A vascular permeability suppressant includes an oxaspirooctane derivative of the general formula (I): ##STR1## [wherein, R.sup.1 represents, for example, lower alkylcarbamoyl group or protected carbamoyl group, R.sup.2 represents lower alkoxyl group, and R.sup.3 represents the formula: ##STR2## or a pharmaceutically acceptable salt thereof, together with a pharmaceutically acceptable carrier. Particularly, for example, an agent that can prevent retention of carcinomatous pleural effusion or carcinomatous ascites.

TECHNICAL FIELD
 This invention relates to a novel vascular permeability suppressants, more
 particularly a vascular permeability suppressant which prevents retention
 of carcinomatous pleural effusion or carcinomatous ascites through their
 suppressing action on vascular permeability, and to an agent which
 prevents carcinomatous pleural effusion or carcinomatous ascites
 retention, and also to the method of suppressing retention of
 carcinomatous pleural effusion or carcinomatous ascites by utilizing this
 agent.
 PRIOR ART
 Oxaspirooctane derivatives of the general formula (I):
 ##STR3##
 wherein, R.sup.1 represents carbamoyl group; lower alkylcarbamoyl group;
 hydroxy(lower)alkylcarbamoyl group; lower alkoxy(lower)alkylcarbamoyl
 group; lower alkylthio(lower)alkylcarbamoyl group; lower
 alkoxycarbonyl(lower)alkylcarbamoyl group; lower
 alkylcarbamoyloxy(lower)alkylcarbamoyl group; di(lower)alkylcarbamoyl
 group; N-[hydroxy(lower)alkyl](lower)alkylcarbamoyl group;
 N-[hydroxy(lower)alkyl](lower)alkylcarbamoyloxy(lower)alkylcarbamoyl
 group; lower alkylcarbamoyloxy(lower)alkenoyl group; N-[heterocyclic
 carbonyloxy(lower)alkyl](lower)alkylcarbamoyl group;
 cyclo(lower)alkylcarbamoyl group; arylcarbamoyl group; haloarylcarbamoyl
 group; protected carbamoyl group; lower alkylthiocarbamoyl group;
 heterocyclic carbamoyl group; ar(lower)alkenoyl group; lower
 alkoxycarbonyl group; heterocyclic carbonyl group which may have lower
 alkyl group, hydroxyl group, hydroxy(lower)alkyl group, lower
 alkoxy(lower)alkyl group, or lower alkoxycarbonyl group; lower alkyl
 group; carboxy(lower)alkyl group; protected carboxy(lower)alkyl group;
 ar(lower)alkyl group which may have halogen atom or lower alkoxyl group:
 heterocyclic(lower)alkyl group; lower alkylcarbamoyl(lower)alkyl group;
 hydroxy(lower)alkenoyl group; acyloxy(lower)alkenoyl group or
 diacyloxy(lower)alkenoyl group; R.sup.2 represents lower alkoxyl group,
 and R.sup.3 represents the formula:
 ##STR4##
 the formula:
 ##STR5##
 (wherein R.sup.6 represents protected carboxyl group), the formula:
 ##STR6##
 (wherein R.sup.6 represents the same as described above), the formula:
 ##STR7##
 the formula:
 ##STR8##
 (wherein R.sup.7 represents protected carboxy(lower)alkyl group or
 ar(lower)alkyl group which may have halogen atom), or the formula:
 ##STR9##
 (wherein R.sup.8 represents acyl group), and the process for the production
 thereof are publicly known as described in Japanese Patent Gazette (Kokai)
 No. (Hei)2-85272.
 The angiogenesis-suppressing activity of the above-mentioned oxaspirooctane
 derivatives (I) are known as described in Japanese Patent Gazette (Kokai)
 No. (Hei)2-85272.
 Medicines that suppress vascular permeability itself or medicines that
 prevent the pathological condition that can occur as the result of
 increased vascular permeability, for example serious symptoms due to
 retention of carcinomatous ascites or pleural effusion, have not yet been
 known. Therefore, patients with increased retention of carcinomatous
 ascites or pleural effusion are inevitably treated only with passive means
 such as removal of ascites or pleural effusion with a syringe, etc., and
 thus vascular permeability suppressants serving as agents which actively
 suppress ascites retention or pleural effusion itself have been desired.
 The present inventors discovered in the result of their researches that
 oxaspirooctane derivatives (I) have an excellent suppressing effect on
 vascular permeability and that they also prevent retention of
 carcinomatous ascites or carcinomatous pleural effusion based on the said
 effect. Thus the inventors completed the present invention after extensive
 researches.
 DISCLOSURE OF THE INVENTION
 This invention is concerned with a vascular permeability suppressant, such
 as agents which prevent retention, for example, of carcinomatous pleural
 effusion or carcinomatous ascites, contain an oxaspirooctane derivative
 (I) represented by the above-mentioned chemical formula or a
 pharmaceutically acceptable salt thereof as the active ingredient. The
 said pharmaceutically acceptable salts are exemplified by pharmaceutically
 acceptable conventional salts such as sodium salts, ammonium salts, and
 the like.
 BEST EMBODIMENTS OF THE INVENTION
 The substituents of an oxaspirooctane derivative (I) as the active
 ingredient of the vascular permeability suppressant of this invention, are
 defined in the following.
 "Lower" means the carbon atom number 1 to 6 unless otherwise indicated.
 Preferable "lower alkyl groups" in "lower alkylcarbamoyl group",
 "hydroxy(lower)alkylcarbamoyl group", "lower alkoxy(lower)alkylcarbamoyl
 group", "lower alkylthio(lower)alkylcarbamoyl group", "lower
 alkoxycarbonyl(lower)alkylcarbamoyl group", "lower
 alkylcarbamoyl(lower)alkylcarbamoyl group", di(lower)alkylcarbamoyl
 group", "ar(lower)alkyl group",
 "N-[hydroxy(lower)alkyl](lower)alkylcarbamoyl group",
 "N-[hydroxy(lower)alkyl](lower)alkylcarbamoyloxy(lower)alkylcarbamoyl
 group", "lower alkylcarbamoyloxy(lower)alkenoyl group", "lower
 alkylthiocarbamoyl group", "lower alkyl group", "hydroxy(lower)alkyl
 group", "lower alkoxy(lower)alkyl group", "carboxy(lower)alkyl group",
 "protected carboxy(lower)alkyl group", "heterocyclic(lower)alkyl group",
 or "lower alkylcarbamoyl(lower)alkyl group" may include methyl group,
 ethyl group, propyl group, isopropyl group, butyl group, isobutyl group,
 t-butyl group, pentyl group, hexyl group, etc.
 Preferable "lower alkoxyl groups" in "lower alkoxy(lower)alkylcarbamoyl
 group", "lower alkoxycarbonyl(lower)alkylcarbamoyl group", "lower
 alkoxycarbonyl group", and "lower alkoxy(lower)alkyl group" may include
 methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group,
 hexyloxy group, etc.
 Preferable "lower alkylthio groups" in "lower
 alkylthio(lower)alkylcarbamoyl group" may include methylthio group,
 ethylthio group, propylthio group, butylthio group, pentylthio group,
 hexylthio group, etc.
 Preferable "lower alkenoyl groups" in "lower
 alkylcarbamoyloxy(lower)alkenoyl group", "hydroxy(lower)alkenoyl group",
 "acyloxy(lower)alkenoyl group", "diacyloxy(lower)alkenoyl group" and
 "ar(lower)alkenoyl group" may include C.sub.3 -C.sub.6 alkenoyl groups
 such as acryloyl group, crotonoyl group, etc.
 Preferable "cyclo(lower)alkylcarbamoyl group" is "cylco(C.sub.3
 -C.sub.7)alkylcarbamoyl group", including cyclopropylcarbamoyl group,
 cyclobutylcarbamoyl group, cyclopentylcarbamoyl group, cyclohexylcarbamoyl
 group, cycloheptylcarbamoyl group, etc.
 Preferable "aryl groups" in "arylcarbamoyl group", "haloarylcarbamoyl
 group", "ar(lower)alkyl group", and "ar(lower)alkenoyl group" may include
 phenyl group, tolyl group, xylyl group, naphthyl group, etc.
 Preferable halogens in "haloaryl group" and "halogen" may include chlorine,
 bromine, iodine, and fluorine.
 Preferable "heterocycles" in "N-[heterocyclic
 carbonyloxy(lower)alkyl](lower)alkylcarbamoyl group", "heterocyclic
 carbonyl group", "heterocyclic carbamoyl group", and
 "heterocyclic(lower)alkyl group" may include mono-ring heterocycles
 containing nitrogen atom as the heteroatom (e.g. pyridyl group, pyrrolidyl
 group, piperidyl group, piperazinyl group, 2-oxopyrrolidyl group, etc.),
 mono-ring heterocycles containing nitrogen and oxygen atoms as the
 heteroatoms (e.g. morpholinyl group, etc.), mono-ring heterocycles
 containing nitrogen and sulfur atoms as the heteroatoms (e.g.
 thiomorpholinyl group, etc.), benzene- condensed heterocycles containing
 nitrogen atom as the heteroatom (e.g. quinolyl group etc.), and the like.
 Preferable "protected carbamoyl group" means carbamoyl group protected with
 a conventional carbamoyl-protecting group such as halo(lower)alkanoyl
 group exemplified by trichloroacetyl group, dichloroacetyl group, and
 monochloroacetyl group.
 Preferable "protected carboxyl groups" in "protected carboxy(lower)alkyl
 group" and "protected carboxyl group" may include esterified carboxyl
 groups such as lower alkoxycarbonyl groups (e.g. methoxycarbonyl group,
 ethoxycarbonyl group, propoxycarbonyl group, isopropoxycarbonyl group,
 butoxycarbonyl group, pentyloxycarbonyl group, hexyloxycarbonyl group,
 etc.), and the like.
 Preferable "acyl groups" in "acyloxy(lower)alkenoyl group" and
 "diacyloxy(lower)alkenoyl group" may include lower alkanoyl group (e.g.
 formyl group, acetyl group, propionyl group, etc.), aroyl group (e.g.
 benzoyl group), lower alkanesulfonyl group (e.g. methanesulfonyl group,
 ethanesulfonyl group, etc.), and the like.
 Among the oxaspirooctane derivatives (I) having the groups exemplified
 above, more preferable ones are compounds having lower alkylcarbamoyl
 group or protected carbamoyl group for R.sup.1, lower alkoxyl group for
 R.sup.2, and the group represented by the formula:
 ##STR10##
 for R.sup.3.
 The most preferable compounds are exemplified by:
 6-methylcarbamoyloxy-5-methoxy-4-[2-methyl-3-(3-methyl-2-butenyl)oxiranyl]-
 1-oxaspiro[2.5]octane, and
 6-monochloroacetylcarbamoyloxy-5-methoxy-4-[2-methyl-3-(3-methyl-2-butenyl)
 oxiranyl]-1-oxaspiro[2.5]octane, etc.
 The dosage form of the vascular permeability suppressant or the agent which
 suppresses retention, for example, of carcinomatous pleural effusion or
 carcinomatous ascites based on the said suppressing effect provided by
 this invention is not particularly specified, but the agents are provided
 in various dosage forms including capsules, tablets, granules, powders,
 buccal preparations, sublingual preparations, liquid preparations, etc.
 with pharmaceutically acceptable carriers combined. These pharmaceutical
 preparations are orally or parenterally administered to mammals including
 man.
 The pharmaceutically acceptable carriers may include various organic and
 inorganic carriers conventionally used for formulation. That is, fillers
 (e.g. sucrose, starch, mannitol, sorbitol, lactose, glucose, cellulose,
 talc, calcium phosphate, calcium carbonate, etc.), binders (cellulose,
 methylcellulose, hydroxypropylcellulose, polypropyl pyrrolidone, gelatin,
 acacia, polyethylene glycol, sucrose, startch, etc.), disintegrators
 (starch, carboxymethylcellulose, calcium carboxymethylcellulose,
 hydroxypropyl starch, sodium glycol starch, sodium hydrogencarbonate,
 calcium phosphate, calcium citrate, etc.), lubricants (e.g. magnesium
 stearate, aerosil, talc, sodium lauryl sulfate, etc.), flavors (e.g.
 citric acid, menthol, glycine, orange powder, etc.), preservatives (e.g.
 sodium benzoate, sodium bisulfate, methylparaben, propylparaben, etc.),
 stabilizers (e.g. citric acid, sodium citrate, acetic acid, etc.),
 suspending agents (e.g. methylcellulose, polyvinyl pyrrolidone, aluminum
 stearate, etc.), distributing agents (e.g. surfactants, etc.), aqueous
 diluents (e.g. water), oils (sesame oil, etc.), and base wax (e.g. cacao
 butter, polyethylene glycol, white soft paraffin, etc.) can be used.
 The dose of an oxaspirooctane derivative (I) may depend on kinds of the
 compound (I) as well as other various factors including the nature of the
 underlying disease causing increased vascular permeability, for example
 the nature and the site of cancer, body weight and/or age of the patient,
 and administration route. The preferable dose may be selected normally
 from the range of 0.01 to 10 mg/kg/day for injection and 0.5 to 50
 mg/kg/day for oral administration.

The invention will be more clearly understood with reference to the
 following Test Examples.
 TEST EXAMPLE 1
 (1) Test Compound
 6-Methylcarbamoyloxy-5-methoxy-4-[2-methyl-3-(3-methyl-2-butenyl)oxiranyl]-
 1-oxaspiro[2.5]octane
 (2) Formulation
 a. Sustained Release Preparation
 TABLE 1
 Amount combined (g)
 Preparation of the Placebo
 Ingredient invention preparation
 Test compound 1.00 0.00
 LGA-5010 (Note 1) 5.00 5.00
 Carplex (Note 2) 0.04 0.04
 (Note 1): A biodegradable polymer compound obtained from reaction of lactic
 acid and glycolic acid (Wako Pure Chemical Industries, LTD.)
 (Note 2): Silicone dioxide hydrate (Shionogi & Co., Ltd.)
 The sustained release preparation was stored in a freezer.
 b. Vehicle
 TABLE 2
 Ingredient Amount combined (g)
 aluminum stearate 3.0
 sesame oil 97.0
 The vehicle was stored at room temperature.
 Immediately before administration to test animals, the above-mentioned
 sustained release preparation (60.4 mg: corresponding to 10 mg of the test
 compound in the preparation of this invention) was added to the
 above-mentioned vehicle (20 ml) and the mixture was slightly stirred with
 a spatula, to give a suspension.
 (3) Tumor Cells and Preparation of Cells for Implantation in Test Animals
 Tumor cells used were Meth A fibrosarcoma (mouse fibrosarcoma), and
 subcultured every 7 days in the peritoneal cavity of BALB/c strain mouse.
 The resultant Meth A cells were washed with Hanks' solution, and suspended
 in Hanks' solution. The viable cells were counted with the Trypan blue dye
 exclusion method. Cell preparations of 5.times.10.sup.6 cells/ml and of
 1.25.times.10.sup.7 cells/ml were made for intrathoracic implantation and
 for intraperitoneal implantation in the test animals.
 (4) Administration Schedule
 a. Effect on Retention of Carcinomatous Pleural Effusion
 BALB/c strain mice were divided into two groups (6 animals per group), and
 Meth A cells (5.times.10.sup.5 cells/0.1 ml/mouse) were implanted into the
 thoracic cavity of each mouse. To animals of one group was subcutaneously
 administered the preparation of this invention (10 mg/kg) on 3 occasions,
 i.e. on the day of implantation, 2 days later, and 4 days later. To the
 animals of the other group was administered the placebo preparation
 according to the same dosing schedule. Six days after implantation of the
 tumor cells, pleural effusion was obtained.
 b. Effect on Retention of Carcinomatous Ascites
 BALB/c strain mice were divided into two groups (6 animals per group), and
 Meth A cells (2.5.times.10.sup.6 cells/0.2 ml/mouse) were implanted into
 the peritoneal cavity of each mouse. To animals of one group was
 subcutaneously administered the preparation of this invention (10 mg/kg)
 on 3 occasions, i.e. on the day of implantation, 2 days later, and 4 days
 later. To the animals of the other group was administered the placebo
 preparation according to the same dosing schedule. Seven days after
 implantation of the tumor cells ascites was obtained.
 (5) Test Results
 a. Effect on Retention of Carcinomatous Pleural Effusion
 The amount of the pleural effusion obtained was measured. Then the cells in
 the thoracic cavity (including tumor cells) were removed by
 centrifugation, and the volume of the pleural effusion after removal of
 the cells was measured. The results are shown in Table 3. Each value is
 the mean .+-.S.E. In the Table, the number of mice in the placebo-treated
 group is 2 because, as described below, 4 of 6 mice died so that only the
 data of the remaining 2 animals could be obtained.
 TABLE 3
 Pleural effusion retained (ml)
 including
 cells in Without cells
 Treatment Number of thoracic in thoracic
 group mice cavity cavity
 Placebo 2 1.1 .+-. 0 0.7 .+-. 0.1
 preparation
 Preparation of 6 0.4 .+-. 0.1** 0.2 .+-. 0.1*
 this invention
 *p &lt; 0.05 vs placebo **p &lt; 0.01 vs placebo
 (Student's t test when the variance is equal, Aspin-Welch's t test when the
 variance is not equal)
 The total amount of retained pleural effusion (including the cells) was 1.1
 ml in the placebo-treated group and 0.4 ml in the group treated with the
 preparation of this invention, demonstrating the significant pleural
 effusion retention-suppressing effect of the preparation of this
 invention. The amount of pleural effusion after removal of the cells in
 the thoracic cavity was 0.7 ml in the placebo-treated group and 0.2 ml in
 the group treated with the preparation of this invention, demonstrating
 again the significant pleural effusion retention-suppressing effect of the
 preparation of this invention.
 Four of the 6 animals of the placebo group died but no animals died in the
 group treated with the preparation of this invention, indicating a
 significant life-prolonging effect of the preparation of this invention.
 b. Effect on Retention of Carcinomatous Ascites
 The amount of the ascites obtained was measured. Then the cells from the
 peritoneal cavity (including tumor cells) were removed by centrifugation,
 and the volume of the ascites after removal of the cells was measured. The
 results are shown in Table 4. Each value is the mean .+-.S.E. No mice died
 in this experiment.
 TABLE 4
 Ascites retained (ml)
 including
 cells in without cells
 Treatment Number of peritoneal in peritoneal
 group mice cavity cavity
 Placebo 6 3.5 .+-. 0.3 2.2 .+-. 0.2
 preparation
 Preparation of 6 1.0 .+-. 0.1** 0.5 .+-. 0.1**
 this invention
 **p &lt; 0.01 vs placebo
 (Student's t test when the variance is equal, Aspin-Welch's t test when the
 variance is not equal)
 The total amount of retained ascites (including the cells) was 3.5 ml in
 the placebo-treated group and 1.0 ml in the group treated with the
 preparation of this invention, demonstrating the significant ascites
 retention-suppressing effect of the preparation of this invention. The
 amount of ascites after removal of the cells in the peritoneal cavity was
 2.2 ml in the placebo group and 0.5 ml in the group treated with the
 preparation of this invention, demonstrating again the significant ascites
 retention-suppressing effect of the preparation of this invention.
 TEST EXAMPLE 2
 (1) Test Compound
 6-Monochloroacetylcarbamoyloxy-5-methoxy-4-[2-methyl-3-(3-methyl-2-butenyl)
 oxiranyl]-1-oxaspiro[2.5]octane
 (2) Formulation
 For the preparation of this invention, was used the solution of 86.0 mg of
 the test compound in 3.0 ml of propyleneglycol contained in a minipump
 (Note 1). For the placebo preparation, was used only the above-mentioned
 propyleneglycol contained in a minipump. Note 1: AZLET Mini-Osmotic Pump
 Model 2001: This can release a medicine solution continuously for 7 days
 at the mean pumping rate of 1.0 .mu.l/hour.
 (3) Tumor Cells and Preparation of Cells for Intrathoracic Implantation in
 Test Animals
 The cells were prepared under the same conditions as those for Test Example
 1.
 (4) Treatment Schedule for Investigating the Suppressing Effect on
 Retention of Carcinomatous Pleural Effusion
 BALB/c strain mice were divided into 2 groups (5 animals per group), Meth A
 cells (5.times.10.sup.5 cells/0.1 ml/mouse) were implanted in the thoracic
 cavity of each animal. The preparation of this invention contained in the
 above-mentioned minipump was implanted subcutaneously on the day of the
 implantation in one group, while the placebo preparation was administered
 in the other group according to the same schedule. In the group treated
 with the preparation of this invention, the animals received the test
 compound at the dose of 32 mg/kg/day. Five days after implantation of the
 tumor, the pleural effusion was obtained.
 (5) Test Results
 The measurement was made with the same method as in Test Example 1. The
 results are shown in Table 5. Each value is mean .+-.S.E.
 TABLE 5
 Pleural effusion
 retained (ml)
 including
 cells in without cells
 Treatment Number of thoracic in thoracic
 group mice cavity cavity
 Placebo 5 0.7 .+-. 0.1 0.5 .+-. 0.1
 preparation
 Preparation of 5 0.1 .+-. 0.0* 0.1 .+-. 0.0*
 this invention
 *p &lt; 0.05 vs placebo
 (Student's t test when the variance is equal, Aspin-Welch's t test when the
 variance is not equal)
 The total amount of retained pleural effusion (including the cells) was 0.7
 ml in the placebo preparation treated group and 0.1 ml in the group
 treated with the preparation of this invention, demonstrating the
 significant pleural effusion retention-suppressing effect of the
 preparation of this invention. The amount of pleural effusion after
 removal of the cells in the thoracic cavity was 0.5 ml in the placebo
 group and 0.1 ml in the group treated with the preparation of this
 invention, demonstrating again the significant pleural effusion
 retention-suppressing effect of the preparation of this invention.
 TEST EXAMPLE 3
 (1) Test Compound
 The same compound as in Test Example 2.
 (2) Formulation
 For the preparation of this invention, was used the solution of 105 mg of
 the test compound in 6.0 ml of physiological saline containing 10%
 polyoxyethylene hydrogenated castor oil (HCO-60). For the placebo
 preparation, was used the above-mentioned physiological saline containing
 only 10% polyoxyethylene hydrogenated castor oil.
 (3) Preparation of Tumor Cells and of Tumor Cell-derived Vascular
 Permeability Promoter
 Tumor cells used were Meth A fibrosarcoma (mouse fibrosarcoma) prepared by
 subculture under the same conditions as for Test Example 1, and implanted
 in mice. From mice 6 days after implantation, ascites was obtained, and
 the supernatant of the ascites after removal of tumor cells (2000 rpm, 10
 min.) was used as the tumor cells-derived vascular permeability promoter.
 (4) Administration Schedule
 Hartley strain guinea pigs were divided into 2 groups (4 animals per
 group), and the preparation of this invention was administered
 subcutaneously in one group (dose: 32 mg/kg). In the other group, the
 placebo preparation of the same volume was administered subcutaneously.
 One hour after administration, 1 ml of the solution of Evans blue in
 physiological saline (10 mg/ml) was injected intravenously, followed by
 immediate subcutaneous administration of 0.1 ml of the ascites
 supernatant. Thirty minutes later the skin of each guinea pig with leakage
 of Evans blue was sampled, and soaked in 1 ml of 0.1N-KOH overnight to be
 solubilized. After solubilization, 4 ml of acetone-2.5N phosphoric acid
 mixture (17:3) was added to extract Evans blue, and OD.sub.620 of the
 extract was determined.
 (5) Test Results
 The results of determination of OD.sub.620 of the extract are shown in
 Table 6. Each value is the mean .+-.S.E.
 TABLE 6
 Number of
 Treatment group mice OD.sub.620
 Placebo 4 0.117 .+-. 0.009
 preparation
 Preparation of this 4 0.082 .+-. 0.003*
 invention
 *p &lt; 0.05 vs placebo
 (Student's t test when the variance is equal, Aspin-Welch's t test when the
 variance is not equal)
 The OD.sub.620 value in the placebo group was 0.117 whereas the value was
 0.082 in the group treated with the preparation of this invention, clearly
 showing that the leakage of Evans blue through the vessels was
 significantly decreased after administration of the preparation of this
 invention. That is, it was demonstrated that the preparation of this
 invention can significantly suppress the vascular permeability-promoting
 effect ascribable to the tumor cells-derived vascular permeability
 promoter.
 Industrial Applicability
 This invention is constituted as described above, and therefore can provide
 vascular permeability suppressants, particularly agents that can prevent
 retention of carcinomatous pleural effusion or carcinomatous ascites.