in describing and claiming the present invention , the following terminology is used in accordance with the definitions set out herein . as used herein , the term “ active ingredient ”, “ drug ” or “ pharmacologically active ingredient ” or any other similar term means any chemical or biological material or compound suitable for administration by the methods previously known in the art and / or by the methods taught in the present invention , that induces a desired biological or pharmacological effect , which may include but is not limited to ( 1 ) having a prophylactic effect on the organism and preventing an undesired biological effect such as preventing an infection , ( 2 ) alleviating a condition caused by a disease , for example , alleviating pain or inflammation caused as a result of disease , and / or ( 3 ) either alleviating , reducing , or completely eliminating the disease from the organism . the effect may be local , such as providing for a local anaesthetic effect , or it may be systemic . as used herein , the term “ controlled release delivery ” or “ controlled release ” means that the release of the active ingredient out of the dosage form is controlled with respect to time or with respect to the site of delivery . the term “ coat ” is used herein to encompass coatings for solid supports and also capsules enclosing fluids and / or solids and the term “ coated ” is used similarly . the expression “ water insoluble polymer ” should be understood broadly , this expression refers to polymers that do not completely dissolve in water , such as for example ethyl cellulose , certain starch derivatives or acrylic acid / methacrylic acid derivatives . the term “ indigestible polysaccharide ” as used in the present invention refers to saccharides which are not or only partially digested in the intestine by the action of acids or digestive enzymes present in the human upper digestive tract ( small intestine and stomach ) but which are at least partially fermented by the human intestinal flora . indigestible polysaccharide that may be employed in preferred embodiments of the invention are polysaccharides containing indigestible glucosidic linkages conferring on those saccharides additional properties identical to dietetic fibers such as “ branched polysaccharides ”. in the sense of the invention , by branched maltodextrins or dextrins is meant maltodextrins or dextrins , of which the content of glucosidic linkages 1 → 6 is greater than that of standard maltodextrins or dextrins . for example , standard maltodextrins are defined as purified and concentrated mixtures of glucose and glucose polymers essentially linked in 1 → 4 with only 4 to 5 % glucosidic linkages 1 → 6 , of extremely varied molecular weights , completely soluble in water and with low reducing power . examples of those indigestible polysaccharides are polydextrose , branched dextrins or branched maltodextrins such as those described in patent ep 1 006 128 , of which the applicant company is the proprietor . in practice , the number average molecular mass ( mn ) and the weight average molecular mass ( mw ) values which allow a better definition of the polymolecular species of the polymer mixtures , are measured by gel permeation chromatography , on chromatography columns calibrated with dextrans of known molecular weight ( alsop et al ., process biochem , 12 , 15 - 22 ; 1977 or alsop et al ., chromatography 246 , 227 - 240 ; 1982 ). this method of measurement is very suitable for glucose polymers and is the method used within the context of the present invention . the index of polymolecularity ( i . p .) that is the ratio mw / mn makes it possible to characterize overall the distribution of the molecular weights of a polymer mixture . the indigestible polysaccharide according to the present invention have a total fiber content of greater than or equal to 50 % on a dry basis , determined according to aoac method no . 2001 - 03 ( 2001 ). the invention provides novel polymeric film coatings for colon targeting which are adapted to the disease state of the patients suffering from inflammatory bowel diseases . in the following , the invention will be illustrated by means of the following examples as well as the figures . aminosalicylic acid ( 5 - asa ; falk pharma , freiburg , germany ); glyceryl behenate ( compritol ® 888 ato ) and glyceryl palmitostearate ( precirol ® ato 5 ) ( gattefosse ®, st . priest , france ); hydrogenated soybean oil ( sterotex ® hm ) and hydrogenated cottonseed oil ( sterotex ® nf ) ( abitec , janesville , wis ., usa ); glyceryl trimyristate / glyceryl tripalmitate / glyceryl tristearate / hardened soybean oil ( dynasan ® 114 / 116 / 118 / 120 ) and synthetic hard paraffines ( sasolwax ® spray 30 and synthetic wax ) ( sasol , witten , germany ); ips ( nutriose ® fb 06 ; roquette freres , lestrem , france ); microcristalline cellulose ( mcc , avicel ph 101 ; fmc biopolymer , brussels , belgium ); poly ( vinylpyrrolidone ) ( pvp , povidone ® k30 ) ( cooperation pharmaceutique francaise , melun , france ); chitosan ( protasan ® c1 213 ; novamatrix ®, fmc biopolymer , drammen , norway ); microwax ® hg and microwax ® hw ( paramelt , heerhugowaard , the netherlands ); pancreatin ( from mammalian pancreas = mixture of amylase , protease and lipase ) and pepsin ( fisher bioblock , illkirch , france ). 5 - asa loaded matrix pellets were prepared by extrusion - spheronisation . the drug , ips and the respective lipid ( s ) were blended and granulated manually with demineralized water in a mortar with a pestle . the obtained wet mass was extruded using a cylinder extruder with two counter - rotating rollers ( 1 mm orifice , 3 mm thickness , extrusion speed = 32 rpm , ga 65 extruder ; alexanderwerk , remscheid , germany ). the extrudates were subsequently spheronised ( caleva model 15 ; caleva , dorset , uk ) for 180 s at 364 rpm . the obtained pellets were dried for 24 h in an oven at 40 ° c . and sieved ( fraction : 0 . 71 - 1 . 00 mm ). if indicated , the pellets were cured for specific time periods at defined temperatures in an oven . 5 - asa , ips and the respective lipid ( s ) were blended manually in a mortar with a pestle . mini tablets were prepared by : ( i ) direct compression on a frank 81802 ( karl frank , birkenau , germany ), equipped with a 2 mm diameter punch set ( korsch , berlin , germany ), or ( ii ) compression of granules obtained via melt granulation . if not otherwise stated , the respective compounds were heated and mixed on a water bath at 85 ° c . after cooling to room temperature , the obtained mass was ball milled , sieved ( fraction 50 - 100 μm ) and compressed using the same equipment as in ( i ). the tablet height was 2 mm . optionally , the tablets were cured in an oven for different time periods at various temperatures , as indicated . drug release from matrix pellets was measured in 120 ml cylindrical plastic flasks ( diameter : 5 . 5 cm , height : 6 . 5 cm ) containing 100 ml release medium : 0 . 1 n hcl ( optionally containing 0 . 32 % w / v pepsin ) for 2 h and phosphate buffer ph 6 . 8 ( usp 32 ) ( optionally containing 1 . 0 % w / v pancreatin ) for 8 h ( complete medium change after 2 h ). the flasks were agitated in a horizontal shaker ( 37 ° c ., 80 rpm , n = 3 ) ( gfl 3033 ; gesellschaft fuer labortechnik , burgwedel , germany ). at pre - determined time points , 3 ml samples were withdrawn ( replaced with fresh medium ), filtered and analyzed uv - spectrophotometrically at λ = 302 . 4 nm ( 0 . 1 n hcl ), or λ = 331 . 2 nm ( phosphate buffer ph 6 . 8 ) ( uv - 1650pc ; shimadzu , champs - sur - marne , france ). in the presence of enzymes , the samples were centrifuged at 13 , 000 rpm for 10 min ( universal 320 centrifuge ; hettich , tuttlingen , germany ) and filtered ( 0 . 2 μm , ptfe ) prior to uv measurements . drug release from mini tablets was measured using the usp 32 apparatus 3 ( bio dis ; varian , les ulis , france ) ( 37 ° c ., 5 dpm , n = 3 ) in 200 ml release medium : 0 . 1 n hcl for 2 h and phosphate buffer ph 6 . 8 ( usp 32 ) for 8 h ( complete medium change after 2 h ). at pre - determined time points , 3 ml samples were withdrawn ( replaced with fresh medium ), filtered and analyzed uv - spectrophotometrically as described above . excess amounts of 5 aminosalicylic acid were placed in contact with 0 . 1 n hcl and phosphate buffer ph 6 . 8 at 37 ° c . in a horizontal shaker ( 80 rpm , gfl 3033 ). samples were withdrawn every 12 h , filtered and analyzed for their drug content as described in section 2 . 4 . until equilibrium was reached . thermograms of different types of pellets and raw materials ( for reasons of comparison ) were measured by differential scanning calorimetry ( dsc1 ; stare software ; mettler toledo sas , viroflay , france ). pellets were gently crushed in a mortar with a pestle and approximately 7 mg samples were heated in sealed aluminum pans ( investigated temperature range : 20 to 90 ° c ., heating rate : 10 ° c ./ min ). extrusion - spheronisation allowed obtaining spherical pellets in all cases . the systems contained 60 % 5 asa , 15 % ips and 25 % lipid ( s ) ( optionally partially replaced by mcc or pvp ). the high drug loading is of great practical importance , because 5 asa is highly dosed ( up to 4 . 8 g per day ). the presence of ips in the pellets aims at providing colon specific drug delivery : this polymer has been reported to be degraded by enzymes present in feces of inflammatory bowel disease patients . the lipids , mcc and pvp aim at avoiding immediate drug release upon contact with aqueous body fluids ( note that the drug and ips are both water soluble at 37 ° c .). fig1 shows the release of 5 asa from pellets containing 25 % ( w / w ) of the following lipids : ( a ) hardened soybean oil , ( b ) glyceryl tristearate , ( c ) sasolwax ® or synthetic wax , or ( d ) microwax ® hg or microwax ® hw . the systems were cured at different temperatures for 1 , 2 or 3 min ( as indicated ) in order to allow for a more homogeneous lipid distribution , more efficient embedding of the drug particles and eventually the ( partial ) transformation of a lipid into a more stable modification . the melting points of the investigated lipids ( glyceryl tristearate : 70 - 73 ° c ., hardened soybean oil : 67 72 ° c ., sasolwax ®: 96 100 ° c ., synthetic wax : 94 97 ° c ., microwax ® hg : 80 86 ° c ., microwax ® hw : 75 80 ° c .) were close to or well below the investigated curing temperatures . as it can be seen in fig1 , immediate drug release is avoided and the release rate generally decreased with increasing curing temperature and time , irrespective of the type of lipid . thus , in principle the applied strategy is successful . however , in all cases drug release was too rapid and most of the drug was released during the observation period ( corresponding to the simulated transit period through the upper git ; note that long residence times have been assumed , simulating unfavorable conditions for the drug delivery system ). hence , premature drug release in vivo is highly likely . the fact that after complete medium change ( at t = 2 h ), the release rate decreased in most cases can probably ( at least partially ) be attributed to the lower aqueous solubility of 5 asa in phosphate buffer ph 6 . 8 compared to 0 . 1 n hcl at 37 ° c . : 4 . 4 mg / ml versus 10 mg / ml . in order to reduce the undesired premature drug release in 0 . 1 n hcl and phosphate buffer ph 6 . 8 , parts of the lipid were substituted by mcc or pvp . fig2 shows 5 - asa release from pellets containing 60 % drug , 15 % ips , 15 % hardened soybean oil and 10 % mcc or pvp . for reasons of comparison , also drug release from mcc / pvp - free systems ( containing 25 % hardened soybean oil ) is shown . all pellets were cured for 3 min at 70 , 80 or 90 ° c . ( as indicated ). interestingly , the replacement of 10 % ( w / w , referred to the total system mass ) lipid by mcc resulted in accelerated drug release , irrespective of the curing conditions . thus , the lipid is more efficient in hindering drug release from these pellets than mcc . in contrast , the partial replacement of hardened soybean oil by pvp led to slightly / moderately decreased drug release rates , if the systems were cured at 70 and 80 ° c . however , upon curing at 90 ° c ., also in this case drug release was accelerated upon lipid substitution . thus , these approaches are not suitable to effectively minimize premature drug release in the upper git . in a further attempt to avoid the observed undesired drug release in 0 . 1 n hcl and phosphate buffer ph 6 . 8 , a short term curing for 3 min at 90 ° c . was followed by a long term curing at 40 ° c . for 7 days . fig3 shows 5 - asa release from pellets containing 25 % glyceryl trimyristate , hardened soybean oil , glyceryl behenate , glyceryl palmitostearate , glyceryl tripalmitate , hydrogenated cottonseed oil , or glyceryl tristearate upon exposure to 0 . 1 n hcl for 2 h , followed by phosphate buffer ph 6 . 8 for 8 h ( dotted curves ). for reasons of comparison , also drug release from pellets , which were only cured for 3 min at 90 ° c . are shown ( solid curves ). clearly , the release rate significantly decreased in most cases upon long term curing . this can at least partially be attributed to changes in the modifications of the lipids : fig4 shows exemplarily dsc thermograms of pellets consisting of 60 % 5 - asa , 15 % ips and 25 % glyceryl palmitostearate or tripalmitate ( as indicated ). the pellets were cured for 3 min at 90 ° c . and optionally subsequently for 7 days at 40 ° c . for reasons of comparison , also thermograms of 5 - asa , ips and of the lipid powders as received are shown in fig4 . the melting peaks of the powders as received correspond to the melting peaks of the stable β - modifications of these lipids . in contrast , pellets which were only cured for 3 min at 90 ° c . also showed the melting / transformation of a less stable modification , irrespective of the type of lipid . importantly , pellets cured for 7 days at 40 ° c . again only showed the melting of the stable lipid modification ( in both cases ). it has to be pointed out that the curing temperature during long term curing was well below the melting point of the respective lipids . hence , the observed changes in the resulting drug release rates during long term curing are probably not caused by potential redistributions of the lipids . as lipids were used to slow down drug release within the upper part of the git , it was important to measure the effects of the presence of enzymes in the bulk fluids on drug release . fig5 shows 5 - asa release from pellets consisting of 60 % drug , 15 % ips and 25 % hydrogenated cottonseed oil , glyceryl tripalmitate or glyceryl palmitostearate ( as indicated ). the release medium was either 0 . 1 n hcl for the first 2 h , followed by phosphate buffer ph 6 . 8 for the subsequent 8 h ( solid curves ), or 0 . 1 n hcl containing 0 . 32 % w / v pepsin for the first 2 h , followed by phosphate buffer ph 6 . 8 containing 1 % w / v pancreatin for the subsequent 8 h ( dotted curves ). all pellets were cured for 3 min at 90 ° c ., followed by 7 days at 40 ° c . clearly , drug release significantly increased in the presence of enzymes in the case of hydrogenated cottonseed oil and glyceryl tripalmitate , due to the ( at least partial ) degradation of these lipids . in contrast , the release rate only slightly increased in the case of glyceryl palmitostearate . thus , this lipid seems to be much less affected by the added enzymes under these conditions . for this reason , glyceryl palmitostearate was used as standard lipid in all further experiments ( if not otherwise stated ). when developing controlled drug delivery systems , special care needs to be taken with respect to potential changes in the systems &# 39 ; properties during long term storage . modifications in the molecular structures might alter the resulting matrix permeability for the drug and , thus , the release rate . for these reasons , it is of great practical importance to measure drug release before and after long term storage from such dosage forms . storage under stress conditions ( e . g ., elevated temperature ) can allow obtaining results more rapidly than under ambient conditions . fig6 shows the release of 5 - asa from pellets consisting of 60 % drug , 15 % ips and 25 % glyceryl palmitostearate . the pellets were cured for 3 min at 90 ° c ., followed by 7 days at 37 , 40 and 45 ° c . ( as indicated ) ( the melting range of glyceryl palmitostearate is 53 57 ° c .). for reasons of comparison , also drug release from pellets , which were only cured for 3 min at 90 ° c . and from pellets , which were cured for 3 min at 90 ° c ., followed by 6 months at 37 , 40 and 45 ° c . is illustrated . clearly , a days curing is required to slow down drug release , irrespective of the curing temperature . interestingly , the resulting release profiles do not overlap , indicating possible differences in the lipid distribution within the system . importantly , drug release further slowed down when increasing the curing period to 6 months in the case of curing at 37 ° c ., but not in the case of curing at 40 or 45 ° c . thus , the latter pellets are likely to be stable during long term storage at room temperature . as an alternative to matrix pellets , also mini tablets ( diameter : 2 mm ; height : 2 mm ) consisting of 50 % 5 - asa , 15 % ips and 35 % lipid were prepared . again , the high drug loading was important because of the high daily doses of 5 - asa . ips was the colon targeting compound and the lipid was intended to minimize drug release in the upper git . to evaluate the suitability of different types of lipids in these dosage forms , hardened soybean oil , glyceryl tristearate , glyceryl tripalmitate , glyceryl behenate , glyceryl palmitostearate , hydrogenated cottonseed oil as well as hydrogenated soybean oil were studied ( fig7 ). the mini tablets were prepared by direct compression , followed by a curing for 24 or 48 h at 60 , 65 , 70 or 75 ° c . ( as indicated ), according to the melting points of the lipids : hardened soybean oil 67 72 ° c ., glyceryl tristearate 70 73 ° c ., glyceryl tripalmitate 63 ° c ., glyceryl behenate 69 74 ° c ., glyceryl palmitostearate 53 57 ° c ., hydrogenated cottonseed oil 60 62 . 5 ° c . hydrogenated soybean oil 66 . 5 69 . 5 ° c . as it can be seen in fig7 , drug release upon 2 h exposure to 0 . 1 n hcl , followed by 8 h exposure to phosphate buffer ph 6 . 8 is considerable in all cases . generally , the release rate decreased with increasing curing time and temperature , due to altered lipid modifications and / or lipid distribution within the system . as in the case of matrix pellets , glyceryl palmitostearate showed the most promising potential as release rate controlling lipid . for this reason it was studied in more detail . in order to minimize the undesired , premature drug release in the upper git , the curing time and temperature were further increased . fig8 shows 5 - asa release from mini tablets consisting of 50 % drug , 15 % ips and 35 % glyceryl palmitostearate . the systems were cured for 3 min at 90 ° c ., followed by 7 days , 14 days or 1 month at 40 ° c ., or by 12 , 24 or 48 h at 60 ° c . for reasons of comparison , also 5 - asa release from mini tablets cured for 24 h at 60 ° c . is shown . clearly , the release rate was not very much affected by the curing conditions , except for the 1 month curing . as the latter is difficult to realize at an industrial scale and as the release rate still remains considerable , this approach was not further investigated . since the distribution of the lipid within the mini tablets can be expected to significantly alter its ability to hinder drug release , four different preparation techniques were studied , which are likely to result in a more or less intense embedding of the drug within the glyceryl palmitostearate : ( i ) direct compression , ( ii ) partial melt granulation & amp ; compression , ( iii ) separate melt granulation & amp ; compression , and ( iv ) melt granulation & amp ; compression . in the case of “ partial melt granulation & amp ; compression ”, 5 - asa , ips and 60 % of the glycerol palmitostearate were molten at 85 ° c . on a water bath , cooled down to room temperature , ball milled and sieved ( fraction 50 - 100 μm ). the obtained powder was blended with the remaining glyceryl palmitostearate and compressed . in the case of “ separate melt granulation & amp ; compression ”, glyceryl palmitostearate and ips were blended in equal parts and molten at 85 ° c . on a water bath . the remaining glyceryl palmitostearate was blended with the drug and also this blend was molten at 85 ° c . on a water bath . both melts were cooled down to room temperature , ball milled , sieved ( fraction 50 - 100 μm ), blended and compressed . in the case of “ melt granulation & amp ; compression ”, all compounds were molten together at 85 ° c . on a water bath , cooled down to room temperature , ball milled , sieved ( fraction 50 - 100 μm ) and compressed . the mini tablets were optionally cured for 24 h at 60 ° c . as it can be seen in fig9 , the drug release rate decreased in the following ranking order : direct compression & gt ; partial melt granulation & amp ; compression & gt ; separate melt granulation & amp ; compression & gt ; melt granulation & amp ; compression . this was true for uncured as well as for cured mini tablets and can probably be attributed to a more and more intense embedding of the drug within the lipid . as also chitosan has been reported to allow for site specific drug delivery to the colon , the partial substitution of glyceryl palmitostearate by chitosan was studied . fig1 shows drug release from mini tablets consisting of 50 % asa , 15 % ips , 30 % glyceryl palmitostearate and 5 % chitosan . for reasons of comparison , also drug release from mini tablets free of chitosan ( containing 35 % glyceryl palmitostearate ) is shown . all systems were prepared by melt granulation & amp ; compression . the tablets were either uncured or cured for 24 h at 60 ° c . ( as indicated ). clearly , the presence of only 5 % chitosan significantly increased the resulting drug release rate , leading to undesired , premature drug release . this was true for uncured as well as for cured tablets and can be attributed to the higher permeability of the hydrogel chitosan for the low molecular weight drug 5 - asa and / or rapid leaching of this compound into the surrounding bulk fluid at low ph . it has to be pointed out that an enteric coating can avoid an undesired dissolution of chitosan at low ph . such composition is suitable for a use in a coated form . fig1 shows the effects of the ips content ( while keeping the “ ips + glyceryl palmintostearate content ” constant at 50 %) and of the curing conditions on the resulting drug release kinetics from mini tablets prepared by melt granulation & amp ; compression upon exposure to 0 . 1 n hcl for 2 h and subsequent exposure to phosphate buffer ph 6 . 8 for 8 h . the ips content was increased from 15 to 25 % ( while the glyceryl palmitostearate content was decreased from 35 to 25 %), the tablets were optionally cured for 24 or 48 h at 60 ° c . ( as indicated ). as it can be seen , the release rate increased with increasing ips content , because glyceryl palmitostearate is more effectively hindering drug release than ips . note that ips is more effectively hindering drug release than chitosan in this type of dosage forms : when comparing 5 - asa release from mini tablets cured for 24 h at 60 ° c ., containing 50 % drug , 30 % glyceryl palmitostaerate and 20 % ips ( open squares and solid curves in fig1 ) versus 15 % ips + 5 % chitosan ( open squares in fig1 ), it can be seen that drug release was slower in the case of 20 % ips . furthermore , the release rate decreased with increasing curing temperature and time , irrespective of the ips content ( fig1 ). importantly , at a ips level of 15 %, 5 - asa release from mini tablets cured at 60 ° c . for 24 and 48 h is virtually overlapping ( open triangles : dotted and solid curves ), indicating that a stable system is likely to be achieved . thus , mini tablets consisting of 50 % 5 - asa , 15 % ips and 35 % glyceryl palmitostearate prepared by melt granulation & amp ; compression and subsequent curing for 24 h at 60 ° c . show an interesting potential for colon specific drug delivery .
a controlled - release oral pharmaceutical composition of at least an active agent , including : a ) a lipophilic matrix consisting of lipophilic compounds and / or amphiphilic compounds ; and b ) an hydrophilic matrix , wherein the hydrophilic matrix includes at least an indigestible polysaccharide , the active ingredient being dispersed in the lipophilic and / or the hydrophilic matrix . the present invention also relates to a process for the preparation of such a pharmaceutical composition .