Patent Description:
In the field of pharmacy, a plurality of medicines has been developed into sustained-release and multi-stage release controlled-release preparations to achieve the purposes of stabilizing blood concentration, reducing medication times, increasing the medication compliance of patients, improving medication safety and curative effect, and reducing side effects and the like. High-activity drugs are used in the clinic with a low dose, showing good therapeutic effects, but sometimes also bring toxic or side effects due to the level and fluctuation of the blood concentration. Therefore, a large proportion of low-dose high-activity drugs need to be developed into sustained-release and controlled-release preparations. At present, the most mature oral sustained-release technologies comprise skeleton sustained-release, membrane-controlled sustained-release and osmotic pump controlled-release, and the like, but these technologies are still difficult to meet the development of sustained-release preparations for some insoluble drugs, and the main problems mainly comprise complicated process preparation and high cost, and further comprise poor control of release speed and degree, insufficient release, and other aspects.

In Oral Controlled Release Formulation Design and Drug Delivery (Hong Wen), it is mentioned that food takes about <NUM> hours to <NUM> hours from mouth to cecum, in which a stomach pH is about <NUM> to <NUM>, a duodenum pH is about <NUM> to <NUM>, and the transit will last for <NUM> hours to <NUM> hours in a colon stage, while the average pH of the colon is about <NUM>. The colon has a relatively high pH value and a long residence time, which provides an important window for drug absorption.

The combination of slow release and targeted release technologies can achieve sustained drug release. <CIT> discloses a sustained-release preparation for an insoluble drug formed by the combination of a matrix sustained-release tablet I and a coated targeted-release tablet II. This combination needs to prepare the two tablets separately, and the combination is realized by filling capsules, which leads to high complexity in the industrialization of the preparation. <CIT> provides a controlled-release gastric retention system, which can achieve a large degree of retention in the stomach to form a sustained-release effect through different combinations, and provides more solutions for the sustained-release development of insoluble drugs.

Common colon targeting technologies comprise coating and skeleton of enteric materials, wherein preparing microspheres or granules from the enteric materials and drugs by solvent evaporation and hot melt extrusion is a common preparation method of an enteric material skeleton.

<NPL> that Eudradit®S <NUM>, ethyl cellulose, and medicaments were formulated into a methanol solution and then dispersed in paraffin, then emulsifier span® <NUM> was used to form tiny microspheres, which were then eluted and dried to obtain prednisolone microsphere preparation, which could position the colon and administer prednisolone.

<NPL> that Eudragit® S100 and Eudragit® L100 were combined with a certain amount of release modifiers Polyox™ WSR <NUM> and Eudragit® L100-<NUM> to make a sustained-release formulation of metoprolol succinate by using the hot melt extrusion (HME) technology.

It is a preferable prescription process to prepare sustained-release or targeted release preparation by enteric materials and bulk drugs, or further adding other release-adjusting materials. However, the preparation process of skeleton microspheres by solvent evaporation is complicated, the preparation conditions are harsh, and the quality controllability is poor. Hot melt extrusion granulation requires special equipment for hot melt extrusion, and the production efficiency of this process is low, which is not conducive to large-scale industrialization.

<CIT> discloses a pharmaceutical composition containing etoposide, which comprises: using an enteric material as a solid dispersion carrier, dissolving and dispersing active pharmaceutical ingredients (API) in the carrier with an organic solvent, drying and pulverizing, and then mixing the solid dispersion with a skeleton type sustained (controlled)-release material, granulating, tableting, and enteric-coating to obtain a sustained-release preparation. However, the content of the method described in this patent is suitable for compounds with high solubility similar to etoposide. A large part of insoluble drugs need to be dissolved by using a large number of organic solvents, and the subsequent drying will also bring the problem of too long preparation time. Moreover, the preparation method of the solid dispersion is difficult in industrialization and low in efficiency.

Some patients who take drugs for chronic diseases and tumors, such as low-dose immunomodulators comprising apremilast, lenalidomide and tofacitinib, and anticoagulants such as apixaban, or the like, take drugs for a long time and may take the drugs many times a day. The sustained-release preparations will help control the blood concentration, reduce side effects and reduce the number of daily doses. Therefore, it is necessary to develop an oral sustained-release composition suitable for low-dose insoluble drugs and a preparation method thereof.

In the research process, the inventor finds that the problems of too fast dissolution or incomplete final dissolution are easy to occur by adopting the physical mixing of the insoluble drug and the sustained-release material or further granulating and then tableting, and a satisfactory development and prescription process of the sustained-release preparation cannot be obtained. The inventor subsequently finds that preparing a suspension by using an enteric material and a slightly soluble compound with small particle size can effectively disperse the API, which not only can effectively control the dissolution rate of the drug in a low pH value solution, but also can fully dissolve the drug in a high pH value solution, and this property can be well used for developing the sustained-release preparation for the insoluble drugs.

Object of the invention: the present invention provides an oral sustained-release composition for a low-dose insoluble drug and a preparation method thereof as set out in the appended claims. release granules containing an enteric material can be quickly prepared by spraying a drug-containing suspension onto a strong liquid sorbent, to improve drug content uniformity. The preparation process uses less solvent and has high production efficiency. Combined with a hydrophilic gel skeleton material, multiple sustained-release effects are formed, and a continuous sustained-release effect is achieved.

Technical solutions: the oral sustained-release composition provided by the present invention consists of a sustained-release granule part and a gel skeleton part, wherein the gel skeleton wraps the sustained-release granules to form a dual sustained-release system, wherein the sustained-release granules contain the insoluble drug, an enteric material and a strong liquid sorbent, and the gel skeleton part contains a hydrophilic gel skeleton material. The sustained-release granules are obtained by preparing the insoluble drug and a liquid substance containing the enteric material into a drug-containing suspension and then spraying the suspension onto the strong liquid sorbent.

The insoluble drug in the oral sustained-release composition according to the present invention accounts for <NUM>%-<NUM>% of a weight of the sustained-release granules, a weight ratio of the insoluble drug to the enteric material is <NUM>: <NUM> to <NUM>: <NUM>, and the strong liquid sorbent accounts for <NUM>%-<NUM>% of the weight of the sustained-release granules; the sustained-release granules account for <NUM>%-<NUM>% of a weight of the oral sustained-release composition; and a dose of the hydrophilic gel skeleton material account for <NUM>%-<NUM>% of the weight of the oral sustained-release composition.

The insoluble drug according to the present invention is present in the oral sustained-release composition at a weight ratio of less than <NUM>%.

The low-dose insoluble drug according to the present invention comprises apremilast, lenalidomide, tofacitinib and apixaban.

d90 in particle size distribution of the insoluble drug is controlled to be less than <NUM> microns; preferably, the d90 is less than <NUM> microns; and most preferably, the d90 is less than <NUM> microns. The smaller the particle size of the insoluble drug is, the easier the insoluble drug is to be wrapped by the enteric material to form sustained-release, and the more conducive to the later dissolution.

The enteric material according to the present invention refers to a polymer material soluble in a pH range of <NUM>-<NUM>, which can ensure that the drug coated by the enteric material is capable of being completely released in the colon. The enteric material comprises any one of a copolymer of methacrylic acid and methyl methacrylate (a molar ratio scope of the methacrylic acid to the methyl methacrylate is <NUM>: <NUM> to <NUM>: <NUM>), and a copolymer of methacrylic acid, methyl acrylate and methyl methacrylate (<NUM>: <NUM>: <NUM>); the frequently-used enteric material comprises a copolymer of methacrylic acid and methyl methacrylate (<NUM>: <NUM>), a copolymer of methacrylic acid and methyl methacrylate (<NUM>: <NUM>), and the copolymer of methacrylic acid, methyl acrylate and methyl methacrylate (<NUM>: <NUM>: <NUM>); and preferably the copolymer of methacrylic acid and methyl methacrylate (<NUM>: <NUM>), and the copolymer of methacrylic acid, methyl acrylate, and methyl methacrylate. In commercial enteric material products, the copolymer of methacrylic acid and methyl methacrylate (<NUM>:<NUM>) refers to acrylic resin <NUM>#, Eudragit L100, or the like; the copolymer of methacrylic acid and methyl methacrylate (<NUM>: <NUM>) refers to acrylic resin <NUM>#, Eudragit S100 or the like; and the copolymer of methacrylic acid, methyl acrylate and methyl methacrylate (<NUM>: <NUM>: <NUM>) refers to Eudragit FS 30D, or the like. The enteric material in the sustained-release granules according to the present invention is added in a liquid form. The liquid substance containing the enteric material is an aqueous dispersion form or an organic solvent solution form. The aqueous dispersion of the enteric material may be self-prepared, and commercial products are also available. Some embodiments comprise commercial products such as Utrecht FS 30D, or the like. The organic solvent solution of the enteric material is obtained by dissolving the enteric material with an organic solvent.

In addition to the enteric material and water, it is necessary to add an alkaline substance during the process of preparing the aqueous dispersion of the enteric material. The alkaline substance comprises aqueous ammonia, sodium hydroxide and potassium hydroxide. The organic solvent solution of the enteric material may be obtained by dissolving the enteric material with acetone, ethanol, carbon tetrachloride and isopropanol.

Before use, the liquid substance of the enteric material may also be added with anti-sticking agent, plasticizer, surfactant, and the like. The anti-sticking agent comprises colloidal silicon dioxide, talcum powder and glyceryl monostearate (GMS); the plasticizing agent comprises glyceryl monostearate (GMS), triethyl citrate (TEC) and polyethylene glycol; and the surfactant comprises sorbitan fatty acid (Span), polysorbate (Tween) and sodium dodecyl sulfate.

The insoluble drug in the present invention may be dispersed into the liquid substance containing the enteric material by stirring, high-shear homogenizing, high-speed vortex, ultrasonic dispersion and other ways to obtain the drug-containing suspension, or the insoluble drug may be mixed and dispersed with a solvent in advance and then added into the liquid substance containing the enteric material for uniform mixing to obtain the drug-containing suspension.

A solid content in the drug-containing suspension is <NUM>-<NUM>%, and preferably <NUM>-<NUM>%.

The strong liquid sorbent in the present invention is a substance that is insoluble in water but has a large adsorbing capacity, which can meet the requirement of timely adsorbing excess solvent in the rapid spraying process of the drug-containing suspension, and reduce the phenomena of fast and excessive granule growth and uneven granulation caused by excessive humidity, so as to quickly and smoothly realize the process of granulating the enteric material liquid into the sustained-release granules.

The strong liquid sorbent comprises microcrystalline cellulose, croscarmellose sodium, croscarmellose, polyvinylpolypyrrolidone, sodium carboxymethyl starch, low substituted hydroxypropyl cellulose, starch and pregelatinized starch, and preferably microcrystalline cellulose, croscarmellose sodium, polyvinylpolypyrrolidone, sodium carboxymethyl starch and low substituted hydroxypropyl cellulose.

The sustained-release granules according to the present invention may also be added with <NUM>-<NUM>% of an adhesive by weight of the sustained-release granules, so as to obtain the sustained-release granules with better granulation effect. The adhesive comprises any one or several of polyvinylpyrrolidone, hydroxypropyl methylcellulose, hydroxypropyl cellulose, carboxymethyl cellulose, carrageenin, alginic acid, arabic gum, pectin, xanthan gum and tragacanth.

Before use, the liquid substance containing the enteric material may be optionally added with any one or a combination of several of <NUM>-<NUM>% of anti-sticking agent, <NUM>-<NUM>% of plasticizer and <NUM>-<NUM>% of surfactant by weight of the sustained-release granules before use, wherein the anti-sticking agent is selected from colloidal silicon dioxide, talcum powder and glyceryl monostearate; the plasticizer is selected from glyceryl monostearate, triethyl citrate and polyethylene glycol; and the surfactant is selected from sorbitan fatty acid, polysorbate, and sodium dodecyl sulfate.

The sustained-release granules according to the present invention may be added into components of the gel skeleton part for granulation together, or the gel skeleton part may also be granulated separately, and then mixed with the prepared sustained-release granules, or the sustained-release granules may be directly mixed with the components of the gel skeleton part.

The oral sustained-release composition according to the present invention, wherein the gel skeleton part contains the hydrophilic gel skeleton material, and may also contain other pharmaceutical adjuvants, comprising a filler, an adhesive, a glidant and a lubricant.

The hydrophilic gel skeleton material comprises arabic gum, tragacanth gum, polyvinyl pyrrolidone (PVP or polyvidone), hydroxypropyl methyl cellulose (HPMC), shellac, hydroxypropyl cellulose (HPC), hydroxethyl cellulose (HEC), alginate, methylated cellulose (MC), carrageenin, carboxymethyl cellulose and sodium salt, carbomer, and polyvinyl alcohol (PVA), and the like.

The hydrophilic gel material in the present invention can realize rapid hydration to form a gel coat, and achieve the purpose of controlling a dissolution rate in an early stage. By adjusting the category and dose of the hydrophilic gel skeleton, a tablet can be corroded in a certain time, and the sustained-release granule part may leave the tablet in the corrosion process, forming an independent sustained-release unit.

A dose of the hydrophilic gel skeleton material in the present invention accounts for <NUM>%-<NUM>% of the weight of the preparation, and preferably, <NUM>%-<NUM>%. When the dose of the hydrophilic gel skeleton material exceeds about <NUM>%, a change range of the sustained-release effect thereof decreases significantly, but the material cost increases.

The gel skeleton part may be optionally added with a filler, an adhesive, a lubricant and a glidant.

The filler in the gel skeleton part according to the present invention comprises, but is not limited to any one or two of cellulose derivatives and starch derivatives, such as comprising lactose, mannitol, xylitol, fructose, sucrose, dextrin, microcrystalline cellulose, pregelatinized starch, sodium carboxymethyl starch, methylated cellulose, hydroxypropyl starch, and the like; and more preferably one or more of lactose, mannitol, dextrin, microcrystalline cellulose and pregelatinized starch. The dose of the hydrophilic gel skeleton material in the present invention accounts for <NUM>%-<NUM>% of the weight of the preparation.

A main function of the filler is to improve compressibility, fluidity, granule formation and other effects. The dose of the filler may be adjusted according to the needs of a target product, and plays a certain auxiliary role.

The adhesive comprises, but is not limited to polyvinylpyrrolidone, starch slurry, hydroxypropyl methylcellulose, hydroxypropyl cellulose, carboxymethyl cellulose, dextrin, carrageenin, alginic acid, arabic gum, pectin, xanthan gum and tragacanth. The main function of the adhesive is to quickly granulate and improve compressibility. A dose of the adhesive in the present invention accounts for <NUM>%-<NUM>% of the total weight of the oral sustained-release composition.

The lubricant comprises, but is not limited to magnesium stearate, calcium stearate, sodium stearate, stearic acid, sodium stearyl fumarate, talcum powder, glyceryl behenate, hydrogenated vegetable oil and stearyl alcohol. A dose of the lubricant in the present invention accounts for <NUM>%-<NUM>% of the total weight of the oral sustained-release composition.

The glidant comprises but is not limited to talcum powder, colloidal silicon dioxide, silicon dioxide, sodium lauryl sulfate, stearic acid and metal salt thereof. A dose of the glidant in the present invention accounts for <NUM>%-<NUM>% of the total weight of the oral sustained-release composition.

In a preferred embodiment, the oral sustained-release composition comprises the sustained-release granule part and the gel skeleton part, wherein the sustained-release granule part comprises apremilast, the enteric material and the strong liquid sorbent, and the gel skeleton part comprises the hydrophilic gel skeleton material; wherein the enteric material refers to Eudragit S100, and Eudragit FS 30D; the strong liquid sorbent comprises microcrystalline cellulose, croscarmellose sodium, croscarmellose, polyvinylpolypyrrolidone, sodium carboxymethyl starch and low substituted hydroxypropyl cellulose; and the hydrophilic gel skeleton material comprises arabic gum, tragacanth gum, polyvinyl pyrrolidone (PVP or polyvidone), hydroxypropyl methyl cellulose (HPMC), shellac, hydroxypropyl cellulose (HPC), alginate, methylated cellulose (MC), carrageenin, carboxymethyl cellulose and sodium salt, carbomer, and polyvinyl alcohol (PVA); wherein, a weight ratio of the apremilast to the enteric material is <NUM>:<NUM> to <NUM>: <NUM>; and the sustained-release granules are obtained by preparing the insoluble drug and the enteric material into a suspension and then spraying the suspension onto the strong liquid sorbent.

The oral sustained-release composition provided by the present invention is obtained by dispersing the insoluble drug in the liquid substance containing the enteric material to obtain the suspension, and then spraying the obtained suspension onto the strong liquid sorbent to form the sustained-release granule part, and then combining the sustained-release granule part with the material of the gel skeleton part for processing to obtain blended granules, and tableting the granules.

The sustained-release granules in the oral sustained-release composition provided by the present invention may be obtained by wet-granulating process, such as high-shear granulating, fluidized bed granulating and side-spray granulating; and the gel skeleton part may be obtained by direct powder mixing, w wet-granulating process and dry-granulating process.

In the preparation process of the oral sustained-release composition provided by the present invention, the prepared sustained-release granules may be added into the components of the gel skeleton part for granulation together, or the gel skeleton part may be granulated separately and then mixed with the prepared sustained-release granules for subsequent tableting.

In the oral sustained-release composition provided by the present invention, the sustained-release granule part is wrapped by the gel skeleton to form a multiple sustained-release systems. The sustained-release granules in the present invention can form three dissolution and release effects of quick release, sustained release and targeted and controlled release, wherein a part of API not wrapped by the enteric material shows the quick release effect, while a part of holes may be formed during the rapid granulation and drying process, so that the enteric material skeleton shows the sustained release effect in an acidic medium, while a part of the completely wrapped bulk drug shows the enteric targeted and released effect, and the quick-release part of the sustained-release granules can effectively form sustained release because an outer layer thereof is wrapped by the gel skeleton. Moreover, the gel sustained-release layer can effectively resist high-pH environments in the duodenum, jejunum, ileum and other positions, ensuring that a part of the effective ingredients completely wrapped by the enteric material reach the cecum and colon and then release completely, thus forming a stable and effective targeted release effect.

A dissolution rate of the sustained-release granules in the acidic medium may be used for evaluating and detecting a degree of encapsulation of API by the enteric material and a degree of controlling the drug release. With reference to the second method in the general principle (<NPL>on), at a rotating speed of <NUM> rpm, the dissolution rate of the sustained-release granules was determined by using a hydrochloric acid solution of sodium chloride (pH1. <NUM>) with a volume of <NUM> as a release medium and a temperature of <NUM>±<NUM>. A dissolution rate in <NUM> minutes is called an acid dissolution rate.

A target control range of an acid solubility of the sustained-release granules in the present invention is <NUM>%-<NUM>%; and preferably, the control range is <NUM>%-<NUM>%.

Refer to the content uniformity detection method in the general principle (<NPL>on) for the content uniformity detection of the oral sustained-release composition of the present invention. <NUM> sustained-release tablets are taken, a relative content xi of each single dose with a labeled amount of <NUM> is determined, a mean value and a standard deviation S and an absolute value A of a difference between the labeled amount and the mean value are calculated, and then A+<NUM> is calculated. When A+<NUM> is less than <NUM>, it can be considered that the content uniformity is qualified.

The oral sustained-release composition of the present invention may be continuously released for <NUM> hours, wherein the dissolution rate is no more than <NUM>% in <NUM> hours, <NUM>%-<NUM>% in <NUM> hours and more than <NUM>% in <NUM> hours.

The dissolution rate of the oral sustained-release composition according to the present invention is detected at a rotating speed of <NUM> rpm and a temperature of <NUM>±<NUM> with reference to the second method in the general principle (<NPL>on). Six unit doses of samples are tested in parallel. A hydrochloric acid solution of sodium chloride (pH1. <NUM>) with a volume of <NUM> is used as a release medium. After <NUM> minutes, the dissolution rate is tested. <NUM> of <NUM> mol/L sodium phosphate solution with a temperature of <NUM>±<NUM> is added to the above acid solution to continue the operation for <NUM> hours. Then <NUM> of <NUM> mol/L sodium phosphate solution with a temperature of <NUM>±<NUM> is added into the above acid solution (if necessary, the pH value is adjusted to <NUM> with <NUM> mol/L hydrochloric acid solution or <NUM> mol/L sodium hydroxide solution), or according to the time specified under each variety, an appropriate amount of dissolved solution is sucked at a specified sampling point, and filtered, which is completed within <NUM> seconds from sampling to filtration. According to the method specified under each variety, the dissolution rate of each tablet (granule) in a buffer solution is calculated.

Beneficial effects: compared with the prior art, the present invention discloses a technology of wrapping the sustained-release granule part by the gel skeleton to form the double sustained-release system, and the prepared oral sustained-release composition for the low-dose insoluble drug has the following advantages:.

The present invention will be further described in detail below with reference to the embodiments.

The formula and dose ratio used in Embodiments <NUM> to <NUM> were shown in Table <NUM> below, and the total weight of materials in each batch was <NUM> (excluding the weight of solvents).

Preparation process steps of Embodiments <NUM> to <NUM>:.

Samples were taken to detect acid dissolution rates of the sustained-release granules, and each sample contained about <NUM> of apremilast.

The formula and dose ratio used in Embodiments <NUM> to <NUM> were shown in Table <NUM> below, wherein d90 in particle size distribution of API apremilast was <NUM> microns, and the total weight of materials in each batch was <NUM> (excluding the weight of solvents).

The formula and dose ratio used in Embodiment <NUM> were shown in Table <NUM> below, wherein d90 in particle size distribution of API apremilast was <NUM> microns, and the total weight of materials in each batch was <NUM> (excluding the weight of solvents).

Preparation process steps of Embodiment <NUM>:.

The formula and dose ratio used in Embodiments <NUM> to13 were shown in Table <NUM> below, and the total weight of blended granules in each batch was <NUM>.

Dissolution situations of the tablets prepared in Embodiments <NUM> to13 were shown in Table <NUM> below, and the dissolution curves were shown in <FIG>.

The formula and dose ratio used in Embodiments <NUM> to17 were shown in Table <NUM> below, and the total weight of blended granules in each batch was <NUM>.

Dissolution situations of the tablets prepared in Embodiments <NUM> to17 were shown in Table <NUM> below, and the dissolution curves were shown in <FIG>.

The formula and dose ratio used in Embodiment <NUM> were shown in Table <NUM> below, wherein d90 in particle size distribution of apixaban was <NUM> microns, and the total weight of blended granules was <NUM>.

In Embodiment <NUM>, an acid dissolution rate of a certain amount of the sustained-release granules (containing about <NUM> of apixaban) was <NUM>%. A dissolution situation of the prepared tablets was shown in Table <NUM> below, and a dissolution curve was shown in <FIG>.

The formula and dose ratio used in Embodiment <NUM> were shown in Table <NUM> below, wherein d90 in particle size distribution of lenalidomide was <NUM> microns, and the total weight of blended granules was <NUM>.

An acid dissolution rate of the sustained-release granules in Embodiment <NUM> was <NUM>%, a dissolution rate of the prepared tablets was shown in Table <NUM> below, and a dissolution curve was shown in <FIG>.

In Embodiment <NUM>, an acid dissolution rate of a certain amount of the sustained-release granules (containing about <NUM> of tofacitinib) was <NUM>%. A dissolution situation of the prepared tablets was shown in Table <NUM> below, and a dissolution curve was shown in <FIG>.

To distinguish the difference between the present invention and the disclosed technology, the inventor referred to the preparation process of a solid dispersion disclosed in <CIT>, and adopted the similar prescription of sustained-release granules in Embodiment <NUM> of the present invention to prepare samples for comparison.

Therefore, compared with the method recorded in <CIT>, the present invention can significantly reduce the dose of the organic solvent, shorten the drying time, save energy, protect the environment and have high efficiency.

In Comparative Example <NUM>, samples were prepared with reference to the similar prescription of the sustained-release granules in Embodiment <NUM> of the present invention, except that lactose with poor liquid adsorption capacity was used to replace the strong liquid sorbent microcrystalline cellulose, and the obtained sustained-release granules were prepared into tablets by the prescription process in Embodiment <NUM>.

During the experiment, it was found that particle sizes of the sustained-release granules were different, and stratification was easy to occur. The samples were tested, and an acid dissolution rate of the sustained-release granules of Comparative Example <NUM> was <NUM>%, which exceeded the upper limit of the control target by <NUM>%. Content uniformity (A+<NUM>) of the tablets was16. <NUM>, exceeding a qualified limit of <NUM>; and the dissolution rate of the tablets was obviously too fast, as shown in Table <NUM> below.

In Comparative Example <NUM> and Comparative Example <NUM>, tablets were prepared with reference to the sustained-release granule prescription in Embodiment <NUM> and the prescription in Embodiment <NUM> of the present invention, wherein in the sustained-release granule prescription in Comparative Example <NUM>, the tablets of Comparative Example <NUM> were obtained by mixing the sustained-release granule powder with hydroxypropyl methylcellulose K15M PH DC, lactose and magnesium stearate without separate granulation. When granulating the sustained-release granules according to the prescription of Comparative Example <NUM>, bulk drugs were mixed with polyvidone K30 and sodium carboxymethyl starch, and an enteric-coated material, an anti-sticking agent, a plasticizer and a surfactant were separately prepared into a suspension. The subsequent spray-granulation and tableting process was carried out according to Embodiment <NUM> to obtain tablets of Comparative Example <NUM>.

The samples were detected, and content uniformity (A+<NUM>) <NUM> of the tablets of Comparative Example <NUM> and Comparative Example <NUM> were <NUM> and <NUM> respectively, exceeding the qualified limit of <NUM>; a dissolution rate of the tablets of Comparative Example <NUM> was also obviously too fast, and final dissolution of Comparative Example <NUM> was incomplete. A specific dissolution rate was shown in Table <NUM> below.

Compared with Comparative Example <NUM> and Comparative Example <NUM>, Embodiment <NUM> adopting the content of the present invention effectively ensures that the content uniformity of the tablets is within an acceptable range, and the tablet dissolution is slow and lasting, and the final dissolution is complete (the dissolution rate is more than <NUM>% in <NUM> hours).

Claim 1:
An oral sustained-release composition for an insoluble drug, wherein the oral sustained-release composition comprises a sustained-release granule part and a gel skeleton part, the sustained-release granule part comprises the insoluble drug, an enteric material and a strong liquid sorbent; the gel skeleton part comprises a hydrophilic gel skeleton material; and the sustained-release granules are obtained by preparing the insoluble drug and a liquid substance containing the enteric material into a suspension and then spraying the suspension onto the strong liquid sorbent, wherein the insoluble drug in the sustained-release granules accounts for <NUM>%-<NUM>% of a weight of the sustained-release granules, a weight ratio of the insoluble drug to the enteric material is <NUM>: <NUM> to <NUM>: <NUM>, and the strong liquid sorbent accounts for <NUM>%-<NUM>% of the weight of the sustained-release granules; the sustained-release granules account for <NUM>%-<NUM>% of a weight of the oral sustained-release composition; and a dose of the hydrophilic gel skeleton material account for <NUM>%-<NUM>% of the weight of the oral sustained-release composition;
wherein the liquid substance containing the enteric material is in an aqueous dispersion form or an organic solvent solution form of the enteric material, wherein the aqueous dispersion form of the enteric material is obtained by adding water and/or water containing an alkaline substance to the enteric material, and the organic solvent solution of the enteric material is obtained by dissolving the enteric material with an organic solvent;
wherein a solid content of the drug-containing suspension is <NUM>-<NUM>%; and
wherein the strong liquid sorbent is any one of the following group: microcrystalline cellulose, croscarmellose sodium, croscarmellose, polyvinylpolypyrrolidone, sodium carboxymethyl starch, low substituted hydroxypropyl cellulose, starch and pregelatinized starch
wherein the enteric material is a polymer material soluble in a pH range of <NUM>-<NUM>, and the drug coated by the enteric material is capable of being completely released in a position of colon.
wherein the enteric material is any one of a copolymer of methacrylic acid and methyl methacrylate, and a copolymer of methacrylic acid, methyl acrylate, and methyl methacrylate.