3',5'-Camp Derivatives for Treatment of Certain Types of Skin Ulcers

(1) Field of the Invention

This invention relates to a novel therapeutic agent for skin ulcers.

(2) Description of the Prior Art

As skin ulcers generally mentioned are pressure gangrenes caused from circulation disorders due to pressure suffered for a long period; gangrenes derived from diabetes or cerebral infarction; thermal burns; frostbites; radionecrosis and so on.

These skin ulcers are difficult to be healed once they occur. Treatments currently carried out are internal treatments in which antibiotics, kallikrein, anginin [pyridinol carbamate (Banyu)], nicotinic acid or antiphlogistic protease preparations are administered locally or totally, and surgical treatments in which disinfectants, steroid hormones, antimicrobial preparations and the like are externally applied.

Internal administrations, however, sometimes fail to give an expected improvement because only a part of the administered medicine reaches and acts on the affected part. Besides, they cannot avoid side effects produced. From these reasons, external preparations would be advisable. However, few medicines were known to be effective which could directly act on the skin and heal the affected part. This have had made the treatment of skin ulcers difficult.

Under the above situation, the present inventors have earnestly carried out studies in order to provide an external preparation effective for healing skin ulcers, and have found that adenosine-3',5'-cyclic phosphate (hereafter may be referred to as "c-AMP") or its derivatives are very effective. The present invention was accomplished based on the above finding.

Accordingly, this invention provides a therapeutic agent for skin ulcers comprising as its active component adenosine-3',5'-cyclic phosphate or a derivative of the cyclic phosphate.

c-AMP derivatives usable in this invention include N.sup.6 -monoacyladenosine-3',5'-cyclic phosphate, 2'-O-monoacyladenosine-3',5'-cyclic phosphate, N.sup.6,2'-O-diacyladenosine-3',5'-cyclic phosphate or their 8-mercapto, 8-lower alkylthi, 8-benzylthio, 8-amino, 8-hydroxy, 8-chloro or 8-bromo substitutions, 8-benzylthioadenosine-3',5'-cyclic phosphate or its N.sup.6 -lower alkyl substitution or 8-mercaptoadenosine-3',5'-cyclic phosphate. c-AMP and these derivatives are all known compounds which are described in Japanese Patent Publication (Tokkyo Kokoku) No. 22559/1975, "Nippon Rinsho", vol. 40, No. 11, pp 14-19, 1982, Journal of Cyclic Nucleoide Research, 2, pp 307-319(1976) and Biochim. Biophys. Acta, 148 (1967), 99-105.

The therapeutic agents for skin ulcers according to this invention can be prepared into various forms such as solutions, emulsions, ointments, creams, lotions, poultices and the like by incorporating c-AMP or its derivatives into a base. As to the base, any known base materials are usable. Preferable preparations are solutions obtained by dissolving c-AMP or its derivatives in a physiological saline solution and ointments using macrogol as a base. The amount of c-AMP or its derivatives to be incorporated is varied in a wide range, and normally, 3 wt % of the quantity of the base is preferable.

The therapeutic agents according to this invention are generally applied to the affected part from once to several times a day, each time in such an amount that c-AMP or its derivatives are contained 3 mg-3 g/100 cm.sup.2 and more preferably 50-1000 mg/100 cm.sup.2 depending on the degree and area of ulceration.

This invention is now explained in more detail by way of examples, which should not be construed as limiting the invention.

(1) A solution was prepared by dissolving 300 mg of sodium bucladesinate (N.sup.6,2'-O-dibutyryladenosine 3',5'-cyclic sodium phosphate) in 10 mg of physiological saline solution.

(2) An ointment was prepared by using 50 g of Macrogol 4000, 50 g of Macrogol 400 and 3 of sodium bucladesinate by a usual manner.

A 60 year old male patient who was diagnosed pyoderma gangrenosum in the lower part of the left thigh was treated with various ointments, pig skin applications, intravenous drip and the like, but there were no significant improvements observed.

This patient was then treated with 5 mg sodium bucladesinate solution (content of sodium bucladesinate: 150 mg) obtained in Example 1 (1) which was soaked in guaze and applied to the affected part once a day. A few days later, the ulceration area was observed to be reduced, and about 2 months later, the ulceration was completely epithelializated and healed.

Several ulcers shown in Table 1 were treated using an ointment of sodium bucladesinate obtained in Example 1 (2). In each case, the ointment was applied to the affected part in such an amount that sodium bucladesinate was contained 50-1000 mg/100 cm.sup.2.

The results are also shown in Table 1. The data indicate excellent therapeutic effects for all cases. In the table, the letter "w" means week. Administra- Suffering tion Side Effective- Name Sex Age Diagnosis Basic Disease Period Prior Treatment Symptoms Period Progress Effects ness About 1 month treatment Ulceration with white After a few days of administra- by Gentacin ointment coverings and faulty tion, the white coverings began [gentamicin C.sub.1a granulations in the to disappear and benign reddish (Schering/Shionogi)] lumbar region. granulations appeared; Ulceration I. M. f 86 Decubitus Cervical About found invalid. area rapidly reduced to 14.0 (7.0 Very carcinoma 1 month 6w .times. 2.0) (1w), 4.5 (3.0 .times. 1.5) (2w) None Effective and 2.76 (2.3 .times. 1.2) (4w). After 6 weeks, epidermis was formed with thin crust remained partially and almost healed. Rupture of 2 month treatment by Ulcerations of After 1 week of administration, the bladder; Hibitane cream [chlor- 420 (20 .times. 21) in the granulations turned to hemor- Peritonitis; hexidine (Sumitomo)], lumbar region and rhagic and muscle color to fresh Fracture of Rinderon A ointment 110.5 (13 .times. 8.5) in the red. After 3 weeks, the the lumbar [fradiomycin sulfate, femoral region; thigh ulceration area reduced to K. K. f 72 Decubitus vertebrae; sodium betamethasone bone, head thereof and 360.0 (18 .times. 20) in the rear Palsy in the 9 months phosphate (Shionogi)] ilac bone are partially 4w lumbar part and 85.0 (12.5 .times. 6.8) None Effective left side found invalid. exposed and the muscle in the thigh (85.7% and 76.9%, 7 month treatment by appears old meat; respectively). Solcoceryl Strong ischaemia; [deproteinized extract Systemic conditions 4w: Death from basic disease obtained from very bad, terminal hemolysate of calves stage. (Tobishi)], Isalopan ointment [aluminum chloroxy allantoinate (Grelan/Takeda)], Stable Trypure [trypsin (Kodama)] found invalid. 5 month treatment by Deep ulceration of After 3w of administration, Solcoceryl, Elase C 2.7 (1.9 .times. 1.4) in the granulations began to have very [fibrinolysin, lumbar region; Granula- good appearance. Ulceration deoxyribonuclea se tions slightly faulty; area reduced. (Sankyo)] revealed Wound region tends to 3w: 1.5 (1.9 .times. 0.8), T. I. m 37 Decubitus Encephalopathy 6 months a little improvement. tear sideways because 6w: 1.0 (2.0 .times. 0.5), (Vegetation) Thereafter, 1 month the patient strongly 7w 7w: 0.6 (1.6 .times. 0.4) = 22.2% None Effective treatment by mercuro- presses his lumbar part chrome found invalid. to the floor when he changes the position of his upper part or lower part due to rigidity. Gastric Treatment by Isodine Ulceration of 3.7 After 1w, granulations turned to ulcer; [povidone iodine (1.6 .times. 2.3) in the be dry, no exudate; after 2w, Y. M. m 57 Decubitus Peritonitis; 2w (Meiji Seika)], lumbar region; 4w very good conditions; after 4w None Very Pulmonary excerbation Granulations slightly completely healed. Ulceration effective insufficiency faulty area: after 2w, 2.5 (1.3 .times. 1.9), after 3w; 1.0 (0.9 .times. 1.1), after 4w, completely healed. Left cervica Geben cream [silver Ulceration with light 1w of administration brought Ulcer- tumor (squa- sulfadiazine (Tokyo yellow gelly substances significant reduction. ation mous cell about Tanabe)], intractable in the left region of 1w Before Administration: None Very R. S. m 55 from carcinoma); 2.5 neck 2.1 (2.1 .times. 1.0 cm) effective radiation Hypertension months 1w: 0.19 (0.95 .times. 0.2 cm) = 9.0% Diabetes Ambustion 5 weeks of treatment Ulceration of 1.3 After 1w, 0.8 (0.6 .times. 0.3), dry, R. H. f 7 (II) None 5w by Geben cream, no (1.3 .times. 1.0) in the 2w no exudate. None Very effect right-lower thigh After 2w, completely healed. effective Elase ointment, Deep ulceration in 1w: dry, soft black crust removed; Gentacin ointment side region of the Ulceration definitely H. K. m 25 Ambustion None 2w external application of right-low er thigh by a 6w disappeared and skin grafting None Very II Fucidin Leo Intertulle foot warmer. considered unnecessary. effective [sodium fusidate Partially blacken with Prior to Administration: (Sankyo)] by other dirty yellow coverings 5.6 (2.8 .times. 2.0 cm) hospital found invalid. 1w: 3.8 (2.4 .times. 1.6 cm) Came to this hospital 2w: 1.3 (1.5 .times. 0.85 cm) to have skin grafting 5w: 0.1 (0.4 .times. 0.2 cm) of erosion 6w: healed Geben cream found Deep ulceration with 1 day: dried Iron about invalid. white coverings in 2 days: circumpherencial erosion O. S. f 52 Leg ulcer deficiency 2 Elase C found invalid. the inside of the healed None Effective anemia months left leg; Painful About 2w: dry crust Strong pain was suffered in the 1 st day and the pain decreased from the next day. After 2 weeks, pain almost disappeared. Prior to Administration: 2.5 (1.8 .times. 1.4 cm) 1w: 1.2 (1.0 .times. 1.2 cm) 2w: 1.0 (0.9 .times. 1.1 cm) 4w: 0.4 (0.5 .times. 0.8 cm), crust 6w: 0.2 (0.4 .times. 0.55 cm) Returned home but came back to the hospital again due to excerbation caused by being frequently forced to maintain upright posture at home. Blisters and blood blisters were formed 1w: no exudate in legs due to 2w: very shallow erosion, ulcer H. S. m 27 Frostbite None 1w None frostbite. No sense About area reduced, sense come None Very at all. 8w back again effective Removal of Nercosis 4w: 1.0 .times. 0.75 cm epidermis resulted 5w: dry erosion in deep ulceration. 8w: completely healed, normal sensation

Vulnerary effects of sodium bucladesinate and 8-benzylthio-N.sup.6 -butyladenosine-3',5'-cyclic phosphate (hereafter abbreviated to BTBcAMP) were investigated by the following test. The results are shown in Table 2.

Several groups of SD male rats (8 weeks old, weighing 225-285 g), each group consisting of three rats, were used. The hair in the abdominal region was removed and then the local skin was excoriated to have a lesion of 3 cm in diameter under etherization to prepare a full-thickness avulsion model. Test samples were sodium bucladesinate and BTBcAMP. They were applied 60 mg each for the first day of the treatment, and 30 mg each for the second and the third day. The samples were applied as they were. The lesion area of each rat was measured after 0, 24, 48 and 72 hours respectively, and an average value of reduction ratio obtained was regarded as reflecting the vulnerary effect.

From the above data, it is understood that the groups which were treated with sodium bucladesinate and BTBcAMP were rapidly healed compared with Control (No treatment carried out).