JPS60215633A - Intestinally absorbable urokinase liposome composition - Google Patents

Abstract

PURPOSE:The titled composition, obtained by incorporating urokinase liposome containing a higher fatty acid added thereto with an absorption accelerator, e.g. a higher fatty acid, polyalkylene glycol, calcium, etc., and capable of enhancing absorption through intestinal tracts by oral administration, and retaining effective concentration in blood for a long time. CONSTITUTION:An intestinally absorbable urokinase liposome composition consisting of liposome incorporating urokinase and an absorption accelerator, e.g. polyalkylene glycol, calcium or higher fatty acid. The membrane material constituting the above-mentioned liposome contains lipid, e.g. hydrogenated phospholipid, and at least one higher fatty acid, e.g. capric acid. The urokinase is decomposed and inactivated in stomach in oral administration and has low absorption efficiency through intestinal tracts as an enteric agent, but the disintegration is controlled by using the membrane material of the above-mentioned liposome. The incorporation of the above-mentioned absorption accelerator enhances remarkably the intestinal absorption, and a high concentration in blood is maintained.

Description

Detailed Description of the Invention ■9 Background of the Invention (Technical Field) The present invention relates to a novel enterically absorbable urokinase liposome composition, more specifically, a urokinase liposome containing a higher fatty acid, a polyalkylene glycol, and a higher fat-added urokinase liposome. The present invention relates to an intestinally absorbable urokinase liposome composition containing an absorption enhancer such as calcium.

Urokinase is a fibrin and thrombus dissolving enzyme, and is clinically used as a thrombolytic agent to treat various thrombosis diseases such as cerebrovascular occlusion, myocardial infarction, and pulmonary embolism.
It is also used in combination treatment with anticancer drugs.

(Prior art and issues) The route of drug administration is generally classified into injection, oral, external use, etc., but except in special cases, consideration should be given to the complexity and burden on patients, doctors, and other related parties. Oral administration is more useful if the same effect as injection can be obtained by oral administration.

When urokinase is administered orally, it is degraded and inactivated in the stomach by proteases, alcohol, etc., and absorption from the intestinal tract is poor, so conventionally it has been administered by intravenous, subcutaneous, intramuscular injection, or intravenous drip injection. According to these administration methods, urokinase can be administered without being degraded and inactivated, but it requires the intervention of a doctor each time it is administered, and it also has the disadvantage of causing pain to the patient. .

Furthermore, since urokinase has a short half-life in the blood of only about 15 minutes, it is difficult to maintain the blood concentration of urokinase at a constant level using conventional administration methods, resulting in a lack of long-lasting medicinal efficacy.

II. OBJECTS OF THE INVENTION An object of the present invention is to provide an intestinally absorbable urokinase liposome composition with excellent absorption from the intestinal tract.

A further object of the present invention is to provide an intestinally absorbable urokinase liposome composition that is gradually absorbed and has sustained drug efficacy.

9.Specific structure of the invention The present invention is characterized in that it comprises a liposome incorporating urokinase and an absorption enhancer, and the membrane material constituting the liposome contains a lipid and at least one type of higher fatty acid. A urokinase liposome composition is provided.

Preferred absorption enhancers are polyalkylene glycol, calcium and higher fatty acids. Further, the lipid is preferably a hydrogenated phospholipid.

The present invention will be explained in more detail below.

As mentioned above, when urokinase is orally administered, it is decomposed and inactivated in the stomach, and even if enteric coated agents are used to prevent decomposition and inactivation by proteases, acids, etc. in the stomach,
lThe absorption efficiency from the lift tube is poor.

As a result of intensive research, the present inventors found that when absorption enhancers such as higher fatty acids, polyalkylene glycols, and calcium were combined with high-fat fat-added urokinase liposomes, urokinase was unexpectedly absorbed from the intestinal tract by oral administration. The present invention was completed based on the knowledge that the drug is efficiently absorbed and maintains a high blood concentration over a long period of time.

Accordingly, the present invention provides an enterically absorbable urokinase composition containing a liposome incorporating urokinase and an absorption enhancer appropriately selected from higher fatty acids, polyalkylene glycols, and calcium.

The urokinase used in the present invention is not limited in any way as long as it can be administered as a pharmaceutical. The usual molecule used is urokinase of 125,000 to 80,000 human origin.

As the membrane material used in the liposome incorporating urokinase of the present invention, a suitable lipid is used for making the liposome. In particular, the phospholipid includes natural phospholipids such as soybean lecithin, egg yolk lecithin, synthetic phospholipids, or natural phospholipids. Any phospholipid can be used, such as a phospholipid that has been hydrogenated. Since all natural phospholipids contain unsaturated fatty acids, in order to achieve the object of the present invention to a higher degree, it is necessary to use hydrogenated phospholipids in which the unsaturated fatty acids of the natural phospholipids are saturated with hydrogen. is more effective. Synthetic phospholipids can also be used, but are currently very expensive and unsuitable for economic reasons.

Representative examples of phospholipids used in the present invention include phosphatidylcholine, phosphatidylethanolamine,
Phosphatidylinositol, phosphatidylserine,
Examples include phosphatidylglycerol, sphingomyelin, calciolipin, and the like. Further examples include those obtained by hydrogenating these in accordance with conventional methods. Hydrogenated natural lecithin obtained by hydrogenating soybean lecithin, egg yolk lecithin, corn lecithin, cottonseed oil lecithin, rapeseed lecithin, etc. is preferably used.

The higher fatty acids added to the urokinase liposome in the present invention are preferably higher fatty acids having 10 to 20 carbon atoms, examples of which include capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, and linoleic acid. , lyrinic acid, arachidone, and the like. 1 carbon atom, especially with 1 to 4 double bonds
8 to 20 unsaturated higher fatty acids, such as oleic acid,
Linoleic acid, linoleum, and arachidone are preferred, and oleon-resistant is most preferred. These higher fatty acids can be used alone or in combination, and it is preferable that the blending amount is 5 wt% or more and at a concentration (wt%) at which the phospholipids do not form micelles. When the blending amount of higher fatty acids is 5 wt% or more, more preferably 10 wt% or more, excellent effects are exhibited in terms of affinity, stability, sustained release, etc., which are the objectives of the present invention. Unless phospholipids are used in a concentration range that forms a lamellar structure, drugs cannot be retained in liposomes. When the blending amount of higher fatty acids increases, phospholipids mainly contain higher fatty acids to form micelles, and liposomes are no longer formed. The amount of higher fatty acid blended at this time varies depending on the conditions, but is approximately 30 wt%. Therefore, unless the higher fatty acid is used in an amount less than this amount, liposomes will not be formed, and the drug retention efficiency will be extremely reduced or become impossible. Preferably it is 15 wt% or less.

Sterols such as cholesterol and tocopherol can be added to the membrane material of the present invention in order to increase the strength of the membrane, and substances that impart a negative charge to adjust the sustained release of the drug in the living body. For example, phosphatidine,
Dicetyl phosphate can be added. The disintegration of liposome membranes is controlled by the presence of these substances.

The urokinase-loaded liposome used in the composition of the present invention is produced by a method known per se. For example, natural phospholipids, hydrogenated natural phospholipids, at least one of the above-mentioned higher fatty acids and optionally sterols,
A substance giving a negative charge is dissolved in a suitable solvent such as chloroform or ethanol, and the solvent is distilled off from the resulting solution to prepare a phospholipid film. The obtained membrane is dissolved in an appropriate solvent such as chloroform or ether, an aqueous solution of urokinase is added to this solution, and the resulting mixture is vigorously shaken, preferably subjected to ultrasonic treatment, to uniformly disperse the aqueous drug solution. let The solvent is distilled off from the dispersion to obtain urokinase liposomes. The liposome thus obtained is washed with a physiologically acceptable aqueous solution, such as physiological saline, if necessary, and then prepared into pellets, suspensions, granules, or powders.

The higher fatty acid-added urokinase liposomes of the present invention may be freeze-dried under normal conditions, for example, frozen at -20 to -80°C and heated at 0.3 torr.
Preferably, the ice is sublimed under reduced pressure. moreover,
In order to form a good freeze-dried cake, e.g.
Commonly used excipients such as mannitol, dextrin, glycine, etc. may also be added.

The enterically absorbable urokinase liposome composition of the present invention includes:
In addition to the higher fatty acid-added urokinase liposome obtained as described above, it contains an absorption enhancer. In addition, appropriate additives may be included in addition to these. Urokinase liposomes to which higher fatty acids have been added have absorption-promoting properties themselves because they contain higher fatty acids. but,
Since this alone is not sufficient, an appropriate selection from higher fatty acids, polyalkylene gellicols and calcium can be added. The absorption enhancer will be explained in detail below.

The higher fatty acids of the absorption enhancer in the present invention are preferably higher fatty acids having 10 to 20 carbon atoms, examples of which include capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidonic acid, oleic acid, Examples include linoleic acid and linoleic resistance. In particular, unsaturated higher fatty acids having 1 to 4 double bonds and having 18 to 20 carbon atoms, such as oleic acid, linoleic acid, lilunic acid,
Arachidonic acid is preferred, and oleic acid is most preferred.

Examples of the polyalkylene gelicol used as an absorption enhancer in the present invention include polyethylene glycol and polypropylene glycol. The degree of polymerization of polyalkylene glycol is preferably 5 to 500, and the degree of polymerization is 160 to 200.
Particularly preferred are polyethylene glycols.

The absorption enhancer calcium in the present invention is used in the form of a compound that can be administered as a component of a pharmaceutical formulation. For example, it is contained in the composition of the present invention in the form of calcium chloride, calcium lactate, calcium phosphate, or calcium gluconate.

In the composition of the present invention, the blending ratio of higher fatty acid-added urokinase liposomes and an absorption enhancer appropriately selected from higher fatty acids, polyalkylene glycol, and calcium is not critical;
Single fat% 0. OI-2mg, particularly preferably 0.05-0
．． 5 mg, polyalkylene glycol 0.1-5 m
g, particularly preferably 0.1 to 1 mg, calcium 0.0
001 to 0.1 mg, particularly preferably 0.0005 to
It is 0.005 mg.

The compositions of the present invention are formulated for oral or rectal administration in accordance with conventional methods. That is, if necessary, excipients such as calcium carbonate, calcium phosphatide, talc, lactose, dextran, and starch, binders such as gum arabic and tragacanth powder, lanolin, coco oil, etc. are added to prepare tablets and capsules. Or as a suppository. Since urokinase is decomposed and inactivated by gastric juice, it is desirable to coat the tablets or capsules with an enteric coating, such as a film of hydroxypropyl methyl cellulose phthalate, according to a conventional method.

The content of urokinase in one tablet (capsule, suppository) is appropriately selected depending on the administration of urokinase. for example,
For blood clot treatment, at least 100,000 to 50
Since urokinase is administered in 10,000 units, it is desirable to contain 30,000 to 120,000 units of urokinase in one tablet (capsule, suppository).

Next, the present invention will be explained in more detail by showing Examples and Test Examples.

[Example 1] (1) Preparation of higher fatty acid-added urokinase liposome powder 32 mg of lecithin, 15.4 mg of cholesterol and 5 mg of oleic acid were dissolved in 30 mg of chloroform.
I put it in an eggplant-shaped flask. Add isofurovir ether 3d to this, stir and mix, then urokinase 1
One microliter of an aqueous solution containing 0,000 units was added. The resulting mixed solution was sonicated for 5 minutes at a temperature of 4° C. in a water bath type ultrasonic cleaner to be uniformly dispersed. The solvent was distilled off from this dispersion using a rotary evaporator at a temperature of 40'C until Kel was formed. After adding 5 minutes of physiological saline to this gel and stirring, solvent evaporation was continued for an additional 10 minutes, and the liposome suspension was
)is. This suspension is centrifuged at 100,000 G for 30 minutes and washed twice with physiological saline. The obtained pellet was suspended in physiological saline and sterilized to obtain urokinase liposomes. This urokinase liposome was freeze-dried to obtain powdered urokinase liposome.

(2) Preparation of absorption enhancer 0.5 mg of HCO-60 (polyoxyethylene hydrogenated castor oil) was added to 35 m8 of oleic acid and mixed with stirring, followed by polyethylene glycol-eoo.

100 mg was added with 5 mR of water and stirred vigorously to form a uniform dispersion. Then calcium chloride 0.7 mg
was added, dissolved, and freeze-dried to obtain a powder absorption enhancer.

(3) Preparation of the composition of the present invention (3-1) The powdered urokinase liposome prepared in (1) and (2) above (containing 60,000 units of urokinase) and the powdered absorption enhancer were mixed in a ratio of 136 mg. death,
Appropriate amounts of polyethylene glycol and dextran were added to this, and the mixture was filled into Seratin capsules. This capsule was manufactured by applying enteric coating.

(3-2) Powdered urokinase liposome prepared in (1) and (2) above (containing 30,000 units of urokinase)
and a powdered absorption enhancer in a ratio of 136 mg, and appropriate amounts of starch, lactose, and hydroxypropyl cellulose were added to the mixture, which was then compressed into tablets.The tablets were then coated with an enteric coating.

Next, in order to confirm the effect of the intestinally absorbable urokinase composition of the present invention, the following experiment was conducted.

[Experimental Example 1] Comparative Test of Sustainability of Medicinal Efficacy in Rats A capsule of the urokinase liposome composition of the present invention prepared according to Example 1 (3-1) and a commercially available lyophilized preparation were used.

For the experiment, 11-sex Wistar runts weighing 200 to 250 g were used, and 10,000 units of each was administered intragastrically for the capsules of the present invention, and intragastrically or intravenously for the commercially available preparations, and administered hourly. Blood was collected at
- Plasmin inhibitor) activity of the synthetic substrate S-225
1 was used for measurement.

The results are shown in FIG. When the commercially available preparation was administered into the stomach, it was hardly absorbed and α2-PI activity did not decrease. Furthermore, when administered intravenously, a rapid decrease in activity was observed, but the activity recovered quickly and was not sustainable. On the other hand, when the capsule of the present invention was administered, the level decreased to about 60% after 1 hour and continued for more than 6 hours.

[Experimental Example 2] Comparative Test of Durability of Medicinal Effect in Dogs A capsule of the urokinase ribbon composition of the present invention prepared according to Example 1 (3-1) and a commercially available lyophilized preparation were used. In the experiment, healthy peagle-sized animals weighing 9 to 13 kg were used. The capsules of the present invention were administered into the duodenum, and the commercially available preparations were administered into the duodenum or intravenously, and blood was collected at hourly intervals. α2-P in the blood
Synthesis of I (α2-plasmin inhibitor) activity, L!
: Measured using Quality S-2251.

The results are shown in FIG. When the commercially available preparation was administered into the duodenum, it was hardly absorbed and α2-PI activity did not decrease. Furthermore, when administered intravenously, a rapid decrease in activity was observed, but it quickly recovered.
It lacked sustainability.

On the other hand, when the capsule of the present invention was administered, the level decreased to a maximum of 65% after 1 hour and continued for more than 10 hours.

In Figures 1 and 2, the O-marked line is when the present invention agent is administered, the mouth-marked line is the Δ mark when the commercially available preparation is administered to the stomach (Figure 1) and duodenum (Figure 2). The lines indicate the case where commercially available preparations were administered intravenously, and each line is the average value of 10 cases.

(1) Effects of the Invention According to the present invention, a higher fatty acid-added urokinase liposome composition that can be administered enterally is provided. Urokinase alone is hardly absorbed from the intestinal tract, but as mentioned above,
By incorporating an absorption enhancer appropriately selected from higher fatty acids, polyalkylene glycol, and calcium into urokinase liposomes, the receipt of urokinase from the corners can be significantly increased.

Furthermore, the present invention provides a urokinase liposome composition in which the medicinal efficacy of urokinase is sustained. Since urokinase is rapidly degraded in the blood, it is difficult to maintain its drug efficacy for a long period of time using conventional administration methods.

However, in the composition of the present invention, since urokinase is gradually absorbed from the intestinal tract, the concentration of urokinase in the blood can be maintained at a high level for a long period of time, thereby achieving sustained drug efficacy.

Since higher fatty acids are added to the urokinase liposome used in the present invention, the absorption promoting property itself is excellent, but if an absorption promoting agent such as the one described above is added, the effect becomes even more remarkable.

[Brief explanation of the drawing]

Figure 1 is a graph showing changes in plasma α2-PI activity when the composition of the present invention and the control composition were administered to rats through the stomach, and Figure 2 is a graph showing the changes in plasma α2-PI activity when the composition of the present invention and the control composition were administered to dogs. It is a graph showing changes in plasma α2-PI activity when administered enterally. Figure 1: B temple (h,) Figure 2: B temple (hr)

Claims (3)

[Claims] (1) An enterically absorbable urokinase liposome composition comprising a liposome incorporating urokinase and an absorption enhancer, the membrane material constituting the liposome containing a lipid and at least one higher fatty acid. (2) The enterically absorbable urokinase liposome composition according to claim 1, wherein the absorption enhancer is polyalkylene glycol, calcium, and higher fatty acid. (3) The intestinally absorbable urokinase liposome composition according to claim 1, wherein the lipid is a hydrogenated phospholipid.