HK1115315B - Tablet containing hardly soluble active ingredient - Google Patents

Description

Technical Field

The present invention relates to a tablet, particularly a tablet containing a hardly soluble active ingredient.

Background Art

In a tablet containing a hardly soluble active ingredient, a variation arises in dissolution behavior of an active ingredient in some cases. Since this variation is associated with a variation in absorption of the active ingredient, the range of the variation reaching to a certain level or more may result in a variation in efficacy of a medicament as well. In addition, even when there is not such a substantial problem, it is more desirable that there is no variation in quality in products, if at all possible. This is not limited to a medicament, but is also true in all products.

It is known from document JP11-322584 a pharmaceutical preparation containing (A) bezafibrate and (B) an HPC having about 1 to about 5cP viscosity of 2% aqueous solution at 20°C. It is also known from document EP 1 334 732 a stabilized preparation which comprises a drug unstable in preparation containing polyethylene glycol and a coating agent comprising a copolyvidone instead of polyethylene glycol with which the drug is coated.

Disclosure of the Invention Problems to be solved by the invention

The present inventors intensively studied and, as a result, found out that a viscosity of a binder generally used in a tablet is associated with a variation in dissolution behavior of an active ingredient, and further studied, resulting in completion of the present invention.

Means to solve the problems

The present invention provides:

• a tablet containing from about 3 to about 50% weight (w/w) of a hardly soluble active ingredient based on the whole tablet, magnesium stearate, and hydroxypropylcellulose having a viscosity as measured using a 2 % aqueous solution type B viscometer at 20°C, of about 1 to about 4 mPa·s, as a binder
• the hardly soluble active ingredient being (S) -N-[2-(1, 6, 7, 8-tetrahydro-2H-indeno[5,4-b]furan-8-yl)ethyl]propionamide,

Effect of the Invention

According to the present invention, a tablet showing regulated variation in dissolution of a hardly soluble active ingredient is provided.

Brief description of the drawings

• Fig. 1 is a graph showing dissolution behavior of a preparation of Comparative Example.
• Fig. 2 is a graph showing dissolution behavior of a preparation of Example.

Best Mode for Carrying Out the Invention

In the present invention, the term "hardly soluble" means that an active ingredient is hardly soluble in an aqueous solvent such as a body fluid and the like. When the active ingredient is not hardly soluble, originally, a variation in dissolution behavior of the active ingredient is extremely small. Therefore, the present invention is preferably applied to a hardly soluble active ingredient. In the present description, "hardly soluble" specifically means that solubility in water at 20°C is about 1 g/l or less. The present invention is more preferably applied to the active ingredient having solubility in water (20°C) of about 0.7 g/L or less, still more preferably 0.5 g/L or less. An upper limit of a degree of hardly solubility (i.e. lower limit of solubility) is not particularly limited, but the present invention is usually applied to the active ingredient having solubility in water (20°C) of about 0.005 g/L or more.

The hardly soluble active ingredient herein is a hardly soluble compound represented by the formula (I): [wherein R¹ represents a hydrocarbon group optionally having a substituent, an amino group optionally having a substituent or a heterocyclic group optionally having a substituent, R² represents a hydrogen atom or a hydrocarbon group optionally having a substituent, R³ represents a hydrogen atom, a hydrocarbon group optionally having a substituent or a heterocyclic group optionally having a substituent, X represents CHR⁴, NR⁴, O or S (R⁴ represents a hydrogen atom or a hydrocarbon group optionally having a substituent), Y represents C, CH or N, ···· represents a single bond or a double bond, an A ring represents a 5- to 7-membered oxygen atom-containing heterocycle optionally having a substituent, a B ring represents a benzene ring optionally having a substituent, and m represents an integer of 1 to 4] or a salt thereof (hereinafter, simply referred to as a compound of formula (I) in some cases).

The compound (I) is (S)-N-[2-(1,6,7,8-tetrahydro-2H-indeno[5,4-b]furan-8-yl)ethyl]propionamide (general name: Ramelteon) (hereinafter referred to as Compound A in some cases).

The compound (I) is the known compound useful as an agent for preventing or treating sleep disorder, described in JP-A-10-287665 , and can be produced according to the known methods such as the method described in the publication or the like. Document EP 885 210 discloses the synthesis of Ramelteon.

The tablet of the present invention contains about 3 % to about 50% by weight (w/w) of hardly soluble active compound (I) based on the whole tablet. When a content of the hardly soluble active ingredient is less than this amount, originally, a variation in dissolution behavior of the active ingredient is extremely small in the tablet. The tablet of the present invention contains such a hardly soluble active ingredient in an amount of preferably about 5% by weight (w/w) or more, more preferably about 7% by weight (w/w) or more, particularly preferably about 10% by weight (w/w) or more. In addition, a content of the hardly soluble active ingredient in the tablet of the present invention is usually not more than about 50% by weight (w/w).

The tablet of the present invention contains magnesium stearate. Magnesium stearate is a general-use lubricant, and is available as a commercial product. Such a commercially available product of magnesium stearate usually contains components other than magnesium stearate. In the present invention, from a viewpoint of regulated variation in dissolution of an active ingredient and improvement in a rate of the dissolution, magnesium stearate in which the proportion of stearic acid in a fatty acid fraction (the stearic acid content ratio) values about 90% or more is suitably used. The stearic acid content ratio is calculated according to the method described in the Japanese Pharmacopoeia, 14the Edition. The tablet of the present invention preferably contains magnesium stearate in an amount of about 0.7% by weight (w/w) or more based on the whole tablet. The upper limit of the magnesium stearate content is not particularly limited, but usually is not more than about 2% by weight (w/w) based on the whole tablet.

The tablet of the present invention contains hydroxylpropylcellulose having a viscosity of about 1 to about 4 mPa·s (preferably viscosity of about 2 to about 3.4 mPa·s). Hydroxpropylcellulose is a general-use binder, and usually, when it is used as a binder for the tablet, hydroxypropylcellulose having a higher viscosity is used. The present invention is characterized in that hydroxypropylcellulose having a relatively low viscosity is used.

Such hydroxypropylcellulose is available, for example, as a commercially available product (e.g. SSL type, SL type, Nippon Soda Co., Ltd.).

Inter alia, hydroxypropylcellulose having a low mineral obtained by repetition of purification is preferred, and hydroxypropylcellulose having a residue on ignition of not more than about 0.2% as measured after ignition at 600±50°C is preferred. Further, hydroxypropylcellulose which is soluble in water and a polar organic solvent such as an alcohol at normal temperature and has greater solubility in water is preferred.

In the present specification, a numerical value of a viscosity is a numerical value of a viscosity as measured using a 2% Aqueous Solution Type B Viscometer at 20°C.

The tablet of the present invention preferably contains about 3% by weight (w/w) of such a hydroxypropylcellulose based on the whole tablet.

The tablet of the present invention may optionally contain other active ingredients, and other components such as other additives.

The tablet of the present invention can be produced by mixing the hardly soluble active ingredient, magnesium stearate, and hydoxypropylcellulose having a viscosity of about 1 to about 4 mPa·s as well as other optionally incorporated components at a predetermined ratio, and compressing the mixture to tablets according to a normal method which is used for preparation.

More specifically, the tablet can be produced, for example, by the following method.

After a hardly soluble active ingredient and optionally incorporated components (excipient, etc.) are homogeneously mixed in a fluidized bed granulation dryer, the mixture is sprayed with an aqueous solution in which hydroxypropylcellulose having a viscosity of about 1 to about 4 mPa·s is dissolved to granulate in the dryer, and then, dried in the same dryer.

The resultant granules are ground to obtain a particle size-adjusted powder.

Magnesium stearate and optionally incorporated components (disintegrating agent, etc.) are added to the particle size-adjusted powder, and mixed to obtain granules for making tablet.

The granules are compressed into a tablet on a tablet press to obtain an uncoated tablet.

The resultant uncoated tablet is sprayed with a film coating solution in a film coating device to obtain a film coated tablet.

According to the present invention, since an dissolution rate of a hardly soluble active ingredient is improved, and the dissolution rate is converged to an approximate defined value, the tablet of the present invention has a regulated dissolution variation of a hardly soluble active ingredient. In the present specification, the regulated dissolution variation means that a similarity factor (f2 function) which is an index for assessing equality of dissolution behavior between preparations with the same formulation in arbitrarily selected different 2 lots is 50 to 100. The similarity factor (f2 function) is preferably 70 to 100.

The same formulation means that names and amounts of components to be incorporated are substantially the same, and lots of components to be incorporated may be the same or different.

The similarity factor is expressed by the following equation. $f2=50\log \left({\left(1,+,\left(1,/,n\right),\sum _{t=1}^n,{\left(\mathrm{At},-,\mathrm{Bt}\right)}^2\right)}^{-0.5},\times ,100\right)$ wherein At and Bt are average dissolution rates of a test preparation A and a test preparation B, respectively, at each dissolution comparison time point, n is the number of the time points at which an average dissolution rate is compared, and is not less than 6, the test preparation A and the test preparation B are preparations with the same formulation in arbitrarily selected different 2 lots, the dissolution comparison time points are set as follows:

1. (1) when average 85% or more of a hardly soluble active ingredient in the test preparation A is eluted in 15 to 30 minutes: 15, 30, 45 minutes,
2. (2) when average 85% or more of a hardly soluble active ingredient in the test preparation A is eluted after 30 minutes or more but in a defined test time:
   • Ta/4, 2Ta/4, 3Ta/4, Ta, wherein Ta represents a suitable time point at which the average dissolution rate of the test preparation A attains about 85%,
3. (3) when average 85% or more of a hardly soluble active ingredient in the test preparation A is not eluted in a defined test time:
   • Ta/4, 2Ta/4, 3Ta/4, Ta, wherein Ta represents a suitable time point at which an average dissolution rate attains about 85% of an average dissolution rate of the test preparation A in a defined test time.

The tablet of the present invention can be orally administered according to the usual tablet administration regimen.

Specifically, for example, 4 to 16 mg of a hardly soluble active ingredient can be orally administered once a day before going to bed.

Examples

The represent invention will be described in more detail by the following Reference Examples and Examples, but the present invention is not limited thereto.

In the following Examples, as hydorxypropylcellulose (viscosity of 2 to 3.4 mPa·s), 1 to 2 g of hydroxypropylcellulose that is precisely weighted, and has a residue on ignition of not more than 0.2% as measured after ignition at 600±50°C was used.

In the following Examples and Comparative Examples, as a preparation additive, products which meet the Japanese Pharmacopoeia, 14th Edition or the Pharmaceutical Excipients Standards 2003 were used, provided that among preparation additives, as magnesium stearate, products which meet the Japanese Pharmacopoeia, 14th Edition is used in the same manner as other preparation additives, and particularly, magnesium stearate having a stearic acid content ratio of about 90% or more (TAIHEI CHEMICAL INDUSTRIAL CO., LTD.) was used.

Reference Example 1

After Compound A, lactose and corn starch were homogeneously mixed in a fluidized bed granulation dryer according to the formulation in Table 1, the mixture was sprayed with an aqueous solution in which hydroxypropylcellulose had been dissolved to granulate in the dryer, and then, dried in the same dryer. The resultant granules were ground with a 1.5 mmφ punching screen using a power mill to obtain a particle size-adjusted powder. Corn starch and magnesium stearate were added to the particle size-adjusted powder, and mixed in a tumbler mixer to obtain granules for making tablet. The granules were compressed into a tablet weighing 130 mg on a tablet press using a 7.0 mmφ mallet to obtain an uncoated tablet. The resulting uncoated tablet was sprayed with a solution of titanium oxide, hydroxypropylmethylcellulose 2910 in which yellow iron sesquioxide had been dispersed, and copolyvidone in a film coating device to obtain each about 270000 film coated tablets containing 4 mg or 8 mg of Compound A per tablet. Table 1

	4 mg	8 mg
Uncoated tablet
Compound A	4.0	8.0
Lactose	101.6	97.6
Corn starch	19.4	19.4
Hydroxypropylcellulose (viscosity 6 to 10 mPa·s)	4.0	4.0
Magnesium stearate	1.0	1.0
Film coating
Hydoxypropylmethylcellulose 2910	3.75	3.74
Copolyvidone	0.75	0.75
Titanium oxide	0.5	0.5
Yellow iron oxide	-	0.01
Total	135.0	135.0

Example 1

After Compound A, lactose and corn starch were homogeneously mixed in a fluidized bed granulation dryer according to the formulation of Table 2, the mixture was sprayed with an aqueous solution in which hydroxypropylcellulose had been dissolved to granulate in the dryer, and then, dried in the same dryer. The resultant granules were ground with a 1.5 mmφ punching screen using a power mill to obtain a particle size-adjusted powder. Corn starch and magnesium stearate were added to this size-adjusted powder, and mixed in a tumbler mixer to obtain granules for making tablet. The granules were compressed into a tablet weighing 130 mg on a tablet press using a 7.0 mmφ mallet to obtain a uncoated tablet. The resulting uncoated plain tablet was sprayed with a solution of titanium oxide, hydroxypropylmethylcellulose 2910 in which yellow iron oxide or red iron oxide had been dispersed, and copolyvidone in a film coating device to obtain film coated tablets of Preparation A (Comparative Example) and Preparation B (Example) containing 16 mg of Compound A per tablet. The procedure was repeated three times to obtain each 3 lots of preparations (Preparation A: Lot No. Z515A01, Lot No. Z515A02, Lot No. Z515A03) (Preparation B: Lot No. Z515G01, Lot No. Z515G02, Lot No. Z515G03). Table 2

	Preparation A (Comparative Example)	Preparation B (Example)
Uncoated tablet
Compound A	16.0	16.0
Lactose	89.6	89.6
Corn starch	19.4	19.4
Hydroxypropylcellulose (viscosity 6 to 10 mPa·s)	4.0
Hydroxypropylcellulose (viscosity 2 to 3.4 mPa·s)	4.0
Magnesium stearate	1.0	1.0
Film coating
Hydroxypropylmethylcellulose 2910	3.74	3.74
Copolyvidone	0.75	0.75
Titanium oxide	0.5	0.5
Yellow iron sesquioxide	0.01	-
Iron sesquioxide	-	0.01
Total	135.0	135.0

Test Example 1

According to the paddle method in the Japanese Pharmacopoeia (50 rpm, 37°C, 900 mL of water, n=6), the dissolution behavior of Compound A in each 3 lots of Preparation A (Comparative Example) and Preparation B (Example) was measured. Results are shown in Fig. 1 and Fig. 2. In addition, Table 3 and Table 4 show results of calculation of each similarity factor. Table 3

Similarity factor of Preparation A
Comparison of Z515A01 and Z515A02	43
Comparison of Z515A01 and Z515A03	29
Comparison of Z515A02 and Z515A03	45

Table 4

Similarity factor of Preparation B
Comparison of Z515G01 and Z515G02	81
Comparison of Z515G01 and Z515G03	98
Comparison of Z515G02 and Z515G03	85

Industrial Applicability

According to the present invention, a tablet showing regulated variation in dissolution of a hardly soluble active ingredient is obtained.

Claims (1)

1. A tablet containing about 3 to about 50% by weight (w/w) of (S)-N-[2-(1,6,7,8-tetrahydro-2H-indeno[5,4-b]furan-8-yl)ethyl]propionamide based on the whole tablet, magnesium stearate, and hydroxypropylcellulose having a viscosity as measured using a 2% Aqueous Solution Type B Viscometer at 20°C of about 1 to about 4 mPa·s, as a binder.