is from 0.05 to 0.10, P represents the compression pressure (kgf/cm2) applied to said microcrystalline cellulose, Vo represents the apparent specific volume (cm3 /g) of said microcrystalline cellulose, and Vp represents the specific volume (cm3 /g) of said microcrystalline cellulose at said compression pressure P,wherein said white powdery microcrystalline cellulose has an apparent specific volume of from 4.0 to 6.0 cm3 /q, a tapping apparent specific volume of 2.4 cm3 /q or more and a specific surface area of less than 20 m2 /g, and a content of particles having a diameter of 355 μ

    m or more of 5% by weight or less, and has an average particle diameter of from 30 to 120 μ

    m, andwherein said white powdery microcrystalline cellulose is further characterized such that when 500 mg of said microcrystalline cellulose is compressed at 100 kqf/cm2 for 10 seconds to form a cylindrical tablet having a circular cross-sectional area of 1 cm2, said tablet has a breaking strength of 10 kqf or more in a diametric direction thereof, and exhibits a disintegration time of 100 seconds or less, andwherein said acetic acid holding capacity means the amount of acetic acid which can be held by the pores of the powdery microcrystalline cellulose when the powdery microcrystalline cellulose is equilibrated with acetic acid, and is expressed in a weight percentage of the acetic acid which can be held by the microcrystalline cellulose, relative to the weight of the microcrystalline cellulose in a dry state, and wherein said tapping apparent specific volume is measured by a method in which a glass cylinder containing the white powdery microcrystalline cellulose lightly packed therein is subjected to tapping onto a stand made of a relatively soft material from a height of several centimeters in an approximately vertical direction until the packing density of the white powdery microcrystalline cellulose is not increased by tapping any more, and the volume of the resultant white powdery microcrystalline cellulose is measured and divided by the weight of the white powdery microcrystalline cellulose.

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