[54]
`
`[76]
`
`aSlOaovyWdCnNY&EeSSae
`
`Inventors: J6rn Moeckel, Am Baechenbuckel
`24/1, D-69118 Heidelberg; Rolf-Dieter
`Gabel, Kurpfalzring 96, D-68723
`Schwetzingen; Heinrich Woog,
`Lindenstrasse 6, D-69514 Laudenbach,
`all of Germany
`
`Appl. No.:
`
`08/793,753
`
`PCTFiled:
`
`Sep. 14, 1995
`
`PCT No.:
`
`PCT/EP95/03610
`
`§ 371 Date:
`
`Mar. 14, 1997
`
`§ 102(e) Date: Mar. 14, 1997
`
`PCT Pub. No.: WO96/08243
`
`PCT Pub. Date: Mar. 21, 1996
`
`Foreign Application Priority Data
`
`Sep. 14,1994
`
`[DE]
`
`Germany ........eee 44 32 757
`
`Tint. C1.o iceecceccecccecsssseeessseeessssecsssneessseeess A61K 9/20
`US. C1. cece 424/464; 424/489; 424/461;
`424/480; 424/451
`Field of Search o....c.cccccccceeeeee 424/464, 482,
`424/466, 480, 489
`
`United States Patent 55
`5,955,106
`[11] Patent Number:
`
`[45] Date of Patent: Sep. 21, 1999
`Moeckelet al.
`
`US005955106A
`
`PHARMACEUTICAL PREPARATION
`CONTAINING METFORMIN AND A
`PROCESS FOR PRODUCINGIT
`
`[56]
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`4,834,985
`5,055,306
`
`5/1989 Elger et al. wesc 424/488
`10/1991 Barry et al. wees 424/482
`
`Primary Examiner—Thurman K. Page
`Assistant Examiner—William E. Benston, Jr.
`
`[57]
`
`ABSTRACT
`
`The present invention concerns pharmaceutical composi-
`tions containing metformin as an active substance and a
`hydrocolloid-forming agent as a retardant and optionally
`standard pharmaceutical auxiliary substances, the residual
`moisture content in the pharmaceutical composition being
`0.5-3% by weight. The invention also concernsa process for
`producing pharmaceutical compositions containing met-
`formin as an active substance and a hydrocolloid-forming
`agent as a retardant and optionally standard pharmaceutical
`auxiliary substances characterized in that the active sub-
`stance and retarding agent or a portion thereof are granulated
`with an aqueous solvent which can optionally contain a
`binder and where appropriate the other portion of the
`retardant or other standard pharmaceutical auxiliaries are
`admixed with the granulate which is then dried until the
`residual moisture content is reduced to 0.5-3% by weight.
`
`19 Claims, No Drawings
`
`AUROBINDO EX1013, 1
`
`AUROBINDO EX1013, 1
`
`

`

`5,955,106
`
`1
`PHARMACEUTICAL PREPARATION
`CONTAINING METFORMIN AND A
`PROCESS FOR PRODUCINGIT
`
`The invention concerns pharmaceutical preparations
`containing metformin hydrochloride (also called metformin
`in the following) as an active substance and a hydrocolloid-
`forming agent as a retardant and a process for their produc-
`tion.
`It is known that metformin hydrochloride is a biguanide
`derivative (1,1-dimethylbiguanide monohydrochloride)
`which has an oral antidiabetic action. Metformin delayed
`release tablets containing 850 mg metformin hydrochloride
`per film tablet (Glucophage® retard) are on the market.
`Since metformin in contrast
`to other active substances
`cannot be pressedin its pure form (the mass disintegrates in
`an unchanged form after
`the compression)
`framework-
`forming auxiliary substances such as polyvinylacetate were
`used in these high-dose delayed release tablets as a retarding
`agent (Lipha, technical information Glucophage® August
`1991, “Bundesverband der Pharmazeutischen Industrie
`e.V.”, publ. Rote Liste 1993, Edition Cantor, Aulendorf
`1993). The mechanism of action of such framework tablets
`is based on the fact that the readily water-soluble metformin
`diffuses out of the tablet independently of pH in the gas-
`trointestinal tract whereas the tablet framework with the
`coating is excreted largely unchanged.
`The disadvantage of using such framework-forming aux-
`iliary substances such as polyvinylacetate is, however, that
`they have to be processed with organic solvents in particular
`during the granulation process, the organic solvent having to
`be removed again as completely as possible before the
`granulate is processed further to compressed pharmaceutical
`forms of administration and for example pressedintotablets.
`The object of the invention was to provide an improved
`pharmaceutical composition for the active substance met-
`formin.
`In particular the form of administration should
`contain the active substance metformin with a highest pos-
`sible content of active substance and a retardant, the retar-
`dant causing a controlled release of the active substance. In
`particular the new pharmaceutical composition should not
`contain framework formers which haveto be processed with
`organic solvents but should be composed on the basis of
`substances that can be processed aqueously. These pharma-
`ceutical compositions should be readily or easily compress-
`ible so that they are suitable for the manufacture of solid
`pharmaceutical forms of administration such as e.g.tablets,
`dragées or comprimatesfor filling into capsules. In the case
`of the manufacture of tablets or other comprimates the
`maximum total weight should be about 1200-1300 mg in
`order not
`to jeopardize the therapeutic safety (patient
`compliance) since larger oral forms of administration are
`often not taken in the prescribed regularity.
`Another object in the processing of the granulate for
`these high-dose forms of administration especially in the
`manufacture of tablets was to solve the problem of capping
`caused by the active substance which is particularly pro-
`nounced in the case of metformin in order to avoid losses of
`
`yield during the production and impairment of the pharma-
`ceutical quality. Capping denotes the detachment of com-
`pressed mass in layers from the manufactured compact
`during the pressing or shortly afterwards (Schepky G. in:
`Bruchhausen, F. von et al.; publ. Hagers Handbuch der
`pharmazeutischen Praxis, Volume 2, Methoden, 5th ed.
`“Springer Verlag”, Berlin 1991). In the case of metformin
`and especially when high doses of active substance are
`present in the granulate it has turned out that the tendency
`for capping is particularly high during the production of
`tablets.
`
`15
`
`20
`
`25
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`2
`The causes for these tabletting problems can be diverse
`and complex. Capping can be caused by an inadequate
`binding agent action, an inadequate or excessive moisture
`content of the granulate, unsuitable crystal forms, strongly
`aerophilic substances, excessive porosity, excessive propor-
`tion of powder, excessive interparticulate binding between
`the granulate particles and by unsuitable granulate forms.
`Machine factors which can lead to capping are an excessive
`pressing force, badly applied or worn tools, excessive press-
`ing rates and poor deaeration of the matrix (fixed pressure).
`However, in the case of the active substance metformin it
`has turned out that the usual measures are not adequate to
`satisfactorily control the capping of the tabletting mass. A
`relatively high proportion of defective tablets was found
`during tablet production and the tabletting had to be discon-
`tinued due to high rejectrates.
`In the present case the object of the invention is achieved
`by providing high-dose pharmaceutical compositions con-
`taining metformin which contain a hydrocolloid-forming
`agent as a retardant and havea residual moisture content in
`the pharmaceutical composition of 0.5-3% by weight. These
`pharmaceutical compositions can be advantageously manu-
`factured using aqueous solvents so that organic solvents are
`no longer required.
`In addition these compositions are
`surprisingly easy to compress. They are therefore particu-
`larly suitable for the manufacture of solid pharmaceutical
`forms of administration such as e.g.
`tablets, dragées or
`capsules and these can be manufactured with the aid of
`standard processing machines on a technical scale and in a
`good quality as well as in a high yield without large losses
`due to the undesired capping. Accordingly a subject matter
`of the invention is also a corresponding process for the
`production of these solid forms of administration in which
`the appropriate pharmaceutical compositions according to
`the invention are used in the form of granulates with a
`residual moisture content of 0.5-3% by weight. The residual
`moisture content is preferably 1-2.5% by weightin particu-
`lar 1.5-2% by weight.
`Surprisingly it was also found that in the case of the
`granulate according to the invention it was possible to omit
`the addition of humectants which are otherwise often nec-
`essary to set a constant residual moisture content until the
`granulate is compressed. This is particularly advantageous
`because it minimizes the addition of auxiliary substances
`and pharmaceutical compositions are obtained with a rela-
`tively high content of active substance. In addition these
`compositions have the advantage that they are stable on
`storage for a period of two days or more (starting from the
`production up to the use of the granulate for tabletting) with
`regard to the moisture content before they are compressed
`without there being a detectable disadvantageous change in
`the composition. This is particularly advantageous since it
`enables several partial batches of production lots of the
`pharmaceutical composition to be produced and these can
`then be mixed as a mass ready to be pressed at a later time
`in a commonlast process step and can be processed to solid
`pharmaceutical forms of administration.
`In addition it surprisingly turned out that the use of a
`hydrocolloid-forming agent enabled for the first time the
`known poor compressibility of metformin to be brought
`under control in a technically satisfactory manner. In addi-
`tion the solution according to the invention enables the
`desired retardation and compressibility to be ensured by the
`selection of the hydrocolloid-forming agent as the retardant
`and with a suitable control of the production process
`(adhering to thecritical residual moisture content of 0.5-3%
`by weightin particular of 1-2.5% by weight and 1.5-2% by
`
`AUROBINDO EX1013, 2
`
`AUROBINDO EX1013, 2
`
`

`

`5,955,106
`
`3
`weight) although the proportion of the hydrocolloid-forming
`agent in the formulation composition is unusually low. This
`is even more surprising since the active substance whose
`water absorbing capacity is very small (the pure active
`substances only binds 0.04% by weight water at a relative
`moisture content of 90%) forms the major proportion of the
`formulation (about 70-95% by weight).
`The proportion by weight of the active substance in the
`high-dose pharmaceutical composition is in the range ofat
`least 70% by weight, preferably 80-95% by weight relative
`to the pharmaceutical composition. The active substance can
`be used in the form of acid addition salts of inorganic or
`organic acids such as e.g. hydrochloric acid, formic acid,
`acetic acid, malic acid, tartaric acid or furmaric acid. The
`hydrochloride salt is preferably used.
`in the
`The proportion of hydrocolloid-forming agent
`pharmaceutical composition is up to 15% by weight pref-
`erably 4-10% by weight and especially about 6-8% by
`weight.
`Within the sense of the invention the standard hydro-
`philic gel forming agents are suitable as hydrocolloid-
`forming agents or as hydrophilic swelling substances such as
`for example cellulose derivatives, dextrins, starch,
`carbohydrate-based polymers, natural or hydrophilic gums,
`xanthanes, alginates, gelatin, polyacrylic acid, polyvinyl
`alcohol or polyvinylpyrrolidone. In the case of the cellulose
`derivatives the alkyl or hydroxyalkyl cellulose derivatives
`preferably come into consideration such as e.g. methyl
`cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose,
`hydroxypropyl cellulose, methylhydroxyethyl cellulose,
`methylhydroxypropyl cellulose or sodium carboxymethyl
`cellulose. In a preferred procedural variant of the invention
`methylhydroxypropyl cellulose (MHPC)
`is used. The
`hydrocolloid-forming agents can be used individually as
`well as in mixtures of two or several colloid-forming agents.
`The standard polymerssuitable for pharmaceutical purposes
`with various degrees of substitution and/or different molecu-
`lar weights corresponding to a different degree of viscosity
`of the aqueous solution can be used as suitable cellulose-
`based polymeric colloid-forming agents.
`The use of hydrocolloid-forming agents as retardants is
`based on the property of the hydrocolloid-forming agents to
`swell and form a gel matrix when they are contacted with a
`release medium or digestive juices which erodesto release
`the active substance. The interaction between the amount of
`
`hydrocolloid-forming agent and the degree of viscosity
`determines the time course of the release. Thus for example
`a high proportion (70-95% relative to the core weight of the
`tablet) of polyvinyl alcohol of a lower or average viscosity
`level can for example retard riboflavin for several hours (M
`ockel J. E., Lippold B. C., Pharm. Research, 1993, 10,
`1066-1070).
`The compressed forms of administration that are pro-
`duced using the pharmaceutical composition according to
`the invention such as for example metformin delayed-
`release tablet cores can be additionally provided with a film
`envelope. The film envelope can on the one hand cause an
`additional retardation by using those film materials which
`represent a film-forming agent whichis usually suitable for
`these purposes. Onthe other handthe film envelope used can
`be a taste-neutralizing film-forming agent to which dyes can
`optionally be added. In addition it is also possible to for
`example use films that are resistant to gastric juice. The
`proportion by weight ofthe film enveloperelative to thefinal
`tablet is in the usual range of 0.3-3.0% by weight preferably
`of 0.8-1.2% by weight. Film formers such as for example
`ethyl cellulose, poly(methylmethacrylate) derivatives
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`4
`(Eudragit®) and also soluble cellulose derivatives such as
`methylhydroxypropyl cellulose and cellulose derivatives for
`forming films resistant to gastric juice such as cellulose
`acetate phthalate or methylhydroxypropyl cellulose phtha-
`late come into consideration as film formers. Ethyl cellulose
`is preferably used. The dissolution of the active substance
`can be delayed by the film that is formed. Softeners, pore
`formers and pigments may bepresentin the film envelope as
`standard auxiliary substances.
`The pharmaceutical composition according to the inven-
`tion can also be used to produce compressed capsule filling
`materials. These comprimates or compacted granulates can
`then be filled into commercial capsules by meansof suitable
`devices. In comparison to the other standard capsule filling
`materials containing metformin these compacted granulates
`have the advantage with the same content of active sub-
`stance and the same dosage that smaller capsules can be used
`due to their smaller volume which can be more easily
`swallowed by the patient.
`The pharmaceutical forms of administration according to
`the invention such as e.g. tablets contain—apart from the
`active substance whose proportion in the form of adminis-
`tration can be in the range of 70-95% by weight (for
`example 850 mg ofthe active substance is preferably used
`in the case of retarded tablets) and the retardant—preferably
`2-10% by weight binder, up to 2% by weight preferably
`0.1-0.3% by weight flow regulating agent and up to 2% by
`weight preferably 0.4-1.1% by weight lubricant each in
`relation to the total weight of the material ready to be
`tabletted or of the tablet core. The weight of a tablet core is
`usually between 200 and 1300 mgpreferably in the range of
`less than 1200 mgespecially of about 500-1000 mg. Flow
`regulating agents which come into consideration for the
`tablet according to the invention are standard agents such as
`for example colloidal silicon dioxide. Talcum or stearic acid
`or alkali or alkaline earth salts thereof in particular magne-
`sium stearate are for example suitable as lubricants.
`Examples of binding agents that can be used are cellulose
`derivatives especially alkyl and hydroxyalkyl celluloses in
`particular methyl cellulose, hydroxymethyl cellulose,
`hydroxyethyl cellulose, hydroxypropyl cellulose, methylhy-
`droxyethyl cellulose, methylhydroxypropyl cellulose,
`sodium carboxymethyl cellulose etc., dextrins, starches,
`especially soluble starches, other polymers based on carbo-
`hydrates such as e.g. galactomannans, natural gums such as
`gum arabic, Traganth, Sterculia, Acacia and others,
`xanthane, alginates, polyacrylic acid, polyvinyl alcohol and
`polyvinylpyrrolidone. Polyvinylpyrrolidone is preferably
`used.
`
`The pharmaceutical forms of administration according to
`the invention such as e.g. tablets are produced by dry mixing
`the active substance,
`the retardant or a portion of the
`retardant and optionally further auxiliary substances, wet-
`granulating with water or an aqueous solution of a binder,
`drying the material ready for tabletting to a desired residual
`moisture content and subsequently where appropriate the
`remaining portion of the retardant or other pharmaceutical
`auxiliary substances are admixed with the granulate so that
`in the last process step a residual moisture content of 0.5-3%
`by weight is achieved in the pharmaceutical composition.
`The determination of the residual moisture contentis carried
`
`out by known analytical methods of aquametry for example
`by determining the water content with the aid of the Karl-
`Fischer reagent or other alternative methods of determina-
`tion. In the wet granulation a portion of the active substance,
`the auxiliary substances used as well as the retardant may
`also be present dissolved or suspended completely or par-
`
`AUROBINDO EX1013, 3
`
`AUROBINDO EX1013, 3
`
`

`

`5,955,106
`
`5
`tially in water. Optionally it is also possible to add organic
`solvents that are miscible with water such as for example
`acetone or lower alcohols such as methanolor ethanol.
`
`It is expedient to adjust the residual moisture content
`while drying in a fluid bed process in which the moist
`granulate is dried until the measured moisture content in the
`outlet air has reached the value previously determined when
`the residual moisture content in the drying material was
`calibrated. The composition produced in this manner is
`subsequently processed in the usual manner to form phar-
`maceutical forms of administration and for example pressed
`into tablets. The tablets can be coated with a film using the
`standard coating processes. It was found that the residual
`moisture content of 0.5-3% by weight that was set with the
`aid of the hydrocolloid-forming agent ensures that
`the
`material ready for tabletting can be compressed over the
`entire range of pressing force required to produce large
`tablets without capping.
`The active substance can be processed completely or
`partially with the hydrocolloid-forming agent used for the
`retardation to form a granulate or the hydrocolloid-forming
`agent
`is mixed completely with a granulate free of
`hydrocolloid-forming agent after its production. However,
`an additional improvementin the tablet-forming properties
`is achieved when the hydrocolloid-forming agent or a por-
`tion thereof is granulated with the active substance.
`The tablet is coated by standard methodssuchase.g. the
`coating pan or fluid bed process.
`The retarded tablets according to the invention release
`metformin in a controlled manner over a time period of
`0.5-10 hours preferably over 4 hours (FIG. 1). Since due to
`the use of a hydrocolloid-forming agent large amounts of
`additional auxiliary substances and in particular no humec-
`tants such as for example glycerol or sorbitol are necessary,
`the maximum weight of the tablets is 1200 mg preferably
`below 1000 mg.
`It is intended to elucidate the invention in the following
`by the procedural examples without limiting it thereto.
`In the following examples 1-6 the residual moisture
`content was adjusted to the range according to the invention
`before the pharmaceutical composition in the form of a mass
`ready for pressing was pressed into tablets. In examples 7
`and 8 the residual moisture content wasset to a value of less
`
`than 0.5% by weight. In these two cases the tabletting had
`to be terminated due to high losses caused by capping.
`
`EXAMPLE1
`
`Hydrocolloid-forming agent: methylhydroxypropyl cellu-
`lose (MHPC). The MHPCcontent can be varied e.g. from
`40-95 mg.
`residual moisture: 2.1%
`
`Constituents
`Core:
`
`metformin hydrochloride
`methylhydroxypropyl
`cellulose
`polyvidone
`magnesium stearate
`core total:
`
`Tablet
`[mg]
`
`850.00
`60.00
`
`38.00
`5.00
`953.00
`
`Massready for
`pressing
`[kg/1 mio. pieces]
`
`850.00
`60.00
`
`38.00
`5.00
`953.00
`
`10
`
`20
`
`25
`
`30
`
`35
`
`40
`
`50
`
`55
`
`60
`
`6
`-continued
`
`Tablet
`[mg]
`
`20.00
`
`12.00
`4.00
`4.00
`
`40.00
`993.00
`
`Massready for
`pressing
`[kg/1 mio. pieces]
`
`20.00
`
`12.00
`4.00
`4.00
`
`40.00
`993.00
`
`Constituents
`
`Film envelope:
`
`methylhydroxypropyl
`cellulose
`ethyl cellulose
`Macrogol
`titanium dioxide
`
`envelope total:
`film tablet total:
`
`Production
`
`The production of granulate for an amount of about 1
`million tablets is carried out in five partial batches. For each
`of the five partial batches 170 kg metformin hydrochloride
`and 12 kg methylhydroxypropyl] cellulose were dry mixed
`together and wet-granulated in a mixer with a 10% aqueous
`binder solution of polyvidone. Subsequently the granulate is
`dried in a fluid bed granulator until
`it has an adequate
`residual moisture content. The five partial batches are com-
`bined and admixed with 5 kg magnesium stearate. The mass
`ready for pressing is tabletted. The tablet cores are coated in
`a coating pan with the film of the described composition.
`In the stated formulation the residual moisture content is
`adjusted to 2.1%. The tabletting proceeds correspondingly
`without problems i.e. a capping of the manufactured tablet
`mass cannot be detected.
`
`EXAMPLE 2
`
`Hydrocolloid-forming agent: hydroxyethyl cellulose
`
`Residual moisture: 2.0%
`
`Constituents
`Core:
`
`metformin hydrochloride
`hydroxyethyl cellulose
`polyvidone
`magnesium stearate
`core total:
`Film envelope:
`
`methylhydroxypropyl
`cellulose
`lactose
`ethyl cellulose
`Macrogol
`titanium dioxide
`
`envelope total:
`film tablet total:
`
`Tablet
`[mg]
`
`850.00
`70.00
`40.00
`5.00
`965.00
`
`5.00
`5.00
`10.00
`3.00
`3.00
`
`26.00
`991.00
`
`Massready for
`pressing
`[kg/1 mio. pieces]
`
`850.00
`70.00
`40.00
`5.00
`965.00
`
`5.00
`5.00
`10.00
`3.00
`3.00
`
`26.00
`991.00
`
`The granulate is produced and processed analogously to
`example 1; the tabletting proceeds correspondingly without
`problems.
`
`AUROBINDO EX1013, 4
`
`AUROBINDO EX1013, 4
`
`

`

`7
`EXAMPLE3
`
`8
`EXAMPLE 5
`
`5,955,106
`
`Hydrocolloid-forming agent: sodium carboxymethyl cel-
`lulose
`
`Residual moisture: 2.1%
`
`Constituents
`Core:
`
`metformin hydrochloride
`sodium carboxy methyl
`cellulose
`polyvidone
`magnesium stearate
`core total:
`Film envelope:
`
`methylhydroxypropyl
`cellulose
`ethyl cellulose
`Macrogol
`titanium dioxide
`
`envelope total:
`film tablet total:
`
`Tablet
`[mg]
`
`850.00
`80.00
`
`35.00
`5.00
`970.00
`
`5.00
`
`10.00
`4.00
`3.00
`
`22.00
`992.00
`
`Massready for
`pressing
`[kg/1 mio. pieces]
`
`850.00
`80.00
`
`35.00
`5.00
`970.00
`
`5.00
`
`10.00
`4.00
`3.00
`
`22.00
`992.00
`
`The granulate is produced and processed analogously to
`example 1; the tabletting proceeds correspondingly without
`problems.
`
`EXAMPLE4
`
`Hydrocolloid-forming agent: polyacrylic acid
`
`Residual moisture: 2.8%
`
`Constituents
`Core:
`
`metformin hydrochloride
`polyacrylic acid
`methylhydroxypropyl
`cellulose
`magnesium stearate
`core total:
`Film envelope:
`
`methylhydroxypropyl
`cellulose
`ethyl cellulose
`Macrogol
`titanium dioxide
`
`Tablet
`[mg]
`
`850.00
`60.00
`30.00
`
`5.00
`945.00
`
`10.00
`
`10.00
`3.00
`3.00
`
`Massready for
`pressing
`[kg/1 mio. pieces]
`
`850.00
`60.00
`30.00
`
`5.00
`945.00
`
`10.00
`
`10.00
`3.00
`3.00
`
`Hydrocolloid-forming agent: hydroxypropyl cellulose
`Residual moisture: 1.95%
`
`Constituents
`Core:
`
`metformin hydrochloride
`hydroxypropyl cellulose
`polyvidone
`magnesium stearate
`core total:
`Film envelope:
`
`poly(ethylacrylate-methyl
`methacrylate) dispersion 30%
`talcum
`anti-foaming agent
`
`envelope total:
`film tablet total:
`
`Tablet
`[mg]
`
`850.00
`60.00
`40.00
`5.00
`955.00
`
`6.00*
`1.20
`0.07
`
`7.27
`962.270
`
`Mass ready for
`pressing
`[kg/1 mio. pieces]
`
`850.00
`60.00
`40.00
`
`5.00
`955.00
`
`6.00*
`1.20
`
`0.07
`
`7.27
`962.270
`
`*Stated quantity refers to the dry substance.
`
`The granulate is produced and processed analogously to
`example 1. As a variant the hydrocolloid-forming agent
`hydroxypropylcellulose is in this case not granulated simul-
`taneously but admixed dry with the completed granulate.
`
`EXAMPLE6
`
`Hydrocolloid-forming agent: methylhydroxypropy] cellu-
`lose
`Residual moisture: 2.0%
`In the following example an additional binder is com-
`pletely omitted,
`the methylhydroxypropyl cellulose used
`adopts the function of both binder and retardant.
`
`Tablet
`[mg]
`
`850.00
`100.00
`
`5.00
`955.00
`
`20.00
`
`12.00
`4.00
`4.00
`
`40.00
`995.00
`
`Massready for
`pressing
`[kg/1 mio. pieces]
`
`850.00
`100.00
`
`5.00
`955.00
`
`20.00
`
`12.00
`4.00
`4.00
`
`40.00
`995.00
`
`Constituents
`Core:
`
`metformin hydrochloride
`methylhydroxypropyl
`cellulose
`magnesium stearate
`core total:
`Film envelope:
`
`methylhydroxypropyl
`cellulose
`ethyl cellulose
`Macrogol
`titanium dioxide
`
`envelope total:
`film tablet total:
`
`Production
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`50
`
`55
`
`26.00
`26.00
`envelope total:
`
`
`971.00film tablet total: 971.00
`
`The granulate is produced and processed analogously to
`example 1. As a variant methylhydroxypropyl cellulose in
`this case serves as a binder. The tabletting proceeds corre-
`spondingly without problems.
`
`65
`
`The production of granulate is carried out in five partial
`batches. For each of the five partial batches 170 kg met-
`formin hydrochloride and 18 kg methylhydroxypropyl cel-
`lulose are placed in a fluid bed granulator. 2 kg methylhy-
`droxypropyl cellulose is dissolved in 50 1 water. The dry
`mixture is granulated with the binder solution in a fluid bed
`granulator and subsequently dried. The five partial batches
`are combined and admixed with 5 kg magnesium stearate.
`
`AUROBINDO EX1013, 5
`
`AUROBINDO EX1013, 5
`
`

`

`5,955,106
`
`9
`The massreadyfor pressing is tabletted. The tablet cores are
`coated in a coating pan with the film of the described
`composition.
`
`EXAMPLE 7
`
`Hydrocolloid-forming agent: methylhydroxypropyl cellu-
`lose
`Residual moisture: 0.49%
`A moisture content of 0.49% was obtained with the
`mixture below. The tabletting had to be stopped due to high
`losses by capping.
`
`Constituents
`Core:
`
`metformin hydrochloride
`methylhydroxypropyl cellulose
`polyvidone
`magnesium stearate
`core total:
`film envelope:
`
`methylhydroxypropyl cellulose
`ethyl cellulose
`Macrogol
`titanium dioxide
`
`envelope total:
`film tablet total:
`
`Tablet
`[mg]
`
`850.00
`40.00
`38.00
`
`5.00
`953.00
`
`20.00
`12.00
`4.00
`
`4.00
`
`40.00
`993.00
`
`EXAMPLE8
`
`Hydrocolloid-forming agent: gelatin
`Residual moisture: 0.48%
`A moisture of 0.48% was obtained with the mixture
`below. The tabletting had to be stopped due to high losses by
`capping.
`
`Constituents
`Core:
`
`metformin hydrochloride
`lactose
`gelatin
`silicon dioxide, highly dispersed
`magnesium stearate
`core total:
`film envelope:
`
`methylhydroxypropyl cellulose
`ethyl cellulose
`diethyl phthalate
`titanium dioxide
`
`envelope total:
`film tablet total:
`
`Weclaim:
`
`[mg]
`
`850.00
`70.00
`40.00
`2.00
`
`2.50
`964.50
`
`10.00
`9.00
`3.00
`
`3.00
`
`25.00
`989.5
`
`1. Pharmaceutical composition comprising metformin as
`the active substance and a hydrocolloid forming retarding
`agent, wherein the pharmaceutical composition has a
`residual moisture content of about 0.5-3% by weight.
`
`least 70% by
`
`10
`2. Composition of claim 1, wherein at
`weight of the composition is metformin.
`3. Composition of claim 1, wherein about 4-15% by
`weight of the composition is the hydrocolloid forming
`retarding agent.
`4. Composition of claim 1, wherein the retarding agent is
`selected from the group consisting of cellulose derivatives,
`dextrins, starches, carbohydrate polymers, natural gums,
`xanthane, alginates, gelatin, polyacrylic acid, polyvinyl
`alcohol and polyvinyl pyrrolidone.
`5. Composition of claim 4, wherein the retarding agent is
`a cellulose derivative.
`
`6. Composition of claim 5, wherein the cellulose deriva-
`tive is an alkyl or hydroxyalkyl cellulose.
`7. Composition of claim 6, wherein the cellulose deriva-
`tive is selected from the group consisting of methyl
`cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose,
`hydroxypropyl cellulose, methylhydroxyethyl cellulose,
`methylhydroxypropyl cellulose or sodium carboxymethyl
`cellulose.
`
`8. Composition of claim 1, further comprising about
`3-5% by weight of binder, up to 2% by weight of flow
`regulating agent and up to 2% by weight of lubricant.
`9. Composition of claim 1 in the form of a tablet or
`capsule.
`10. Pharmaceutical tablets or compacted product for fill-
`ing into capsules comprising metformin as the active sub-
`stance and a hydrocolloid-forming retarding agent, the tab-
`lets having cores, wherein the cores or compacted product
`have a residual moisture content of about 0.5-3% by weight.
`11. Product of claim 10, wherein the productis a tablet
`having a weight less than 1300 mg.
`12. Process for producing a retarded metformin pharma-
`ceutical composition which can be compressed, comprising
`
`granulating metformin and a hydrocolloid-formingretard-
`ing agent with an aqueoussolvent to form a granulated
`product,
`and drying the granulated product to a residual moisture
`content of about 0.5 to 3% by weight.
`13. Process of claim 12, including the further step of
`admixing further retarding agent with the granulated product
`prior to the drying step.
`14. Process of claim 12, wherein the aqueoussolvent used
`in the granulation step contains a binder.
`15. Process of claim 12, including the further step of
`compressing the dried granulated product into tablets.
`16. Process of claim 15, including the further step of
`coating the tablets with a film envelope.
`17. Process of claim 12, including the further steps of
`compacting the dried granulated product to form a com-
`pacted product, and filling the compacted product
`into
`capsules.
`18. Process of claim 12, wherein the retarding agent is
`methylhydroxypropyl] cellulose.
`19. Process of claim 12, wherein the compacted product
`further includes up to 2% by weightof lubricant, up to 2%
`by weight of flow regulating agent and up to 5% by weight
`of binder.
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`AUROBINDO EX1013, 6
`
`AUROBINDO EX1013, 6
`
`