EP1485071A2

EP1485071A2 - Compressed tablets comprising microcapsules with modified release

Info

Publication number: EP1485071A2
Application number: EP03744400A
Authority: EP
Inventors: Rafa[L Jorda; Pierre Autant
Original assignee: Flamel Technologies SA
Current assignee: Flamel Technologies SA
Priority date: 2002-03-18
Filing date: 2003-03-14
Publication date: 2004-12-15
Also published as: AU2003242818B2; US8507003B2; CA2479057A1; AU2003242818A1; IL163813A0; US20050266078A1; WO2003077888A3; KR20040105773A; CA2479057C; ZA200408412B; MXPA04009010A; BR0308487A; IL163813A; FR2837100A1; WO2003077888A2; FR2837100B1; CN1642530A; JP2005527522A

Abstract

The aim of the invention is to provide a multi(micro)particulate compressed tablet which comprises a non-mechanically-deformable active principle core (crystal, granule) and which allows the prolonged in vivo release of said active principle, without the release profile being modified by the compression (microparticles not specifically formulated for the compression). Said aim is achieved with the inventive compressed tablet comprising reservoir-type microcapsules with prolonged release of the active principle. According to the invention, each of said microcapsules is formed by a non-deformable core comprising the active principle and covered by at least one coating film which controls the prolonged in vivo release of the active principle. Moreover, each microcapsule has a particle size distribution of between 50 and 1,000 ñm and comprises at least one outer overcoating envelope which is based on at least one deformable organic component having a melting temperature of between 40 DEG C and 120 DEG C (polyethylene glycol). The invention also relates to the overcoated microcapsules which are resistant to compression.

Description

TABLETS BASED ON MODIFIED RELEASE MICROCAPSULES

The field of the present invention is that of multi (micro) particulate tablets, preferably orodispersible, allowing the implementation of active principles (PA) preferably highly dosed.

In particular, the present invention relates to tablets, preferably orodispersible, based on reservoir-type microcapsules, allowing the sustained release in vivo of at least one medicinal and / or nutritional active principle (PA), these microcapsules constituting the tablets being of the type of those • formed by hard PA cores each covered by at least one coating film controlling the prolonged in vivo release of the PA, • and having a particle size between 50 and 1000 microns, preferably between 100 and 750 microns, and, more preferably still, between 200 and 500 microns, and, on the other hand, a specific overcoating. The invention also relates to these microcapsules constituting prolonged-release tablets preferably, rapidly orodispersible and highly dosed with active principle.

Multiparticulate sustained release systems for drug delivery are well known. In particular, French patent application FR-A-2 725 623 (FLAMEL-

TECHNOLOGIES) relates to a multi-microparticulate galenic system with prolonged release of AP. This system consists of microcapsules intended for oral administration, for a prolonged period, of at least one active principle (excluding acetylsalicylic acid). These microcapsules are formed by a core of active principle, coated with a coating based for example on ethylcellulose, polyvinylpyrrolidone, castor oil and magnesium stearate. These microcapsules are quite efficient with regard to the prolonged release of the AP in vivo. However, even if this coating perfectly exercises its function of prolonged release, it nevertheless remains perfectible as regards the capacity for compression of such microcapsules. Indeed, the excipients used in this coating controlling the prolonged release of the AP, poorly withstand the mechanical stresses imposed during compression. This results in an alteration of said coating and consequently a disruption of its function for controlling the prolonged release of the AP.

This is so in the invention which is the subject of European patent EP-B-0 548 356 modified in the course of opposition and covering a multiparticulate tablet with rapid disintegration comprising an active substance in the form of microcrystals or microgranules provided with a coating ensuring for example masking of taste and a mixture of excipients, which is free of effervescent agents, organic acids and agents developing a high viscosity in contact with water, said mixture of excipients comprising one or more disintegrating agents of the insoluble cross-linked carboxymethylcellulose or polyvinylpyrrolidone type and one or more swelling or soluble agents, said swelling agent being of the starch, modified starch or microcrystalline cellulose type, said tablet disintegrating in the absence of any chewing action in less than 60 seconds when placed in the mouth, providing with saliva presents a suspension easy to swallow.

The patent US-A-5, 464.632 corresponding to EP-B-0 548 356, relates to a rapidly disintegrating tablet in the oral cavity without the use of water, this tablet:

- comprising an active substance and a mixture of non-effervescent excipients

- and allowing to obtain a reduced influence on the pH in the digestive tract as well as a reduced influence of viscosity, this active substance being multiparticulate in the form of coated microcrystals or coated microgranules, said mixture of excipients comprising an agent disintegrant and a blowing agent which are responsible for the disintegration of the tablet with the saliva present in the mouth, to obtain in less than 60 seconds an easy-to-swallow suspension.

The orodispersible tablets according to these patents do not offer all the desirable guarantees as regards the preservation of the functions of prolonged release of the PA and / or of masking of taste, during compression.

This problem of compressibility of coated AP microparticles is well known in the prior art. It is mentioned in particular in: "International Journal of Pharmaceutics, No 143, 13-23 (1996)", as well as in the international PCT application WO-99/26608. It is specified in these documents that the compression of coated granules modifies the structure of the coating film by the appearance of cracks or by rupture, which leads to the partial or total loss of the properties of the coating film. In particular, cracking irreversibly changes the release profile of the active ingredient (s) they contain. The invention described in this previous application WO-99/26608, proposes to remedy this problem by providing compressible spheroids containing one or more active ingredients with the exception of tiagabine, directly compressible without the addition of a substantial part. an auxiliary substance, i.e. less than 5% by weight, preferably less than 1% by weight. These spheroids comprise a core coated with a coating layer. The core and / or the coating layer contains (nen) t at least one active principle and at least one thermoplastic excipient of pasty to semi-solid consistency at a temperature of 20 ° C, and a melting temperature between 25 and 100 ° C.

This set containing the active principle (s) is coated with a flexible deformable film based on a polymer material with a glass transition temperature below 30 ° C. and which provides either protection or masking of the taste. , or the modified and controlled release of the active ingredient (s). In Example 2 of O-A-99/26608, spheroids are prepared comprising:

- a sugar-neutral core;

- a deformable layer of active principle (codeine) assembled with a polyethylene glycol: PEG 6000, wax, a surfactant: TWEEN® 80 dl-α-tocopherol, and talc;

- a deformable coating based on a permeable swelling film based on polyacrylate (eudragit® NE 30 D) and a polyethylene glycol: PEG 6000, eudragit® NE 30 D being a neutral ester of polyacrylic or polymethacrylic acid;

- a deformable outer layer comprising OPADRY® II (combination of polymers and polysaccharides) and polyethylene glyco PEG 6000.

These spheroids are specifically designed with several soft layers, which more specifically makes them suitable for obtaining tablets dispersible in solution, to the exclusion of orodispersible tablets of the type of those defined in EP-B-0 548 356.

In addition, the outer layer aims to make tablets without the addition of auxiliary substances and has the role of ensuring the cohesion of the spheroids between them, ensuring the hardness of the tablet and allowing its disintegration when is immersed in solution

These spheroids ultimately contain only 8.2% by weight of PA: codeine. These spheroids can be transformed into tablets with a hardness equal to 20 N. In addition, it should be noted that the levels of active principle in the spheroids according to WO-A-99/22608 are extremely limited. This constitutes a major handicap with regard to compliance (compliance with the dosage) for patients, when the PAs concerned must be strongly dosed in the tablet obtained from these spheroids. Indeed, to reach the prescribed dose per tablet with a low PA load rate, it is then necessary to produce an extremely bulky tablet, therefore difficult to swallow, especially for elderly and / or weak patients. Under such conditions, the success of treatments is most uncertain. Finally, obtaining tablets without altering the dissolution or minimizing the alteration in the dissolution of the spheroids requires a specific formulation of said spheroids and their coating and cannot be envisaged from microcapsules which do not, intrinsically, have the required flexibility characteristics.

It emerges from this review of the state of the art that it is difficult to find a technical compromise guaranteeing both the stability of the release profile of the AP between the form "compressed microcapsules" and the form "non-compressed microcapsules" and maintaining the mechanical properties of the microcapsules allowing their compressibility. In the solutions already proposed, microcapsules are constructed having several deformable layers. This leads to difficulties in developing the release profile and obtaining products very diluted in active and therefore low in PA content.

In addition, contrary to what is known, it would be desirable in the approach to the problem, not to fully design a system of microcapsules, but rather a simple technical proposal, adaptable to any microcapsule or microsphere.

In such a state of the art, one of the essential objectives of the present invention is to provide a multi (micro) particulate tablet, preferably orodispersible, comprising one or more active ingredients capable of being highly dosed, allowing prolonged release. in vivo of this (or these) active principle (s), and whose release profile is not significantly modified by compression, without the microparticles having been specifically formulated for compression, as regards the part containing the active principle (s) and the coating ensuring the control of the dissolution.

Another essential objective of the present invention is to provide a tablet, preferably orodispersible and based on reservoir-type microcapsules, comprising a core of mechanically non-deformable active principle (crystals, granules), allowing the sustained release in vivo of this (or these) active ingredient (s), the release profile of which is not significantly modified by compression.

Another essential objective of the present invention is to provide a tablet, preferably orodispersible and based on reservoir-type microcapsules, comprising a core of hard active principle, ie mechanically non-deformable (crystals, granules), the release profile of which does not is not changed significantly by compression.

Another essential objective of the present invention is to provide a tablet, preferably orodispersible and based on reservoir-type microcapsules, comprising a core of mechanically non-deformable active principle (crystals, granules), allowing prolonged in vivo release of this (or these) active principle (s), the release profile of which is not significantly modified by compression, and of suitable hardness, preferably greater than 20 N. Another essential objective of the present invention is to provide reservoir-type microcapsules, comprising at least one AP, which can be administered orally and which allow the sustained release of the PA in vivo, these microcapsules comprising in addition, a core of mechanically non-deformable active ingredient (crystals, granules), which can be directly compressed without modifying the release profile. Another essential objective of the present invention is to propose the use of the microcapsules referred to in the abovementioned objectives, for the preparation of pharmaceutical or dietetic forms (preferably tablets, for example disintegrable or orodispersible).

These objectives, among others, are achieved by the present invention which proceeds from the principle of dissociation of the functions of controlled release and of resistance to compression within a same microcapsule. In other words, it is advantageously proposed, in accordance with the invention, to use as such as raw materials, microcapsules developed exclusively with respect to a therapeutic objective of release profile, which is coated with a protective layer which will absorb the mechanical stresses due to the compression operation. This approach allows us to answer the following points:

- possibility of obtaining very specific release profiles, optimization of the stability of microcapsules and maintenance of their properties after compression,

- possibility of access to highly dosed active ingredients.

Hence it follows that the present invention relates first of all to a tablet, preferably orodispersible, based on reservoir-type microcapsules, allowing the sustained release in vivo of at least one medicinal and / or nutritional active principle ( PA), these microcapsules constituting the tablet being of the type of those:

• each formed by a non-deformable core comprising PA and covered by at least one coating film controlling the prolonged in vivo release of PA, • and having a particle size between 50 and 1000 microns, preferably between 100 and 750 microns , and, more preferably still, between 200 and 500 microns, characterized in that these microcapsules comprise at least one external overcoating envelope based on at least one deformable organic constituent having a melting temperature between 40 ° C and 120 ° C, preferably between 45 ° C and 110 ° C.

Without being limiting, the new galenic system with prolonged release formed by this preferably orodispersible tablet is particularly advantageous for active ingredients which are highly dosed.

With the microcapsules constituting the tablet according to the invention, the galenists have in particular a tool allowing them to produce a tablet containing a single and high nycthemeral dose of PA, and this for a large number of PAs.

Indeed, the overcoating which constitutes one of the essential structural characteristics of the microcapsules used in the tablet of the invention, provides mechanical resistance during compression, without however affecting the prolonged release properties conferred by the coating. of the PA core of said microcapsules.

The dissociation of the functions of protection and control of the release of the AP within distinct layers of the microcapsules is one of the keys to the stability of these at compression.

Within the meaning of the invention:

- the qualifier "non-deformable" or "hard" refers, in the case of particles comprising the PA (s), to behavior in a specific compression test Te, such that the mass percentage of release / dissolution is at least 20 % higher, for the particles having undergone the Te compression test compared to the mass percentage of release / dissolution observed for the same particles which have not undergone the compression test.

The Te test is defined below in the introductory part of the examples. - The term "orodispersible" indicates the property of the tablet to be able to disintegrate in the mouth quickly, simply with the help of saliva, to form an easily swallowed suspension. The term "microcapsules" denotes film-coated submillimetric particles of the reservoir type, as opposed to microspheres of the matrix type. These microcapsules can be likened to vehicles allowing the transport and the release of one or more AP in the absorption window of the small intestine. The microcapsules which are obtained after lamination of hard cores are a priori non-deformable (therefore not resistant to compression). This hardness and the non-deformability character translate in the compression test Te by the fact that the quantity of PA released at a given time increases sharply after compression of these microcapsules (see introduction of the examples).

According to a preferred characteristic of the invention, the concentration of deformable organic constituent in the overcoating is greater than or equal to 10% by weight, preferably between 20 and 100% by weight.

The external overcoating envelope, specific to the microcapsules used in the tablet according to the invention, derives part of its originality from the fact that it results from a judicious selection of the deformable constituent from the organic compounds having a melting temperature. between 40 and 120 ° C, these compounds being chosen:

• among the polymers and copolymers based on alkylene glycol, polyethylene glycol being particularly preferred, and in particular polyethylene glycols having a molecular weight of 6000 to 20,000 D, • and / or among fatty substances such as vegetable oils hydrogenated, fatty acids, fatty alcohols, fatty acid and / or fatty alcohol esters, polyolefins and mineral, vegetable, animal or synthetic waxes, fatty acid esters such as di- and triglycerides and their mixtures, glycerol behenate as well as hydrogenated oils, hydrogenated castor, soybean, cotton and palm oils being particularly preferred in accordance with the invention.

The said organic constituent (s) of overcoating, the melting point of which is advantageously between 40 and 120 ° C. can (can) advantageously be used alone or as a mixture between them, and optionally in combination: with a mineral filler such as silica or titanium dioxide for example or organic fillers such as microcrystalline cellulose for example, 4 and / or with at least one lubricant such as magnesium stearate or sodium benzoate for example, * and / or with at least one hydrophilic polymer such as water-soluble derivatives of cellulose such as hydroxypropyl cellulose or hydroxypropyl methyl cellulose, and synthetic polymers such as polyvinylpyrrolidone or polyvinyl alcohols (APN) or acrylic and methacrylic derivatives such as EUDRAGIT® for example, and / or a surfactant such as polyoxyethylene sorbitan® esters for example.

This plastically deformable overcoating is advantageous for several reasons. First of all, it is preferably an excipient or a mixture of conventional pharmaceutical excipient (s).

The overcoating according to the invention also has the advantage of protecting against any irritation of the mucous membranes and of being achievable in a simple and economical manner.

The microcapsules used in the tablet of the invention are all the more advantageous since they are perfectly tolerated by the organism, especially in gastric fluids and can be prepared by conventional methods of the pharmaceutical industry. .

According to a preferred characteristic of the invention, the external overcoating envelope represents from 5 to 50%, preferably from 10 to 30%, and more preferably still of the order of 20% by dry weight of the total mass of microcapsules. According to a preferred characteristic of the invention, the PA particles are chosen from hard PA mechanically non-deformable hearts, these hearts being preferably selected from the group comprising crystals or granules.

With regard to the qualitative and quantitative composition of the coating film, it can in particular be as follows:

1 - at least one film-forming polymer (PI) insoluble in the fluids of the tract, present in an amount of 50 to 90, preferably 50 to 80% by dry weight relative to the total mass of the coating composition and consisting of at least one non-water-soluble derivative of cellulose, ethylcellulose and / or cellulose acetate being particularly preferred;

2 - at least one nitrogen-containing polymer (P2) present in an amount of 2 to 25, preferably 5 to 15% by dry weight relative to the total mass of the coating composition and consisting of at least one polyacrylamide and / or a poly-Ν-vinylamide and / or a poly-Νvinyl-lactam, polyacrylamide and / or polyvinyipyrrolidone being particularly preferred;

3 - at least one plasticizer present in an amount of 2 to 20, preferably 4 to 15% by weight on a dry basis relative to the total mass of the coating composition and consisting of at least one of the following compounds: glycerol esters, phthalates, citrates, sebacates, cetyl alcohol esters, castor oil, salicylic acid and cutin, castor oil being particularly preferred; 4 - at least one surfactant and / or lubricant, present in an amount of 2 to 20, preferably from 4 to 15% by weight on a dry basis relative to the total mass of the coating composition and chosen from surfactants anionic active agents, preferably the alkaline or alkaline earth salts of fatty acids, stearic and / or oleic acid being preferred, and / or among nonionic surfactants, preferably polyoxyethylenated sorbitan esters and / or derivatives of polyoxyethylenated castor oil, and / or among lubricating agents such as stearates, preferably calcium, magnesium, aluminum or zinc, or such as stearyl fumarate, preferably sodium, and / or glycerol behenate ; said agent possibly comprising a single or a mixture of the above products.

In practice, the composition of the coating film for the microcapsules could comprise, for example, from 60 to 80% of ethylcellulose, from 5 to 10% of polyvinylpyrrolidone, from 5 to 10% of castor oil and from 2 to 8% of magnesium stearate. For more details on this coating for controlling the prolonged release of the AP, reference is made to FR-A-2 725 623, the content of which is fully included in the present description.

It should however be noted that the invention can be advantageously implemented from microcapsules of very diverse compositions and in particular with microcapsules which have not been specifically formulated with a view to their compression, for example in the form of orodispersible tablets.

According to a preferred embodiment of the invention, the microcapsules have the following weight composition (% by weight on a dry basis):

- PA-based particles: from 50 to 80; preferably from 55 to 65, - coating film: from 10 to 30; preferably from 15 to 25,

- overcoating envelope: from 10 to 30; preferably from 15 to 25.

According to an advantageous variant of the invention, the overcoated microcapsules can comprise an amount of AP> 50% by weight on a dry basis relative to their total mass.

Thanks to such active ingredient loading rates, it is possible to envisage the production of tablets of suitable size, easy to swallow and comprising in each unit the high daily dose of PA required for the patient. This greatly facilitates the patient's compliance with the dosage and therefore the success of the treatment.

The compressibility characteristic of the overcoated microcapsules according to the invention is all the more advantageous as it allows access to cohesive and non-friable tablets, for example having a hardness D> 20 N.

The AP used for the preparation of the tablets according to the invention can be chosen without limitation, from at least one of the following large varieties of active substances: antiulcer, antidiabetic, anticoagulant, antithrombic, lipid-lowering, antiarrhythmic, vasodilator, antianginal, antihypertensive, vasoprotectors, fertility promoters, inducers and inhibitors of uterine labor, contraceptives, antibiotics, antifungals, antivirals, anticancer drugs, anti inflammatories, analgesics, antiepileptics, antiparkinsonians, neuroleptics, hypnotics, anxiolytics, psychostimulants, antimigraine medications, antidepressants, antidepressants, antitressants, anti-depressants, anti-depressants.

Among the preferred medicinal APs according to the invention, there may be mentioned: pentoxifylline, prazosine, acyclovir, nifedipine, diltiazem, naproxen, ibuprofen, flurbiprofen, ketoprofen, fenoprofen, indomethacin, diclofenac, fentiazac, estradiol valerate, metoprol, metoprol , zidovudine, nicardipine, terfenadine, atenolol, salbutamol, carbamazepine, ranitidine, enalapril, simvastatin, fluoxetine, alprazolam, famotidine, ganciclovir, famciclovir, spironolactone, 5-asa, quinidine, perindopriline, morphine pentopoline, pentin , metformin and their mixtures.

The active principles also concerned by the invention can be selected from nutritional and / or dietetic supplements or their mixtures, such as for example vitamins, amino acids, antioxidants, trace elements or their mixtures.

In general, the mechanically deformable overcoating, leading to the microcapsules used in the tablet according to the invention, is carried out by conventional techniques such as, for example, the spraying of the constituents of the overcoating in solution, in suspension, in emulsion or in molten state in film-coating devices such as fluidized air beds or film-coating turbines, or for example by hot mixing of the microparticles with the constituents of the overcoating taken in powder form, in suitable devices such as spheronizers, or kneaders, or for example by techniques of coacervation and / or phase separation. Some of these techniques are summarized in the article by C. DUNERNEY and JP BENOIT in "L'actualité Chimique", December 1986.

The overcoated microcapsules making up the tablet according to the invention carry technical characteristics allowing access to the maintenance of the release profiles, after compression, even for highly dosed PAs. They therefore form in themselves an object of the present invention. These overcoated microcapsules are as defined above with reference to the description of the tablet.

The overcoated microcapsules according to the invention, obtained after coating of hard and non-deformable microparticles as defined in the introductory part of the examples, are perfectly resistant to compression. This resistance results from the compression test Te carried out on this type of overcoated microcapsules where it clearly appears that the quantity of PA released at a given time does not change after compression of these microcapsules.

Another object of the invention is the use of overcoated microcapsules as defined above for the preparation of pharmaceutical or dietetic forms, preferably in the form of tablets which are advantageously disintegrable in the mouth (orodispersible), film-coated tablets, tablets dispersible or effervescent tablets.

Advantageously, the orodispersible tablets according to the invention have this particular, that they only comprise, as an operational excipient in the rapid disintegration of the tablet in the mouth, only a disintegrating agent to the exclusion of any swelling agent.

Such tablets can be administered orally, preferably as a single daily dose.

It should be noted that it may be advantageous to mix in the same tablet, at least two different types of AP, at least one of which is present in the form of overcoated microcapsules according to the invention. The differences may relate to the nature of the active principle and / or to the release profile defined by the coating. The invention will be better explained by the following examples, given solely by way of illustration and making it possible to understand the invention well and to highlight its variant embodiments, as well as its various advantages.

EXAMPLES

The following examples are intended to illustrate the invention without limitation.

The Te dissolution test used to characterize the tablets according to the invention compared to control tablets, is defined below.

The prolonged-release microcapsules (LP), overcoated according to the invention or not, are mixed with 70% m / m of a disintegrating agent (crospovidone®) then the mixture is put into the form of tablets with a manual press, applying increasing compressive forces. The pressure transmitted to the product via the punch is adjusted by means of a pneumatic cylinder making it possible to precisely adjust the compression force. The punches used are flat, with chamfered edges and a diameter between 5 and 20 mm, depending on the pressure to be transmitted to the powder. Each mixture is thus subjected to pressures ranging from 6 to 150 MPa. The dissolution profile of the manufactured tablets is checked (European Pharmacopoeia device) and the evolution of the rate of active principle released after 1 hour of dissolution is compared, as a function of the pressure applied during compression, for LP microcapsules not overcoated and overcoated according to the invention. Note that the presence of crospovidone® in the mixture makes it possible to avoid the aggregation of the microcapsules with one another during compression, which would result in a parasitic alteration of the dissolution profile.

Examples 1 and 2 make it possible to demonstrate that the microcapsules which can be used in the context of the invention do not resist compression, when they are not previously subjected to overcoating according to the invention.

In Examples 3 to 19, prolonged-release microcapsules (LP), not intrinsically resistant to compression, are prepared, then put into the form of tablets, essentially of the orodispersible type, but also in the form of swallowing tablets, by absence or presence of an overcoating according to the invention. In order to highlight the similarity or the alteration of the dissolution profiles, the comparison method described in SUPAC-MR, CMC 8, September 1997, is used. It is a method of calculating least squares, which leads to the expression of a similarity factor f2, which makes it possible to highlight the identity of the profiles between the reference and the product tested, when the value of f2 is greater than 50, or their difference when the factor f2 is less than 50.

Examples 3 to 19 demonstrate that particles which are not intrinsically resistant to compression can be put into the form of tablets when they are previously overcoated according to the invention.

Description of the figures:

- Figure 1 shows the evolution of the dissolution (release rate of the AP after 1 hour of dissolution) as a function of the pressure exerted on non-overcoated LP microcapsules according to the invention (Example 1).

- Figure 2 shows the evolution of the dissolution depending on the pressure exerted on LP microcapsules previously overcoated according to the invention (Example 2).

- Figures 3 to 7 show the dissolution profiles of the LP microcapsules and of the resulting tablets, in the presence and in the absence of the overcoating according to the invention:

- Figure 3: orodispersible tablets based on microcapsules of metformin hydrochloride sustained release "slow" microcapsules (Example 3) tablet of non-overcoated microcapsules (example 4)

- - -O - - tablet of overcoated microcapsules (example 5)

- Figure 4: orodispersible tablets based on "fast" sustained release metformin hydrochloride microcapsules microcapsules (example 6) tablet of non-overcoated microcapsules (example 7) tablet of overcoated microcapsules (example 8) tablet of overcoated microcapsules (example 9) overcoated microcapsule tablet (example 10)

- Figure 5: orodispersible tablets based on aspirin sustained-release microcapsules - O - microcapsules (example 11)

- • - tablet of non-overcoated microcapsules (example 12)

- - -O - - tablet of overcoated microcapsules (example 13) - Figure 6: swallowing tablets based on metformin hydrochloride extended release microcapsules. microcapsules (example 6) tablet of non-overcoated microcapsules (example 14) - - -O - - tablet of overcoated microcapsules (example 15)

- Figure 7: orodispersible tablets based on prolonged-release aciclovir microcapsules

- O - microcapsules (example 16) tablet of non-overcoated microcapsules (example 17)

- - -O - - tablet of overcoated microcapsules (example 18)

Example 1

Aciclovir granules are prepared by wet granulation in the presence of 3% povidone® K30. The grains are calibrated and then dried in a fluidized air bed. 4500 g of dry granules of aciclovir, of particle size fraction between 200 and 500 μm, are coated with a composition according to patent FR-A-2 725 623, allowing the prolonged release of the active principle, consisting of an ethylcellulose / magnesium stearate / castor oil / PNP: 73.1 / 9.86 / 7.90 / 7.90, in solution in an acetone / isopropyl alcohol mixture: 60/40.

30% m / m of these LP microcapsules are mixed with 70% m / m of crospovidone® (Kollidon® CL). The mixture is compressed in a manual press equipped with a matrix with a diameter of 10.5 mm, then 6.5 mm by means of a jack developing an adjustable force of between 1500 and 4500 Ν. In this way the tablets produced undergo a pressure of between 18 and 150 MPa. In order to preserve the continuity of the stress during the change of matrix, the mass of the tablet is kept proportional to the square of the diameter of the matrix.

Tablets are produced at different pressures. These different tablets are subjected to the dissolution test and the evolution of the dissolution rate after one hour is observed, as a function of the pressure applied during compression. (Dissolution test: Pharm. Eur., Paddle stirrer, speed 100 rpm, in 1000 ml of buffer pH = 6.8) ww The results recorded are presented in the table below.

It is found that the dissolution rate increases when the compression pressure increases, which demonstrates the poor resistance to compression of such microcapsules.

Figure 1 attached shows the dissolution profile obtained.

Example 2:

200 g of the LP coated particles described in Example 1 are overcoated by film coating in a fluidized air bed with a mixture composed of 25 g of hydrogenated castor oil (Cutina ®HR) and 25 g of polyvinylpyrrolidone (Plasdone ® K29 -320), dissolved in 300 g of isopropyl alcohol. The coating parameters are as follows: device: Niro Combi-Coata © CCI temperature of the coating solution: 70 ° C fluidization air flow rate: 15 m ³ / h product temperature: 38 ° C spraying pressure: 0J bar spray air temperature: 70 ° C spray solution flow: 3 g / min As in Example 1, these overcoated LP particles are mixed with 70% m / m of crospovidone®, then compressed at different pressures.

The results recorded are presented in the table below.

Figure 2 attached shows the dissolution profile obtained.

It is noted that the dissolution rate does not increase when the compression pressure increases, which demonstrates that microcapsules which are not intrinsically resistant to compression (see example 1), become resistant when they have been overcoated according to the invention.

Example 3:

Manufacture of LP microcapsules that do not intrinsically have good compressive strength. These particles have a core in the form of a hard and brittle single crystal.

1000 g of metformin hydrochloride crystals, with a particle size between 200 and 500 microns, are coated with a composition according to patent FR-A- 2,725,623, allowing the prolonged release of the active principle, consisting of a mixture of 398.46 g of ethylcellulose (Ethocel®7 premium), 43.08 g of polyvinylpyrrolidone (Plasdone® K29-32) of 43.08 g of castor oil and 53.85 g of magnesium stearate, set suspended in a mixture of 3717 g of acetone and 2476 g of isopropyl alcohol.

The coating is carried out in a fluidized air bed under the following conditions: device: Aeromatic® MPI temperature of the coating solution: ambient temperature fluidization air flow rate: 65 m3 / h product temperature: 40 ° C spraying pressure: 2.3 bars spraying air temperature room temperature sprayed solution flow: 30 g / min

The dissolution profile, determined by the method of the European Pharmacopoeia, paddle stirrer, at 100 revolutions per minute, in 1000 ml of a pH 6.8 buffer is as follows:

TABLE 3

Figure 3 attached shows the profile obtained.

Example 4:

Negative example demonstrating the modification of the dissolution profile by the effect of compression, in the absence of the overcoating according to the invention.

The LP coated particles of Example 3 are put into the form of orodispersible tablets with a Korsch alternative press equipped with a flat punch with a diameter of 18 mm, by mixing with the excipients described below, then direct compression. Tablets containing 500 mg of Metformin HC1.

The dissolution profile of the tablets thus obtained, determined under the same conditions as for the initial particles is as follows:

TABLE 5

Figure 3 attached shows the profile obtained.

The test of similarity of the solutions comparing the microcapsules of Example 3 and the tablet of Example 4 leads to a coefficient f2 of less than 50. The dissolution profile is modified.

Example 5:

Example of overcoating according to the invention and compression of the overcoated LP microcapsules.

200 g of the LP coated particles obtained in Example 3 are overcoated by hot mixing (at around 65-70 ° C) in a 1 liter reactor equipped with mechanical stirring, with 50 g of polyethylene glycol PEG 6000, introduced in powder form. The mixture is heated in order to obtain the melting of the PEG, then gradually cooled with continuously adapted stirring, until a solid fluid powder is obtained.

After overcoating, the dissolution profile of the microcapsules is as follows:

TABLE 6

These overcoated particles are then put into the form of orodispersible tablets with a Korsch alternative press equipped with a flat punch with a diameter of 18 mm, by mixing with the excipients described below, then direct compression. Tablets containing 500 mg of Metformin HC1.

Figure 3 appended shows the dissolution profile obtained for the overcoated microcapsule tablets.

The test of similarity of the solutions comparing the microcapsules of Example 3 and the tablet of Example 5 leads to a coefficient f2 greater than 50. The dissolution profile is not significantly modified.

Example 6:

Manufacture of LP microcapsules which do not intrinsically exhibit good resistance to compression. These particles have a core in the form of a hard and brittle single crystal. 4000 g of metformin hydrochloride crystals, with a particle size between 200 and 500 microns, are film-coated with a composition according to patent FR-A- 2,725,623, allowing the prolonged release of the active principle, consisting of a mixture of 1040.0 g of ethylcellulose (Ethocel 7 premium), 112.4 g of polyvinylpyrrolidone (Plasdone K29-32) of 112.4 g of castor oil and 140.6 g of magnesium stearate, suspended in a mixture of 9700 g of acetone and 6464 g of isopropyl alcohol.

The coating is carried out in a fluidized air bed under the following conditions: device: Aeromatic® MP2 temperature of the coating solution: ambient temperature fluidization air flow rate: 250 m3 / h product temperature: 40 ° C spraying: 2.5 bars temperature of the spraying air: room temperature flow rate of sprayed solution: 150 g / min

The dissolution profile, determined by the method of the European Pharmacopoeia, paddle stirrer, at 100 revolutions per minute, in 1000 ml of a pH 6.8 buffer is as follows: TABLE 9

Figure 4 attached shows the dissolution profile obtained.

Example 7: Negative example demonstrating the modification of the dissolution profile by the effect of compression.

The coated particles LP of Example 6 are put into the form of orodispersible tablets with a Korsch alternative press equipped with a flat punch with a diameter of 18 mm, by mixing with the excipients described below, then direct compression. Tablets containing 500 mg of Metformin HC1.

TABLE 11

Figure 4 attached shows the dissolution profile obtained.

The test of similarity of the solutions comparing the microcapsules of Example 6 and the tablet of Example 7 leads to a coefficient f2 of less than 50. The dissolution profile is modified.

Example 8:

200 g of the LP coated particles described in Example 6 are overcoated by film coating in a fluidized air bed with a mixture composed of 25 g of castor oil hydrogenated (Cutina® HR) and 25 g of polyvinylpyrrolidone (Plasdone® K29-320), dissolved in 300 g of isopropyl alcohol. The coating parameters are as follows: device: Niro Combi-Coata® CCI temperature of the coating solution: 70 ° C fluidization air flow: 15 m3 / h product temperature: 38 ° C spraying pressure: 0J bar spray air temperature: 70 ° C spray solution flow: 3 g / min

The dissolution profile of the overcoated microcapsules is as follows

TABLE 12

These overcoated particles are put into the form of orodispersible tablets with a Korsch alternative press equipped with a flat punch with a diameter of 18 mm, by mixing with the excipients described below, then direct compression.

Tablets containing 500 mg of Metformin HC1.

TABLE 13

TABLE 14

Figure 4 appended shows the dissolution profile obtained for these overcoated microcapsule tablets.

The test of similarity of the solutions comparing the microcapsules of example 6 and the tablet of example 8 leads to a coefficient f2 greater than 50. The dissolution profile is not significantly modified.

Example 9:

200 g of the LP coated particles described in Example 6 are coated with film-coating in a fluidized air bed with 25 g of glycerol tripalmitate (Dynasan®116) and 25 g of polyvinylpyrrolidone (Plasdone® K29-320) in 300 g of isopropyl alcohol The coating parameters are identical to those of Example 8.

The dissolution profile of the overcoated microcapsules is as follows:

TABLE 15

These overcoated particles are put into the form of orodispersible tablets, dosed with 500 mg of metformin HC1, according to the same method and with the same composition as in Example 8.

TABLE 16

The test of similarity of the solutions comparing the microcapsules of Example 6 and the tablet of Example 9 leads to a coefficient f2 greater than 50. The dissolution profile is not significantly modified.

Example 10:

200 g of particles coated with LP of Example 6 are overcoated in a fluidized air bed with a suspension of 15 g of magnesium stearate in a solution of 35 g of PEG 6000 in 88% isopropyl alcohol. The filming conditions are identical to those of Example 8.

The dissolution profile of the overcoated microcapsules is as follows:

TABLE 17

TABLE 18

The similarity of dissolution test comparing the microcapsules of Example 6 and the tablet of Example 10 leads to a coefficient £ 2 greater than 50. The dissolution profile is not significantly modified.

Example 11:

18,000 g of crystals of acetylsalicylic acid (ASA), with a particle size of between 300 and 500 microns, are coated with a composition according to patent FR-A- 2,704,146 (deposit number: 93 04560), allowing the release prolonged active ingredient, consisting of a mixture of 1365.1 g of ethylcellulose (Ethocel® 7 premium), 77 g of polyvinylpyrrolidone (Plasdone® K29-32) of 115.2 g of castor oil of 187, 9 g of tartaric acid and 97.9 g of magnesium stearate, suspended in a mixture of 15,746 g of acetone and 10,519 g of isopropyl alcohol.

The coating parameters are as follows: device: Aeromatic ®MP2 temperature of the coating solution: ambient temperature fluidization air flow: 350 m3 / h product temperature: 40 ° C spraying pressure: 3.5 bars spraying air temperature room temperature sprayed solution flow: 250 g / min

The dissolution profile, determined by the method of the European Pharmacopoeia, paddle stirrer, at 100 revolutions per minute, in 1000 ml of a pH 7.4 buffer is as follows:

TABLE 19

Figure 5 attached shows the dissolution profile obtained for these tablets of non-overcoated microcapsules.

Example 12:

Negative example demonstrating the modification of the dissolution profile by the effect of compression.

The LP coated particles of Example 11 are put into the form of orodispersible tablets with a Korsch alternative press equipped with a flat punch with a diameter of 18 mm, by mixing with the excipients described below, then direct compression.

Tablets dosed at 500 mg of ASA.

TABLE 20

TABLE 21

Figure 5 attached shows the dissolution profile obtained for this tablet of non-overcoated microcapsules.

The test of similarity of the solutions comparing the microcapsules of Example 11 and the tablet of Example 12 leads to a coefficient f2 of less than 50. The dissolution profile is modified.

Example 13:

200 g of the LP coated particles described in Example 11 are overcoated by film coating in a fluidized air bed with a mixture composed of 30 g of hydrogenated castor oil (Cutina HR) and 20 g of polyvinylpyrrolidone (Plasdone K29-320 ), dissolved in 300 g of isopropyl alcohol. The coating parameters are identical to those of Example 8.

The dissolution profile of the overcoated microcapsules is as follows:

TABLE 22

These overcoated particles are put into the form of orodispersible tablets with a Korsch alternative press equipped with a flat punch with a diameter of 18 mm, by mixing with the excipients described below, then direct compression. Tablets dosed at 500 mg of ASA. TABLE 23

TABLE 24

Figure 5 attached shows the dissolution profile obtained for this tablet of overcoated microcapsules.

The test of similarity of the solutions comparing the microcapsules of Example 11 and the tablet of Example 13 leads to a coefficient f2 greater than 50. The dissolution profile is not significantly modified.

Example 14:

Negative example demonstrating the modification of the dissolution profile by the effect of compression, for tablets to be swallowed.

The coated particles LP of Example 6 are put into the form of tablets to be swallowed with a Korsch alternative press equipped with an oblong punch of 19 x 9.5 mm, by mixing with the excipients described below, then direct compression.

Tablets containing 500 mg of metformin HC1. TABLE 25

TABLE 26

Figure 6 attached shows the dissolution profile obtained for these non-overcoated microcapsule tablets.

The test of similarity of the solutions comparing the microcapsules of Example 6 and the tablet of Example 14 leads to a coefficient £ 2 of less than 50. The dissolution profile is modified.

Example 15: Example of compression of overcoated LP microcapsules according to the invention.

Overcoated particles described in Example 9 are put into the form of tablets to be swallowed with a Korsch alternative press equipped with an oblong punch of 19 x 9.5 mm, by mixing with the excipients described below, then direct compression.

Tablets containing 500 mg of Metformin HC1. TABLE 27

TABLE 28

Figure 6 attached shows the dissolution profile obtained for these overcoated microcapsule tablets.

The test of similarity of the solutions comparing the microcapsules of example 6 and the tablet of example 15 leads to a coefficient £ 2 greater than 50. The dissolution profile is not significantly modified.

Example 16:

Manufacture of LP microcapsules that do not intrinsically have good compressive strength. These particles have a core in the form of a PA granule, hard and brittle.

Aciclovir granules are prepared by wet granulation in a Fielder®PMA 65 granulator. To this end, 11,640 g of fine powder aciclovir are mixed with 360 g of polyvinylpyrrolidone K30, then granules in purified water until obtaining grains. The wet granules are dried in a fluidized air bed and sieved. 4,500 g of these sieved aciclovir granules, with a particle size of between 200 and 500 microns, are film-coated in a fluidized air bed using an ethylcellulose / magic stearatexxm / castor oil / PNP mixture: 73.1 / 9.86 / 7.90 / 7.90, in solution in an acetone / isopropyl alcohol mixture: 60/40.

The coating parameters are as follows: device: Aeromatic® MP2 temperature of the coating solution: ambient temperature fluidization air flow: 200 m3 / h product temperature: 40 ° C spraying pressure: 2 bar air temperature spraying: room temperature flow rate of sprayed solution: 100 g / min

The dissolution profile is as follows:

TABLE 29

Figure 7 attached shows the dissolution profile obtained for the non-overcoated microcapsules.

Example 17:

The LP coated particles of Example 16 are put into the form of orodispersible tablets with a Korsch alternative press equipped with a flat punch with a diameter of 18 mm, by mixing with the excipients described below, then direct compression.

Tablets containing 500 mg of aciclovir TABLE 30

TABLE 31

Figure 7 attached shows the dissolution profile obtained for these tablets of non-overcoated microcapsules.

The test of similarity of the solutions comparing the microcapsules of Example 16 and the tablet of Example 17 leads to a coefficient f2 of less than 50. The dissolution profile is modified.

Example 18: Example of overcoating according to the invention and compression of the overcoated LP microcapsules.

200 g of the LP coated particles described in Example 16 are overcoated by coating in a fluidized air bed with a mixture composed of 25 g of hydrogenated castor oil (Cutina® HR) and 25 g of polyvinylpyrrolidone (Plasdone® K29 -320), dissolved in 300 g of isopropyl alcohol. The coating parameters are identical to those of Example 8. The dissolution profile of the overcoated microcapsules is as follows

TABLE 32

Tablets containing 500 mg of aciclovir.

TABLE 33

TABLE 34

Figure 7 attached shows the dissolution profile obtained for the overcoated microcapsules.

The test of similarity of the solutions comparing the microcapsules of example 16 and the tablet of example 18 leads to a coefficient £ 2 greater than 50. The dissolution profile is not significantly modified.

Claims

1 - Tablet, preferably orodispersible, based on reservoir-type microcapsules, allowing the sustained release in vivo of at least one medicinal and / or nutritional active ingredient (PA), these constituent microcapsules of the tablet being of the type of:

Each formed by a non-deformable core comprising PA and covered by at least one coating film controlling the prolonged in vivo release of PA,

• and having a particle size between 50 and 1000 microns, preferably between 100 and 750 microns, and, more preferably still, between 200 and 500 microns, characterized in that these microcapsules comprise at least one outer envelope of overcoating based on '' at least one deformable organic constituent having a melting temperature between 40 ° C and 120 ° C, preferably between 45 ° C and 100 ° C.

2 - Tablet according to claim 1, characterized in that the external envelope of overcoating of the microcapsules comprises at least 10% by weight of deformable organic constituent.

3 - Tablet according to claim 1, characterized in that the deformable organic component of overcoating of the microcapsules is selected from polyalkylene glycols, polyethylene glycols having a molecular weight of 6000 to 20000 D, being particularly preferred.

4 - Tablet according to claim 1, characterized in that the deformable organic constituent of overcoating of the microcapsules is a fatty substance or mixture of fatty substances.

5 - Tablet according to claim 4, characterized in that the deformable organic constituent of overcoating of the microcapsules is selected from the group of fatty substances comprising: hydrogenated vegetable oils, fatty acids, fatty alcohols, fatty acid esters and / or fatty alcohol, polyolefins and mineral, vegetable, animal or synthetic waxes, esters of fatty acids such as di and triglycerides and their mixtures, glycerol behenate as well as hydrogenated castor oils, soybeans , cotton and palm being particularly preferred. 6 - Tablet according to any one of claims 1 to 5, characterized in that the overcoating comprises:

an inorganic filler such as silica or titanium dioxide for example or organic such as microcrystalline cellulose for example, and / or at least one lubricant such as magnesium stearate or sodium benzoate for example,

* and / or at least one hydrophilic polymer such as water-soluble derivatives of cellulose, synthetic polymers preferably polyvinylpyrrolidone, acrylic and methacrylic derivatives, or polyvinyl alcohols (APN), * and / or at least one surfactant.

7 - Tablet according to any one of claims 1 to 6, characterized in that the external overcoating envelope represents from 5 to 50%, preferably from 10 to 30%, and more preferably still of the order of 20% by dry weight of the total mass of the microcapsules.

8 - Tablet according to any one of claims 1 to 7, characterized in that the coating film of the microcapsules has the following composition:

2 - at least one nitrogenous polymer (P2) present in an amount of 2 to 25, preferably 5 to 15% by dry weight relative to the total mass of the coating composition and consisting of at least one polyacrylamide and / or a poly-Ν-vinylamide and / or a poiy-Νvinyl-lactam, polyacrylamide and / or polyvinylpyrrolidone being particularly preferred;

3 - at least one plasticizer present in an amount of 2 to 20, preferably from 4 to 15% by dry weight relative to the total mass of the coating composition and consisting of at least one of the following compounds: glycerol esters, phthalates, citrates, sebacates, esters of cetyl alcohol, castor oil, salicylic acid and cutin, castor oil being particularly preferred; 4 - at least one surfactant and / or lubricant, present in an amount of 2 to 20, preferably from 4 to 15% by weight on a dry basis relative to the total mass of the coating composition and chosen from surfactants - anionic active ingredients, preferably the alkali or alkaline earth salts of fatty acids, stearic and / or oleic acid being preferred, and / or among nonionic surfactants, preferably polyoxyethylenated sorbitan esters and / or castor oil derivatives polyoxyethylenated, and / or among lubricating agents such as stearates, preferably calcium, magnesium, aluminum or zinc, or such as stearyl fumarate, preferably sodium, and / or glycerol behenate; said agent possibly comprising a single or a mixture of the above products.

9 - Tablet according to any one of claims 1 to 8, characterized in that the composition of the coating film of the microcapsules comprises from 60 to 80% of ethylcellulose, from 5 to 10% of polyvinylpyrrolidone, from 5 to 10 % castor oil and 2 to 8% magnesium stearate.

10 - Tablet according to any one of claims 1 to 9, characterized in that the microcapsules have the following weight composition (% by weight on a dry basis): PA-based particles: from 50 to 80; preferably from 55 to 65, coating film: from 10 to 30; preferably from 15 to 25, overcoating envelope: from 10 to 30; preferably from 15 to 25.

11 - Tablet according to any one of claims 1 to 10, characterized in that the overcoated microcapsules comprise an amount of PA> 50% by weight on a dry basis relative to their total mass.

12 - Tablet according to any one of claims 1 to 11, characterized in that it has a hardness D> 20 N.

13 - Tablet according to any one of claims 1 to 12, characterized in that the PA used belong to at least one of the families of the following active substances: antiulcer, antidiabetic, anticoagulant, antithrombic, lipid-lowering, antiarrhythmic, vasodilators , antianginal, antihypertensive, vasoprotective, fertility promoters, inducers and inhibitors of uterine labor, contraceptives, antibiotics, antifungal, antiviral, anticancer, anti-inflammatory, analgesic, antiepileptic, antiparkinsonian, neuroleptic, hypnotic, anxiolytic, anti-anxiety, psychostimulants, anti-anxiety, anti-anxiety antihistamines or antiallergics. 14 - Tablet according to any one of claims 1 to 13, characterized in that the PA is chosen from the following compounds: pentoxifylline, prazosine, aciclovir, nifedipine, diltiazem, naproxen, ibuprofen, flurbiprofen, ketoprofen, fenoprofen, indomethacin, diclofenac , fentiazac, estradiol valerate, metoprolol, sulpiride, captopril, cimetidine, zidovudine, nicardipme, terfenadine, atenolol, salbutamol, carbamazepine, ranitidine, enalapril, simvastatin, fluoxetine, alprazolam, famotidine, ganciclovirone, ganciclovirone, ganciclovirone perindopril, morphine, pentazocine, paracetamol, aspirin, metformin, omeprazole, metoclopramide and their mixtures.

15 - Tablet according to any one of claims 1 to 14, characterized in that the AP consists of at least one nutritional and / or dietary supplement, preferably chosen from vitamins, amino acids, trace elements, antioxidants and their mixtures.

16 - Microcapsules as defined in any one of claims 1 to 11, 13 to 15.

17 - Use of the microcapsules according to claim 16 for the preparation of pharmaceutical or dietetic forms, preferably in the form of advantageously orodispersible tablets.