Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Tablets – lozenges – or pills
Reexamination Certificate
2001-04-03
2004-07-20
Spear, James M. (Department: 1615)
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Tablets, lozenges, or pills
C424S464000, C424S474000
Reexamination Certificate
active
06764695
ABSTRACT:
This application is a 371 of PCT/JP99/05463 filed Oct. 05, 1999.
TECHNICAL FIELD
The present invention relates to a tablet and a tablet production method, specifically to a tablet of which active substance (namely medicament) is kept stably without being affected by lubricant in case active substance is colored, decomposed or deteriorated in its potency, when such active substance touches lubricant, and to its production method.
BACKGROUND ART
A tablet is a widely used because it is convenient for carrying and dosing and is easy to be taken for an elder person or a child because it doesn't float on the water when dosing with water.
Lubricant powder other than active substance powder, adjuvant powder and so on is added in molding material (powdered or granular material) to be compressed and tabletted in order to prevent grinding between punches and dies of a molding machine while tabletting and to prevent tabletting problems such as sticking, laminating and capping of produced tablets.
The present inventors have found that some active substances are colored, decomposed or deteriorated in their potencies when such active substances touch lubricant.
In order to avoid such phenomenon, it can be expected to tablet molding material without adding lubricant. However, grinding between punches and dies of a molding and tabletting problems such as sticking, laminating and capping of produced tablets are caused and as a result continuous tabletting can't be executed.
Therefore, under the present situation, lubricant is usually added in molding material giving a preference to industrial production basis even though a tablet is colored or stability of active substance in a tablet is deteriorated.
However, it isn't desirable because colored tablet causes a patient and health personnel such as a doctor and a pharmacist anxiety when such a tablet can be observed from outside like a naked tablet. Further, when potency of active substance in a tablet is deteriorated, objective clinical effect of the tablet may not be adequately brought out.
DISCLOSURE OF INVENTION
The present invention has been proposed to solve the above-mentioned problems. The object of the invention is to provide a tablet in which active substance doesn't touch lubricant and grinding between punches and dies of a molding machine and tabletting problems such as sticking, laminating and capping when producing tablets aren't caused in case active substance included in the tablet is colored, decomposed or deteriorated in its potency when such active substance touches lubricant and to provide a method for producing such a tablet.
According to the tablet of the present invention, it includes active substance affected by lubricant and is comprised of compressed mixture of active substance and adjuvant except for lubricant, and lubricant exists only on the surface of the tablet but isn't included in the tablet.
The term “active substance affected by lubricant” in this specification means active substance which is colored, decomposed or deteriorated in its potency when such active substance touches lubricant.
It is difficult to specify such active substance, however, it includes active substances of which coloring degree of a mixture of active substance, adjuvant except for lubricant, and lubricant after a fixed time is larger than that of a mixture of active substance and adjuvant except for lubricant comparing with that at a start time, or content of active substance in a mixture of active substance, adjuvant except for lubricant, and lubricant after a fixed time is larger than that in a mixture of active substance and adjuvant except for lubricant comparing with that at a start time when coloring degree test (absorbance analysis, color analysis and so on) and stability test are performed respectively.
Further, “active substance affected by lubricant” includes active substance which is affected by moisture in air, proton and so on produced in a tablet, and lubricant.
The term “adjuvant except for lubricant” in this specification is material used for producing a tablet and means material other than lubricant.
More specifically, “adjuvant except for lubricant” may include excipient (filler) for increasing the amount for facilitating handling and for giving required volume as pharmaceutical drugs, binder, disintegrator, and other substance if required, except for lubricant.
“Lubricant” in this specification includes lubricant in narrow sense which is added in molding material for dispersing force applied between powdered particle of molding material at a time of compression (tabletting) and for preventing adhering of powdered material on the punches and dies of a tabletting machine, and also includes glidants which is added in molding material for improving fluidity of molding material.
Such lubricant isn't limited if it is usually used and may include light anhydrous silicic acid, stearic acid, and stearic acid metal salt.
Preferable examples of lubricants are stearic acid metal salt (Mg salt, Ca salt, Al salt, K salt, Na salt) and metal salt such as hydrated aluminum silicate, preferable examples of glidants are metal salt (oxide) such as talc and so on.
The lubricant existing on the surface of the tablet isn't applied on purpose. A part of lubricant applied on the surfaces of the punches and the dies of the tabletting machine used for tabletting is attached on the surface of the tablet at the time of compressing.
As such a tablet doesn't include lubricant therein, the active substance included in the tablet doesn't touch lubricant. Therefore, the active substance isn't colored, decomposed or its potency isn't deteriorated so that the active substance can show high stability.
According to the tablet of the present invention, the active substance affected by lubricant is chemical substance having functional group.
The term “functional group” in this specification includes carboxyl group, amino group, hydroxyl group, ester group, amide group, phosphate group, carbonyl group, sulfonyl group, sulfonyloxy group, guanidyl group, sulfonamide group, halogen (chlorine, fluorosis, iodine, bromine and so on) and so on.
If lubricant is above-mentioned metal salt and active substance having such functional group touches the lubricant, the active substance reacts with metal component (magnesium, calcium and so on) of the lubricant so that it is colored, decomposed or its potency is deteriorated.
However, as the tablet doesn't include lubricant therein, active substance, namely chemical substance having functional group doesn't touch the lubricant. Therefore, the active substance included in the table is stably kept without being colored, decomposed or deteriorating its potency.
According to the tablet in the present invention, the active substance affected by lubricant may be one of ascorbic acid and acetylsalicylic acid.
Ascorbic acid and acetylsalicylic acid are accelerated to be decomposed and colored by stearic acid metal salt (Mg salt, Ca salt), hydrated aluminum silicate, and talc. However, as the tablet doesn't include lubricant therein, ascorbic acid and acetylsalicylic acid included in the tablet doesn't touch the lubricant. Therefore, ascorbic acid and acetylsalicylic acid in the tablet aren't colored, decomposed or their potency isn't deteriorated so that the active substance can be kept stably.
According to the tablet in the present invention, a formulation of the active substance is granule, a formulation of the adjuvant except for lubricant is granule, and the active substance granule and the adjuvant granule are substantially same in particle diameter.
The term “granule” in this specification is a granulated material in which powdered material is grown to be with a fixed particle diameter using binder according to a fluid-bed granulation method.
The phrase “the active substance granule and the adjuvant granule are substantially same in particle diameter” more specifically means that the average particle diameter and the particle size distribu
Iwase Yuji
Morimoto Kiyoshi
Watanabe Yasushi
Fitzpatrick ,Cella, Harper & Scinto
Kyowa Hakko Kogyo Co. Ltd.
Spear James M.
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