NEW GALENIC FORMULATIONS WITH PROGRAMMED RELEASE

Abstract: New galenic formulations with programmed release, to be administered by oral route, containing as the active ingredient a drug selected from the non steroidal antiinflam­ matory, bronchodilator, vasodilator, cardiovascular and muscle relaxant drugs. In these new formulations, a portion of the active ingredient is released in a short time, so that the drug can quickly develop its therapeutic action reaching the necessary hematic levels, while the remaining portion of the active constituent is released in a longer interval of time so as to allow the therapeutic coverage till the subsequent adminis­ tration. Said therapeutic coverage can even last 24 hours; thus the new galenic formulations object of the present invention are suitable for a once a day administration.

Description: The present invention relates to new galenic formulations with programmed release, to be administered by oral route, containing as the active ingredient a drug selected from sodium diclofenac, sodium naproxen and bamifylline hydrochloride. In these new formulations, a portion of the active ingredient is released in a short time, so that the drug can quickly develop its therapeutic action reaching the necessary hematic levels, while the remaining portion of the active constituent is released in a longer interval of time so as to allow the therapeutic coverage till the subsequent administration. Said therapeutic coverage can even last 24 hours; thus the new galenic formulations object of the present invention are suitable for a once a day administration. The art skilled man knows well the problems connected with the repeated administrations of drugs. Apart from the trouble and the discomfort, mostly psychologic, which the patient can experience when he has to recollect of taking that determinate medicine three or four times a day (as it happens, for instance, with paracetamol), it must be borne in mind that, from the point of view of the absorption kinetics, a repeated administration is responsible of very high hematic levels of the drug which repeatedly occur in the organism of the patient, with a remarkable increase in the possibility of side effects. In the literature many methodologies are described, generically called "retard", by means of which the number of administrations of a drug can be reduced while keeping unaltered its therapeutic effectiveness along the time. EP-A-0 255 002 describes new galenic formulations with programmed release, to be administered by oral route containing as the active ingredient a compound endowed with antiphlogistic, analgesic and antipyretic activity like, for instance, an arylacetic or an arylpropionic acid and the pharmaceutically acceptable salts thereof. Patent abstract of Japan vol. 10, No. 203 relates to a sustained release diclofenac pharmaceutical consisting of (A) rapid-acting diclofenac sodium prepared by forming untreated or pulverized diclofenac sodium into granules or fine granules with a usual excipient or binder and (B) slow-acting diclofenac sodium formulated by forming a film of an enteric substance, e.g. methacrylic-acid methyl methacrylate copolymer, or water-insoluble substance, e.g. ethyl cellulose, on the above-mentioned granules or fine granules or kneading the active constituent with an enteric substance or water-insoluble substance at 6:4∼2:8 ratio of the components (A) to (B). US-A-2 793 979 describes a pharmaceutical formulation prepared of time delay and non-time delay granules which are admixed and tabletted. The time delay materials are selected from fatty acids, fatty alcohols and esters. Equal quantities by weight of the granules of the two types are mixed together and tabletted. Slow-release tablets of indomethacin, where the active principle is coated by a film of a hydrophilous polymer and by a cellulose ether, are claimed in Japanese laid open application J 58170712, while in Japanese laid open application J 59084821, diclofenac, which is another well known antiphlogistic agent, is mixed with β-cyclodestrin. In DE-OS-3001797, indoprofen, a good analgesic and antiinflammatory agent which has the drawback of having a short plasmatic half-life, is microencapsulated in a protective layer of a cellulose ether, thus obtaining a remarkable improvement of its plasmatic half-life. Finally, in European publications EP 0094116, EP 0094117 and EP 0094123, granules are described which have a double coating, the first made by polyvinylpyrrolidone and the second one made by acrylic polymers or by cellulose esters or by fatty or oily substances, which should allow a better release of antiphlogistic drugs either in the stomach and in the gut. In all of these galenic formulations, however, the initial release of the active ingredient is gradual and slow, so that the therapeutic effect begins only some hours after the administration. This is an evident drawback, especially in case of drugs which contemporaneously present antiinflammatory, analgesic and antipyretic activity, where often a quick release is needed in order to obtain a prompt analgesic effect, besides the slow and regular release in order to cure the inflammation. Object of the present invention are new galenic formulations with programmed release, immediate and delayed. These formulations are administrable by oral route and contain, as the active principle, a drug selected from sodium diclofenac, sodium naproxen and bamifylline hydrochloride. In order to remove the drawbacks of the known controlled release formulations, and in order to obtain an adequate therapeutic response since the beginning, the galenic formulations object of the present invention are prepared by mixing a granulate having immediate release containing from 15 % to 85 % of the whole amount of the active principle prepared by wet granulating the active principle with suitable adjuvants such as binding, disintegrating and lubricating agents, by drying the granules in an oven at 50°C for 4 hours and by sifting them on a sieve having meshes of 1 mm, together with a granulate having controlled release containing from 15 % to 85 % of the whole amount of the active principle prepared by wet granulating the active principle together with the retarding agents, by drying the granules in an oven at 50°C and by sifting them through a sieve having meshes of 1 mm. In this way, by suitably selecting both the kind and the amount of the agents to be used in the manufacture of the two granulates, and the weight ratio between the two types of granulate, it is possible to obtain pharmaceutic formulations having an immediate therapeutic activity which protracts along 12-24 hours, being therefore suitable for a once a day administration. This effect is due to the particular structure that the joining of the two granulates gives to the galenic preparations. It was really found that the galenic formulations object of the present invention disintegrate in such a manner that they release microgranules some of whom, being made from the immediate release granulate, are quickly adsorbed by the body, while the others, being made from the controlled release granulate, give the active principle in a long period of time when they get in contact with an aqueous medium like, for instance, water itself or acidic aqueous solutions or aqueous solutions which simulate the gastric juices or the gastric juice itself. The great advantage of these galenic formulations in respect of the usual delayed formulations is that, in the present invention, there is no great local concentration of drug as it homogenously disperses into the medium in which it will be adsorbed, because of the disintegration in microgranules of the formulation in which the drug is incorporated. A further object of the invention is therefore represented by the particular kind of galenic support where the active principle can be incorporated. This galenic support is characterized in that it disintegrates in microgranules which are suitable both for the immediate and the delayed release of the active principle which can be incorporated in them. Each of these microgranules has a diameter not greater than one millimetre. In this support, the microgranules suitable for the immediate relase of the active principle are in an amount comprised between 5% and 40% of the total weight of the support, while the microgranules suitable for the delayed release are in an amount comprised between 60% and 95% of the totale weight of the support. In the experimental tests carried out on the formulations object of the present invention, we found that the best therapeutic response was obtained when the active principle was contained in an amount between about 15% and about 85% in weight of the total of the active principle itself, both in the immediate release granulate and in the controlled release granulate. The drugs in carrying out the present invention are sodium salts of naproxen and diclofenac and the bamifylline hydrochloride. Tablets, capsules, sugar coated tablets and granulates for suspension or for solution in suitable liquid media are the preferred galenic formulations. The preparation of the galenic formulations object of the present invention is hereinafter described, being evident for the man skilled in the art that the excipients used in the preparation of the granulates are the same which constitute the galenic support, which is also object of the present invention. In the preparation of the galenic formulations object of the present invention, the immediate release granulate is prepared by wet granulating the active principle with suitable adjuvant agents like binding, disintegrating and lubricating agents, then drying in oven at 50°C for 4 hours the granules and lastly sifting the granules on a sieve having meshes of 1 mm. Polyvinylpyrrolidone, carboxymethylcellulose, microcrystalline cellulose, lactose, saccharose, mannitol, gum-arabic, pectin and gelatin can be advantageously used as binding agents. Starch, sodium starch glycolate, alginates and reticutaled polyvinylpirrolidone can be used as disintegrating agents. Talc, magnesium stearate, stearic acid and silica gel can be used as lubricating agents. Polyvinylpyrrolidone, lactose, maize starch, sodium starch glycolate and magnesium stearate are the preferred adjuvants in the fulfillment of the present invention. The granulate having a controlled release, in its turn, is prepared by wet granulating the active principle together with the retarding agents, drying the granules in oven at 50°C and sifting them through a sieve having meshes of 1 mm. Many retarding agents can be advantageously used; they are preferably selected among ethylcellulose, methylcellulose, polyvinylacetate, metacrylic acid esters, cellulose acetate, fatty alcohols containing from 12 to 32 carbon atoms, glyceric esters of fatty acids containing from 10 to 22 carbon atoms, like the mono- and di-stearate of glycerile, esters of fatty acids and alcohols having from 12 to 31 carbon atoms, paraffin, natural waxy substances like beeswax, unbleached wax, candelilla wax, carnauba wax, sealing wax, spermaceti, ozokerite and hydrogenated vegetable oils like hydrogenated castor oil, hydrogenated peanut oil, hydrogenated cotton seed oil and mixtures thereof. Methylcellulose, ethylcellulose, hydrogenated vegetable oils and mixtures thereof are the retarding agents preferred in the fulfillment of the present invention. The solvents used for the wet granulation are selected from an alcohol containing from 1 to 4 carbon atoms, an aromatic hydrocarbon, a ketone containing from 3 to 6 carbon atoms, an alkyl halide containing from 1 to 4 carbon atoms, mixtures thereof or mixtures thereof with water. Alcohols containing from 1 to 4 carbon atoms and their mixtures with water are the preferred solvents, mostly 95% ethyl alcohol. In the preparation of the desired galenic formulation, carried out according to known techniques, the two granulates are mixed in such weight ratios that the active principle contained in the final galenic formulation belongs to each one of the two granulates for a percent comprised between 15% and 85% of the whole active principle. The granulate having immediate release, contains from 45% to 90% of active principle, from 2% to 20% of binding agents, from 5% to 40% of disintegrating agents and till 1% of a lubricating agent. The granulate having controlled release contains from 40% to 60% of active principle and from 40% to 60% of a retarding agent or of a mixture of retarding agents. Some examples of galenic formulations obtained according to that previously said, are hereinafter described to illustrate the invention; nevertheless such examples are not to be interpreted as a limitation of the invention itself. EXAMPLE 1 Tablets containing 412.5 mg - 550 mg - 775 mg - 1100 mg of sodium naproxen Immediate release granulate 300 Grams of sodium naproxen, 30 g of sodium starch glycolate, 20 g of maize starch, 30 g of polyvinylpyrrolidone, 20 g of lactose and 4 g of magnesium stearate are mixed and wet granulated with 90 ml of 95% ethyl alcohol. The granules are then dried in oven at 50°C for 4 hours and subsequently sifted on a sieve having meshes of 1 mm. Controlled release granulate 800 Grams of sodium naproxen, 480 g of hydrogenated castor oil and 160 g of ethylcellulose are mixed and wet granulated with 500 ml of 95% ethyl alcohol. The granules are dried in oven at 50°C for 4 hours and then sifted on a sieve having meshed of 1 mm. Tablets The two granulates are carefully mixed and the resulting mixture is put into the compressed tablet machine where it is pressed under a 800 kg/cm² pressure, so obtaining tablets having the average weight of 691.5 mg for the dose of 412.5 mg of sodium naproxen, the average weight of 922 mg for the dose of 550 mg of sodium naproxen, the average weight of 1383 mg for the dose of 775 mg of sodium naproxen and the average weight of 1844 mg for the dose of 1100 mg of sodium naproxen. Some of these tablets were submitted to an in vitro test of release of the active principle in water, by using an apparatus according to the standards of the IX Edition of the Italian Official Pharmacopoeia. The data related to the release of the active principle are listed in the table down below. Time of release % of sodium naproxen released 10 minutes 17.7 20 minutes 22.7 30 minutes 30.0 1 hour 37.7 2 hours 53.0 3 hours 66.6 4 hours 82.5 6 hours 95.8 8 hours 100 EXAMPLE 2 Tablets containing 50 mg - 75 mg - 100 mg - 150 mg of sodium diclofenac Immediate release granulate 50 Grams of sodium diclofenac, 10 g of polyvinylpirrolidone, 20 g of sodium starch glycolate, 10 g of lactose and 20 g of maize starch are mixed and wet granulated with 20 ml of 95% ethyl alcohol. The granules are dried in oven at 50°C for 4 hours and then sifted on a sieve having meshes of 1 mm. Controlled release granulate 150 Grams of sodium diclofenac, 120 g of hydrogenated castor oil and 40 g of ethylcellulose are mixed and wet granulated with 90 ml of 95% ethyl alcohol. The granules are dried in oven at 50°C for 4 hours and then sifted on a sieve having meshes of 1 mm. Tablets The two granulates are carefully mixed and the resulting mixture is put into the compressed tablet machine where it is pressed under a 700 kg/cm² pressure, so obtaining tablets having the average weight of 105 mg for the dose of 50 mg of sodium diclofenac, the average weight of 157.5 mg for the dose of 75 mg of sodium diclofenac, the average weight of 210 mg for the dose of 100 mg of sodium diclofenac and the average weight of 315 mg for the dose of 150 mg of sodium diclofenac. Some of these tablets were submitted to an in vitro test of release of the active principle in water as in example 1. The data related to the release of the active principle are listed in the table down below. Time of release % of sodium diclofenac released 10 minutes 18.5 20 minutes 23.0 30 minutes 27.5 1 hour 38.9 2 hours 53.9 3 hours 67.3 4 hours 77.7 6 hours 83.1 8 hours 91.5 EXAMPLE 3 Tablets containing 600 mg - 900 mg - 1200 mg of bamifylline hydrochloride Immediate release granulat e 360 Grams of bamifylline hydrochloride, 20 g of sodium starch glycolate, 6 g of polyvinylpirrolidone, 4 g of lactose, 4 g of maize starch and 4 g of magnesium stearate are mixed and wet granulated with 90 ml of 95% ethyl alcohol. The granules are dried in oven at 50°C for 4 hours and then sifted on a sieve having meshes of 1 mm. Controlled release granulate 840 Grams of bamifylline hydrochloride, 532 g of hydrogenated castor oil and 168 g of ethylcellulose are mixed and wet granulated with 500 ml of 95% ethyl alcohol. The granules are dried in oven at 50°C for 4 hours and then sifted on a sieve having meshed of 1 mm. Tablets The two granulates are carefully mixed and the resulting mixture is put into the compressed tablet machine where it is pressed under a 800 kg/cm² pressure, so obtaining tablets having the average weight of 969 mg for the dose of 600 mg of bamifylline hydrochloride, the average weight of 1453.5 mg for the dose of 900 mg of bamifylline hydrochloride and the average weight of 1983 mg for the dose of 1200 mg of bamifylline hydrochloride. Some of these tablets were submitted to an in vitro test of release of the active principle in water by operating as in example 1. The data related to the release of the active principle are listed in the table down below. Time of release % of bamifylline hydrochloride released 10 minutes 13.3 20 minutes 20.8 30 minutes 21.6 1 hour 37.4 2 hours 50.3 3 hours 61.0 4 hours 68.8 6 hours 83.7 8 hours 91.0 Example 4 Capsules containing 412.5 mg of sodium naproxen 20.2 Grams of immediate release granulate and 40.5 g of controlled release granulate prepared according to the example 1 are carefully mixed and the resulting mixture is used to fill up gelatine capsules each containing 412.5 mg of sodium naproxen. EXAMPLE 5 Sugar coated table ts contai ning 75 mg of sodium diclofenac 5.50 Grams of immediate release granulate and 10.33 g of controlled release granulate prepared according to example 2 are carefully mixed and the resulting mixture is used for the production, according to known techniques, of sugar coated tablets each containing 75 mg of sodium diclofenac. EXAMPLE 6 Granulate for solution or suspension containing 900 mg of bamifylline hydrochloride 39.8 Grams of immediate release granulate and 99 g of controlled release granulate prepared according to example 3 are carefully mixed together with 200 g of orange granulate and the resulting mixture is used to fill up granulate packets each containing 900 mg of bamifylline hydrochloride.

Claims: Claims for the following Contracting States : AT, BE, CH, DE, FR GB, IT, LI, LU, NL, SE Galenic formulations for oral use with programmed release containing as the active principle a drug selected from sodium diclofenac, sodium naproxen and bamifylline hydrochloride, characterized in that they are prepared by mixing a granulate having immediate release containing from 15 % to 85 % of the whole amount of the active principle prepared by wet granulating the active principle with suitable adjuvants such as binding, disintegrating and lubricating agents, by drying the granules in an oven at 50°C for 4 hours and by sifting them on a sieve having meshes of 1 mm, together with a granulate having controlled release containing from 15 % to 85 % of the whole amount of the active principle prepared by wet granulating the active principle together with the retarding agents, by drying the granules in an oven at 50°C and by sifting them through a sieve having meshes of 1 mm. Galenic formulations according to claim 1 wherein the immediate release granulate contains from 45% to 90% of active principle, from 2% to 20% of binding agents, from 5% to 40% of disgregating agents and till 1% of lubricating agents. Galenic formulations according to claims 1 and 2 where the controlled release granulate contains from 40% to 60% of active principle and from 40% to 60% of a retarding agent or of a mixture of retarding agents. Galenic formulations according to each of the previous claims wherein the binding agents are selected from polyvinylpyrrolidone, carboxymethylcellulose, microcrystalline cellulose, lactose, saccharose, mannitol, arabic gum, pectin and gelatin, the disintegrating agents are selected from starchs, alginates, sodium starch glycolate and reticulated polyvinylpyrrolidone, the lubricating agents are selected from magnesium stearate, talc, stearic acid and silica gel and the retarding agents are selected from ethylcellulose, methylcellulose, polyvinylacetate, metacrylic acid esters, cellulose acetate, fatty alcohols containing from 10 to 32 carbon atoms, glyceric esters of fatty acids containing from 10 to 22 carbon atoms, esters of fatty acids and alcohols having from 12 to 31 carbon atoms, paraffin, beeswax, unbleached wax, candelilla wax, carnauba wax, sealing wax, spermaceti, ozokerite, hydrogenated castor oil, hydrogenated peanut oil, hydrogenated cotton seed oil and mixtures thereof. Galenic formulations according to claim 4, characterized in that the binding agents are lactose and polyvinylpyrrolidone, the disintegrating agents are maize starch and sodium starch glycolate, the lubricating agent is magnesium stearate and the retarding agents are ethylcellulose and hydrogenated castor oil. Galenic formulations according to each of the preceding claims characterized in that they are selected from tablets, sugar coated tablets, capsules and granulates for solution or suspension. Galenic formulations according to each of the preceding claims characterized in that they disintegrate in microgranules having a diameter not greater than one millimetre. Claims for the following Contracting States : ES, GR Process for the production of galenic formulations for oral use with programmed release containing as the active principle a drug selected from sodium diclofenac, sodium naproxen and bamifylline hydrochloride, characterized by mixing a granulate having immediate release containing from 15 % to 85 % of the whole amount of the active principle prepared by wet granulating the active principle with suitable adjuvants such as binding, disintegrating and lubricating agents, by drying the granules in an oven at 50°C for 4 hours and by sifting them on a sieve having meshes of 1 mm, together with a granulate having controlled release containing from 15 % to 85 % of the whole amount of the active principle prepared by wet granulating the active principle together with the retarding agents, by drying the granules in an oven at 50°C and by sifting them through a sieve having meshes of 1 mm. Process according to claim 1 wherein the immediate release granulate contains from 45% to 90% of active principle, from 2% to 20% of binding agents, from 5% to 40% of disgregating agents and till 1% of lubricating agents. Process according to claims 1 to 2 where the controlled release granulate contains from 40% to 60% of active principle and from 40% to 60% of a retarding agent or of a mixture of retarding agents. Process according to each of the previous claims wherein the binding agents are selected from polyvinylpyrrolidone, carboxymethylcellulose, microcrystalline cellulose, lactose, saccarose, mannitol, arabic gum, pectin and gelatin, the disintegrating agents are selected from starchs, alginates, sodium starch glycolate and reticulated polyvinylpyrrolidone, the lubricating agents are selected from magnesium stearate, talc, stearic acid and silica gel and the retarding agents are selected from ethylcellulose, methylcellulose, polyvinylacetate, metacrylic acid esters, cellulose acetate, fatty alcohols containing from 10 to 32 carbon atoms, glyceric esters of fatty acids containing from 10 to 22 carbon atoms, esters of fatty acids and alcohols having from 12 to 31 carbon atoms, paraffin, beeswax, unbleached wax, candelilla wax, carnauba wax, sealing wax, spermaceti, ozokerite, hydrogenated castor oil, hydrogenated peanut oil, hydrogenated cotton seed oil and mixtures thereof. Process according to claim 4, characterized in that the binding agents are lactose and polyvinylpyrrolidone, the disintegrating agents are maize starch and sodium starch glycolate, the lubricating agent is magnesium stearate and the retarding agents are ethylcellulose and hydrogenated castor oil. Process according to each of the preceding claims characterized in that they are selected from tablets, sugar coated tablets, capsules and granulates for solution or suspension.

Inventors: MARCHI, EGIDIO, ROTINI, LEONE GABRIELE
Applicants: ALFA WASSERMANN S.P.A.
Application year: 1988
Main classification: A61K9
IPC codes: A61K9, A61K31