WO2005025566A1

WO2005025566A1 - Oral pharmaceutical formulations containing the active ingredient irbesartan

Info

Publication number: WO2005025566A1
Application number: PCT/TR2004/000040
Authority: WO
Inventors: Abdullah Uslu
Original assignee: Nobel Ilac Sanayi Ve Ticaret As
Priority date: 2003-09-18
Filing date: 2004-09-16
Publication date: 2005-03-24
Also published as: EP1670461A1; TR200601092T1; TR200301553A1

Abstract

This innovation deals with the newly developed preparation method of new pharmaceutical dosage forms that contain the active substance irbesartan and that are orally administrated. Owing to the development of this formulation, the dissolution characteristics of irbesartan have been improved.

Description

DESCRIPTION

_{ORAL PHA}RMACEUTICAL FORMULATIONS CONTAINING THE ACTIVE INGREDIENT IRBESARTAN

This innovation is related to pharmaceutical formulations containing the active ingredient named irbesartan. The formulations mentioned in this innovation are the pharmaceutical formulations appropriate for an oral use and preferably presented in tablets or capsules.

10 Irbesartan is a strong and long effective non-peptide tetrazole derivative and an angiotensin II type 1 receptor (ATi) antagonist. Its chemical composition is as follows: 2-butyl-3-[[2'-(lH-tetrazol-5-yl) [1, l'-biρhenyl]-4-yl] methyl] 1, 3 -diazaspiro [4,4] non- l-en-4-one. It is used alone or with other antihypertensive agents to treat high blood

15 pressure. Irbesartan is clinically used alone as once-daily doses of 75 mg, 150 mg or 300 mg or combined with other antihypertensive agents to treat hypertension. Irbesartan is defined under the patent number US5270317 and its molecular structure is as represented below:

20 Irbesartan is a white crystalline powder that is slightly soluble in alcohol and methylene chloride and insoluble in water. Resulting from the high density of the irbesartan powder, factors such as bad fluidity properties and adherence to the surfaces affect negatively this ingredient during the tablet and capsule preparation process. This is why,

25 when a formulation containing the active ingredient irbesartan is prepared, the properties that are inappropriate for the tablet & capsule preparation have to be surmounted by using convenient excipients and adequate production methods. The poor solubility of irbesartan makes the wetting and the disintegrating agents more important within the formulation. Under the specified doses and physico-chemical properties, the preparation of a formulation, which active ingredient's size is easy for the oral administration, necessitates the use of excipients in limited quantities. A product that is prepared in an appropriate pharmaceutical form can lead to the expected therapeutic result. The starting, without delay, of the antihypertensive property has a vital importance for the therapeutic activity of the formulation. For that purpose, the formulation's dissolution properties are determinant. After the oral administration of Irbesartan, as it is the case for some prodrugs, it is not subject to biotransformation. The oral bio-availability of irbesartan is around 60-80%. The peak plasma value of irbesartan is attained 1-1.5 hours after dosing and its terminal elimination half-life averages 11-15 hours. In the hypertension treatment, the daily dosing can be started at 75 mg and raised up to 300 mg till the convenient treatment result is achieved. In small quantities, if necessary, a diuretic such as hydrochlorotiazide can complete the treatment. Hydrochlorotiazide acts like an additive to the pharmacological activity of irbesartan.

The patent number EP0747050 describes the pharmacological compositions that contain the active ingredient irbesartan. In this patent, apart from irbesartan, the formulation includes a diuretic. The team that prepared the invention presented in the patent EP0747050 describes a similar formulation in the patent number US5994348.

The team that prepared the invention presented in the patent US5994348 describes a similar formulation in the patent number US 6342247.

Irbesartan, which is an angiotensin II receptor antagonist, effects as an antihypertensive on the rennin-angiotensin system by selectively blocking the angiotensin II type 1 receptors. In order to reach a quick reaction, the developed antihypertensive drugs have been formulated so to reach minimum 80% of dissolution at 15 minutes after dosing and minimum 90% of dissolution at 30 minutes after dosing. For that purpose the formulation includes tablet or capsule form preparation that contains pharmacologically appropriate excipients. Owing to the excipients added to the formulation, the disintegration and dissolution properties of the tablet or capsule form are situated at the desired levels. In this formulation, the following ingredients are used: - Cellactose 80 and/or spray dried lactose, pre-gelatinized starch as filling material and/or binding agent - Avicel PH 102 as filling material - Ac-di-sol as disintegrant - Poloxamer 188 as surfactant - Aerosil 200 as glidant - Magnesium stearate as lubricant

This formulation was prepared according to the wet granulation method.

Given that irbesartan is not soluble in water, Poloxamer 188 that is a non-ionic surfactant is used in our formulation in order to augment the solubility. The proportion of Poloxamer 188 used in the formulation represents 0.5 - 8% of the tablet's weight, preferably 3%. During the development of the formulation, granulation was done with the water and alcohol solutions of Poloxamer 188. However when instead of water alcohol was used for the granulation, it appeared that irbesartan had a soluble property in alcohol and that thanks to this property better dissolution results were obtained. According to that, during the granulation with the alcoholic Poloxamer solution, a part of the irbesartan was dissolved and this dissolved part recrystallized with the Poloxamer while drying. For that reason, the granulation made with alcohol gives better dissolution values than the one made with water. The filling materials used in our formulation are Cellactose 80 and/or spray dried lactosβi Avicel PH 102 and pre-gelatinized starch.

When formulations of irbesartan were prepared by using lactose monohydrate, the dissolution results being not at the expected level, spray dried lactose, and/or Cellactose 80 were used in replacement to prepare formulations because they are constituted of smaller particle size (Cellactose 80 is made of 75% of spray dried lactose monohydrate and of 25%o of cellulose). In the formulations developed with this innovation, the dissolution values enhanced and the dissolution related results were more convenient because the specific surface area of Cellactose 80 and/or spray dried lactose is wider. Our formulations show that the Cellactose 80 and/or spray dried lactose are more appropriate excipients. Owing to the small size of its particles, spray dried lactose offers a bigger specific surface area. For that purpose, the active ingredient granulized with Cellactose 80 and/or spray dried lactose gave the desired dissolution specificities thanks to the wide surface area that resulted after the disintegration of the tablets or capsules prepared according to this technique. The proportion of Cellactose 80 and/or spray dried lactose used in the formulation represents 5 - 50% of the tablet's weight, preferably

10.25%.

Besides, since Cellactose 80 contains cellulose, the binding properties resulting from it were used. Avicel PH 102 is an appropriate excipient for the direct compression. The disintegrating properties of this ingredient were also used in our formulation. This is why, after the preparation of the granules, they were mixed with Avicel PH 102 and then the tablets were compressed.

The pre-gelatinized starch is used for the tablets prepared with the wet granulation method because of its poor fluidity properties. In the formulation, we also took advantage of the binding characteristics of the pre-gelatinized starch.

In order to ensure a rapid disintegration, the disintegrant added to the formulation is the super disintegrant Ac-Di-Sol.

Aerosil 200 was added to the formulation to reduce the static electricity generated among the powder particles and by doing so it is aimed to improve the fluidity features.

The lubricant used in the formulation is magnesium stearate. Thus, the compression process can be done without the tablets adhering to the tablet punch.

Differently from the known formulations of irbesartan, the present innovation contains

Cellactose 80 and/or spray dried lactose. Besides, in the developed formulation, the granulation was operated with alcohol instead of water and this granulation process leads to more suitable dissolution related values. Reaching higher dissolution values and a quicker dissolution process are two wanted features of the antihypertensive agents of the pharmaceutical formulations. In those conditions, the antihypertensive activity is expected to start earlier and to work more efficiently. Reaching higher dissolution values and a quicker dissolution process are realized through the use of Cellactose 80 and/or spray dried lactose and through the application of the granulation process with alcohol.

In the formulation that is the subject of this innovation, tablets were prepared by using in the same proportion lactose monohydrate instead of Cellactose 80 and/or spray dried lactose and by implementing the granulation with water and alcohol without changing the proportions of the other excipients. When the dissolution profiles are taken into consideration, it can be noted that the formulation, subject of this innovation, leads to the best dissolution profile. The figure 1 presents the compared dissolution profiles of the tablets prepared by using: - Lactose monohydrate and granulation with water (Formula 2- ~*~) - Granulation with alcohol (Formula 1- — o— ) - Cellactose 80 and granulation with alcohol (Formula 3- —*-, this is the subject of our innovation) The figure 2 presents a comparative dissolution graph of the formulation according to the present invention and a product named Karvea (Karvea 300 mg * ; Irbesartan 300 mg -«--- ).

SAMPLES PREPARATION OF THE TABLETS CONTAINING IRBESARTAN

The tablet formulation of the active substance irbesartan according to present invention is available in 3 different dosages. These dosages respectively contain 75mg, 150 mg, and 300mg of the active substance irbesartan. The table 1 presents the weight/weight % (w/w %) values of the active and inactive ingredients included in the formulation. Table 1

The table 2 presents the weight values of the inactive ingredients included in the 75 mg, 150mg and 300mg formulations containing the active ingredient irbesartan. Table 2

The table 3 presents the dissolution rates of the comparison between Karvea (contains irbesartan) and the irbesartan formulation of present invention after 5, 10, 15, 20 and 30 minutes of dissolution. Table 3

Claims

1. This document includes the formulations that are appropriate for an oral administration and that contains the active substance irbesartan, which is an angiotensin II type 1 receptor antagonist.

2. As defined in claim 1, these new oral pharmaceutical formulations contain the active substance irbesartan and are characterized by being a composition including between 50 mg and 900 mg of active ingredient irbesartan, preferably 75 mg, 1 50 mg or 300 mg.

3. As defined in claim 1, these new oral pharmaceutical formulations contain the active substance irbesartan and are characterized by being a composition of surfactant, filling materials, disintegrant, binding and lubricant substances.

4. As stated in claim 3, these new oral pharmaceutical formulations contain the active substance irbesartan and are characterized by being a pharmaceutical composition preferably in tablet or capsule form.

5. As defined in claim 1 and 4, these new oral pharmaceutical formulations are pharmaceutical compositions characterized by containing, in proportion of the tablet weight, between 40 and 60 %, preferably 50 % of irbesartan.

6. As defined in claim 3 and 4, these new oral pharmaceutical formulations include the active substance irbesartan and are characterized by containing surfactant or surfactants that can be anionic, cationic or non-ionic.

7. As defined in claim 6, these new oral pharmaceutical formulations include the active substance irbesartan and are characterized by containing a non-ionic surfactant as surfactant.

8. As defined in claim 7, these new oral pharmaceutical formulations include the active substance irbesartan and are characterized by containing a non-ionic surfactant, which is preferably Poloxamer 188. In the formulation, the quantity of Poloxamer 188 used is in proportion of the tablet weight: between 0.5 and 8 %, preferably 3 %.

9. As defined in claim 3, these new oral pharmaceutical formulations include the active substance irbesartan and are characterized by containing Cellactose 80 and/or spray dried lactose as filling material.

10. As defined in claim 9, these new oral pharmaceutical formulations include the active substance irbesartan and are characterized by containing Cellactose 80 in proportion of the tablet weight, between 5 and 50 %, preferably 10.25 %.

11. As defined in claim 4, these new oral pharmaceutical formulations include the active substance irbesartan and are characterized, during the preparation of the tablet or capsule formulation, by the use of the wet granulation method with alcohol as a wetting agent.

12. As defined in claim 11, these new oral pharmaceutical formulations include the active substance irbesartan and are characterized by the preferable use of 96 % ethyl alcohol during the granulation process.

13. As defined in claim 4, these new oral pharmaceutical formulations include the active substance irbesartan and are characterized by the use of disintegrants, binders, lubricants and glidants in the pharmaceutical formulation to prepare tablet or capsule forms.

14. As defined in claim 1, 3 and 4, these new oral pharmaceutical formulations include the active substance irbesartan and are characterized by the following dissolution values: - Minimum 80 % of dissolution at 15 min after the dosing, preferably superior to 80 %. - Minimum 90 % of dissolution at 30 min after the dosing, preferably superior to 90 %.