MXPA97001779A - Implantable molded body for administering active substances to plan - Google Patents

Abstract

The present invention relates to polymer bodies molded, partially biodegradable, implantable to administer active substances to plants. The molded bodies are characterized in that they contain at least one hydrophobic polymer

Description

MOLDED BODY 1MPLANTABLE TO ADMINISTER ACTIVE SUBSTANCES TO PLANTS FIELD OF THE INVENTION The invention relates to bodies with certain forms containing polymers, implantable, partially biodegradable, intended to administer active principles to plants. Unlike human and veterinary medicine, the administration of active ingredients to plants with the help of implantable devices is little known. The formulations of the active ingredients customary in practice are sprayed on the plants or introduced at ground level, close to their roots. A disadvantage of these conventional forms of application are the high losses produced during the application, which on the one hand, represent high environmental loads (air, soil and water pollution), and on the other hand, make high dosages necessary of the active substance The disadvantage of the high losses of the active ingredient is of particular importance when adopting means of plant protection in urban areas (trees in malls, urban parks) or when, during a patent period, it is necessary to repeat them several times. applications, which is, for example, the case in agricultural crops with high attacks by parasites.

BACKGROUND In order to reduce to a minimum, on the one hand, the environmental risks derived from the phytosanitary treatment and, on the other hand, to achieve a longer duration of the active ingredients, numerous alternative active ingredient administration systems have been developed in the past. Among these are those systems described in the European patents EP 0 254 196 and German DE 39 22 366. These refer to devices for the transcuticular or transperidermal application of the systemic active principles to plants. These are preparations in the form of deposits such as surface systems similar to adhesive patches and contact adhesives, which are conveniently applied at a specific place along the growth axis of the plant. On the other hand, those forms of administration indicated in DE-GM 17 60 060 and in the patent of E. U.A. 4, 766,695. Here it is only tree rings that contain insect repellent or destructive active ingredients, and thus protect the plant externally. The printed documents do not contain a clear reference that they are systems for the systemic administration of active principles, but it can be assumed that due to their construction and composition they operate as such systems. The administration systems mentioned up to now, in the present invention, are applied externally on the surface of the plants. Thus, said systems have the disadvantage that their operating capacity, based on a problem-free adhesion, is influenced by the external conditions. On the other hand, it is necessary to eliminate these devices once the system is exhausted. Furthermore, this type of application does not allow a satisfactory administration of the active principles, because their resorption is hindered by barriers in the form of impermeable end fabrics. A direct administration of the active principles to the system of conductive vessels of the plant by injection, which is described in the patents of E. U.A. N os. 4,078, 087, 4, 103,456, CA 1, 089,645, and in the patent of E. U.A. 3, 576,276, they make it possible to obviate the drawbacks mentioned above, but present other drawbacks. Since the delivery of the active ingredient occurs very quickly and directly to the plant's conductive system, it is related to the potential dangers of very high concentrations of the active substance with corresponding damage to the plant. Another disadvantage is that several repetitions of the treatment are required, so that a required concentration of the active substance can be ensured over a prolonged period. Said disadvantages can be avoided by the use of administration devices, which are placed inside the plant and at the same time allow to ensure a continuous and long-term supply of the active ingredients.

A supply of the principles or active substances to the plants with the help of implantable application systems has already been mentioned in the specialized literature (patent AU 8431497 and Japanese J P58039602), but until now it has not reached a commercial level. The patent AU8431 497 refers to an im plantable device in the form of a porous body of ceramic material, which is placed in an orifice created mechanically in the trunk, and which is connected to an external deposit of the active ingredients with the capillary tubes help. The supply of the active principle, which occurs in two partial stages, in particular the transport from the tank and the passage through the porous body, is carried out by means of the use of the pressure in the ducts produced by the perspiration and the forces capillaries of the porous implant. The main drawback of such an application system thus lies in the fact that the supply of the active principles to the plant depends exclusively on the moisture balance of the plant, which in the case of a strong transpiration intensity can produce a excessive concentration of the active ingredient. During the use of this device, it is practically impossible to achieve an accurate dosage of the active principle. Apart from this, the application of the system is difficult, since the implanted bodies must be re-injected once the treatment is finished. The system of administration described in the publication J P 58039602 makes it possible to obviate the drawbacks described above. Here we are dealing with bodies formed or with a certain shape that contain the active principle of implantable type with different configurations (tablets, rods, discs, etc.) formed from a mixture of substances strongly absorbing water, such as for example , the starch-acrylamide copolymers, the starch-acrylonitrile copolymers and the hydrophilic polymers, such as the ethylene-vinyl acetate copolymers. These systems are used for the supply of biologically active substances to trees, among them also to attack diseases that require prolonged treatments, such as, for example, of Ceratocistis spp. (In Pinus silvestris). They are introduced in the perforation previously made in the trunk, where they remain for prolonged periods. The swelling produced as a consequence of a strong recovery of moisture, results in a considerable increase in volume, which has as a consequence that all the available space for the implant is being occupied and the previously arranged opening is hermetically clogged. There is no direct reference in the publication, which is concerned with biodegradable implants, but it is clear that considering their chemical composition, they are degraded at least partially in the plant organism. Thus, within the framework of the present application, they can be classified as partially biodegradable and have the advantage that they are no longer needed to be removed from the plants after use.

However, these systems present numerous problems, which result, first, from their chemical construction. Because they consist exclusively of hydrophilic polymers, they are suitable for the incorporation of strongly lipophilic substances, only to a limited extent. Especially when a relatively high loading of active ingredient is required, these implant systems are not suitable. On the other hand, they have the drawback that a hydrophilic polymer matrix delivers the active principle after introduction into the plant tissue with a relatively high level of cellular hydration. As a result, relatively high concentrations of the active ingredient are achieved, but the system has run out after a short time. In numerous practical cases of supply of the active principle to plants, for example in the treatment of diseases that occur periodically with a high pressure of infection or the action of the parasites, it is required to maintain an effective concentration for a prolonged period. In such applications (for example, the attack by the shell can be mentioned, in the case of the apple trees in the zones of high level of precipitation or in the case of the attack by the blasthole of the shoots, in the case of the crops of bananas), polymers are required as carriers, which grant the system the properties of a deposit. Also the problem of the loss of active principle can not be satisfactorily resolved in the case of these systems. As mentioned, the formation of a very intimate contact between the body of the implant and the limit surfaces of the hollow space in the plant depends strongly on the uptake of water and thus on the state of hydration of the tissue cells in the tissue. place of application. It is a known fact that the osmotic relationships of the parts of the plant, according to the degree of solicitation of balance, are exposed to strong variations. Extremely low or extremely high water potentials can produce strong variations in the volume of the implant and thereby modify the hermetic closure of the opening in the trunk. Another disadvantage of these systems is ultimately their relatively poor thermoplastic processing capacity as well as the insufficient mechanical properties, which are also the result of the hydrophilic character of the structural polymers. The object of the present invention was to propose a solution for the aforementioned problem, creating systems of administration of biodegradable active principles suitable for incorporation into plants, which are suitable for quick and short release as well as a long and enduring principle active, presenting satisfactory mechanical properties and where the formed masses used for its manufacture can be processed thermoplastically free of problems.

DESCRIPTION OF THE INVENTION According to the present invention this objective has been achieved with the aid of bodies formed as indicated in claim 1. The invention will be described in detail below. Implanted, partially biodegradable shaped bodies formed basically of polymers are proposed which contain at least one hydrophobic polymer. The term "biologically degradable" is understood in the present application as "biodegradable", that is to say "biodegradable under stimulation by means of an active biological medium". By this is meant a formed body, which has access to the metabolism of higher plants and which can also be degraded in microbial form. The biodegradation produces the simultaneous release of the active principle and is produced by the bioerosion in the plant. In the degradation of the products according to the invention, the known fragments are mainly formed through biotolerance, which can be metabolized in the natural metabolisms of the plant. The intensity and extent of the degradation of these bodies in the plant organism depends on the type of the implant materials. The degradation time can be adapted by an appropriate choice of raw materials to the requirements raised. This property is particularly suitable for the usual practice in gardening from the point of view of the administration of the active principle, because these systems both in their application oriented to the long term as well as in the short term treatment can be applied free of charge. problems. Thanks to their capacity of biodegradation in the higher plants, these products are partially or totally decomposed in the plant during a suitable period, thanks to which it is not necessary to eliminate later. On the other hand, they are incorporated into the natural circuit of degradation of substances. Compared to traditional systems, these represent a particular advantage, because these systems do not constitute a burden on the environment. The bodies according to the invention can be biodegradable in an active microbial environment either partially or totally (ie in water, carbon dioxide and the products of the natural metabolism). The biological degradation capacity refers first to the polymers, which are applied as carrier materials in the case of the implants according to the invention. Here the bioactive compounds are introduced into an inert polymer matrix, without being chemically bound. Polymers are applied which, on the one hand, have a high capacity for capturing the active substances (carrying capacity) and, on the other hand, have an adequate functionality (sufficient mechanical stability as well as a processing capacity), are not phytotoxic, and can mix in wide ranges with other substances.

Here it is imperative that the polymer matrix contain a hydrophobic polymer. Suitable hydrophobic, biodegradable polymers include the following classes of materials: aliphatic polyesters such as caprolactone, poly-3-hydroxybutyric acid, copolymers of polyhydroxybutyric acid / hydroxylaleric acid and polylactic acid; cellulose derivatives with a degree of substitution < . 2 such as cellulose ether, cellulose ester or mixtures of esters; the polyanhydrides; Chitin As for example of an aliphatic polyester, there can be mentioned a polyhydric acid 3-hydroxybutyric acid / 3-hydroxyvaleric acid with a molecular weight of 450,000. As an example of a cellulose ether, cellulose diethyl ether can be mentioned. As an example of cellulose esters, cellulose diacetate can be mentioned as mixtures of cellulose acetate-butyrate esters. As an example of the polyanhydrides, the poly (1) copolymer can be mentioned., 3-bis-p-carboxy-phenoxy-propane / sebacic acid. All the hydrophobic polymers proposed here are largely biodegradable and can be processed thermoplastically, they are problems. The main advantage of the shaped bodies, according to the invention, in comparison with all the implanted systems that siministra the active principle according to the technique, resides in the fact that with the incorporation of the hydrophobic polymers in their carrier matrices of active principle, it is possible to achieve an incorporation of strongly lipophilic active principles, free of problems, as well as achieve a delayed release of the active principle. It is a known fact that the hydrophilic properties are of great importance in implants containing active principles, because they ensure a bioerosion based on the expansion and / or hydrolysis, and with it a rapid release resulting from the active principle. On the contrary, the hydrophilic character of such systems is from the point of view of the incorporation of bioactive substances, strongly lipophilic, rather undesired. Through the use of hydrophobic polymers, which operate as a communicating phase in the dispersion of the active ingredients, a relatively homogeneous distribution of the substances incorporated is achieved. From the bodies formed, according to the invention, the active ingredients are deposited after their implantation in the plant organism. The release of the active ingredients can be done through their diffusion and / or expansion or bioerosion of the implanted bodies.

In view of the fact that the expansion capacity and the bioerosion capacity are positively influenced by the hydrophilic properties by the polymers (activation) the incorporation of a hydrophobic base in a composition of a polymer, produces an extension of the residence time of a manufactured implant from it, in the plant and consequently, a delay in the release of the active principle. Thus, it is possible to apply the formed bodies, according to the invention, (depending on the proportion of the hydrophobic polymers) in a release of the slowest and most durable active substance. A particular advantage of the bodies formed, according to the invention, consists in the fact that the molding materials used for their manufacture show easy processability in thermoplastic form. This improvement in processability concerns primarily the fluidity and the viscoelastic behavior of the dough. In particular, if a polymer composition is present, constituted of two immiscible phases, where the incorporation of plasticizing agents is required to achieve a good mixing of the phases, the improved processability of the mass is caused through the incorporation of the polymers. hydrophobic, it remains manifest. A preferred embodiment of the bodies formed according to the invention has the following components! 0.5 to 90% by weight of at least one polymer, wherein the proportion of a hydrophobic polymer amounts to at least 30 to 80% by weight, preferably 50 to 65% by weight, of the polymer content. The relationship between the material of the matrix (polymer) and the auxiliary substances, which together form a system carrying the active principle of the body formed according to the invention, can be varied over wide ranges. A large number of polymers can be used as biodegradable carrier materials. The polymers of glycolic acid and lactic acid are suitable, as well as their copolymers (in different weight ratios of the monomer units). Particularly suitable are the aforementioned carbonic acid derivatives, such as polylactides, polysiloxanes and their copolymers. In general, homopolymers and copolymers of the acids to lfa-hydroxygrases with 2 to 16 carbon atoms and their derivatives are suitable, insofar as these are absorbable in the plant organism, such as, for example, acid to lfa -hydroxybutanoc, lfa-hydroxy isova leric acid, lfa-hydro i isocaproic acid, lfa-hydroxyheptanic acid, lfa-hydroxyocanic acid, lfa-hydroxydecanoic acid and lfa-hydroxymyric acid. Among the derivatives of the acids to lfa-hydroxyfathers, particular mention may be made of the polyhydroxyvalerate and the polyhydroxybutyrate, as well as their copolymers. According to the invention, the biodegradable implants can also contain polymers of natural origin as carriers of the active principle. Among these, starch, Kraft lignin, chitin, cellulose and their derivatives can be mentioned as particularly suitable. As hydrophobic components of the polymeric matrix of the bodies formed according to the invention, different biodegradable polymers can be applied. Illustrative examples are the following: aliphatic polyesters, for example caprolactone, cellulose derivatives with a degree of substitution < 2, for example, cellulose diethyl ether, polyanhydrides, for example, the poly (1, 3- (p-carboxy-phenoxypropane / -acid is bacillic) copolymer. Among the active ingredients that can be administered to plants by the bodies formed, we can mention those substances that allow to influence the processes in the animal or vegetal organism, among which we can mention first the phytosanitary agents of systemic action (insecticides, acaricides, fungicides and bactericides) .The systemic insecticides are for Examples are Buthocarboxim, Dimethoate, Phenoxycarb, Methamyl, Oxamyl, Oxydemteton-methyl, Pirimicarb or Propoxur.The systemic acaricides are, for example, Clofentizine, Fenbutathione-Oxide and Hexithiazox Systemic fungicides are, for example, Benomyl, Bromuconazole, Bitertanol, Etaconazol, Flusilazol, Furalaxil, Fosetyl-Al, Imazalil, Metalaxyl, Penconazol, Propioconazole, Thiabendazole, Triadimefon, Triadimenol or Triforine. Among the systemic bactericides are for example the Flumenquine Regulators of systemic growth are for example Etephon and beta-indolyl acetic acid (ES). As is known, these systemic active principles can be absorbed by the organs of the plant (the leaves and the roots, the growth axis), after the application of the conventional preparations and after the resorption, they are transported in the system of driving the plant and be distributed systemically. Other bioactive substances, whose administration is possible with the aid of the bodies formed according to the invention, are the fortifying products of the plants, such as the plant extracts of the nettle, craving, horsetail or the spigot, which they can have a local or also systemic effect. The principles can be present in the bodies formed alone or in mixtures between them. They can be dissolved or dispersed in the polymer matrix Also from the point of view of the particle size of the active principles incorporated in the framework of the present invention, numerous possibilities of variation are presented. As a preferred particle size, the range of less than 10 microns can be mentioned.

The function of the auxiliary substances consists in offering the active principle to the plant in an adequate physical-chemical form, so that it is available for the desired therapeutic purpose. On the other hand, these substances lead the active principle to optimally develop its implied potency. As auxiliary agents, the bodies formed according to the invention may contain penetration promoters, accelerators of degradation, pore formers, pH regulators, emulsifiers, fillers, plasticizers. By means of the penetration promoters, the absorption of the biological substance in the plant's conduction system is reinforced. For this purpose, for example, alkyl sulphates, alkyl sulfonates, fatty acids, fatty acid salts of polyvalent metals, fatty acid esters, amine oxides, mono-, di-, or triglycerides, long chain, salicylic acid, 2-pyrrolidone derivatives, or urea. The accelerators of degradation are those substances that accelerate the rate of degradation of the implant. Suitable substances that can be incorporated as accelerators of the degradation to the formed body, according to the invention, are for example acetic acid esters such as methyl-, ethyl-, n-propyl-, isopropyl-, n-butyl-, iso-butyl-, n-pentyl-, and isopentyl-ester. In particular, the ethyl ester of acetic acid, which is also called acetic ester, is preferred. Apart from the compounds that influence the rate of degradation of the carrier material, the implants according to the invention also contain substances in the form of pore producers, which allow a control of the release of the active principle. Through the system of pores formed in the body with the help of the pore former, the active principle is capable of diffusing directly, or the process of bioerosion is initiated, or it is accelerated. Suitable pore formers are, for example, onosaccharides and water-soluble disaccharides, such as glucose, fructose, xylose, galactose, sucrose, maltose, sucrose, and related compounds, such as mannitol and sorbitol. Particularly preferred is lactose. The pH regulators suitable in the present invention are glycerin, citrate, borate, phosphate-type pH regulators or citric acid. Suitable emulsifiers are, for example, higher fatty alcohols, partial fatty acid esters, polyfunctional alcohols, partial fatty acid esters of sugars, fatty acid esters of polyethylene glycol., the fatty acid esters of polyethylene glycol sorbitan, as well as the phospholipids, the quaternary ammonium compounds and the pyridinium compounds. As fillers, aluminum oxide, zinc oxide, titanium oxide, and silicon dioxide can be applied. With the aid of the plasticizing agents, the preparation of the formed masses is facilitated, especially during the phase of the mixing of the phases and the forming step. Suitable plasticizers are, for example, poly (ethylene glycol) phenyl ester (Pycal 94), glycerin, sorbitol, palmitinic acid, lauric acid, and the oleic acid derivatives. The quantitative and qualitative combination of the polymers and the formulation auxiliaries, which as a whole represent a carrier system for the active principle, is decisive for the release of the active principle, an aspect that the specialist can take advantage of for adjusting the desired release speed. The preferred variants of the formed bodies, according to the invention, are constructed on the basis of absorbent substances in stepped form. According to a particular embodiment of the invention, the carrier matrix of the bodies formed represents a combination of biodegradable polymers with differentiated molecular weights. Through the degradation of the polymers with a lower molecular weight, a previous release of the active principle occurs, whereas with the delayed degradation of the polymers with a high molecular weight, the release occurs at a later time. As low molecular weight polymers, the implants according to the invention can carry, for example, poly- (L-lactic acid), poly- (D-lactic acid), poly- (DL-lactic acid), polyglycolic acid and the copolymers of the compounds mentioned above. The molecular weights of these compounds are comprised between 1000 to 4000, preferably 1500 to 2500. Another preferred embodiment of the compounds formed of the invention, are the implants provided with an additional coating of a low molecular weight polymer, which does not contain active substance. This avoids a rapid release of the active principle after the implant is made in the initial phase. It is also possible to regulate adequately, by incorporating suitable biologically inactive groups, such as, for example, the organometallic compounds in the carrier system of the active principle, the rate of degradation of the implant and thereby the rate of release of the active principle. Particularly advantageous are the bodies formed according to the invention on the basis of polyesters. In these it is possible to indirectly control their rate of degradation through the number of ester-type bonds. It is a known fact that the carboxylic groups formed after the enzymatic or hydrotic degradation of the esters, the hydrophilic character of the copolymers of the matrix and with them their capacity of expansion in the physiological medium of the plant. By the targeted application of the polyesters with a known chemical structure and with known physical parameters, the person skilled in the art can determine the degradation time of the formed body until its complete solubilization in an anticipated manner and suitable to the particular desired use. The physical combinations of the active principle / carrier / auxiliary agent, represented by the body formed according to the invention, form a rather hard joint, mechanically stable, but at the same time deformable. This union can be made to different different three-dimensional structures. All embodiments may have a multilayer structure, wherein at least one of the layers of the laminate contains a systemic active principle. The different layers of the attached structure can be dependent on each other or coherent, but it can also be subdivided into segments (compartments 1, in Figures 1 to 3). The variation of the arrangement of the compartments with each other is not limited. They can be constructed with a "core" type construction, where one of the layers of the laminate is surrounded by the layer located higher or lower, or they can be enclosed, forming in this way the nucleus (see Figure 1). As another arrangement of the segment, an alternate layer arrangement is possible (see Figures 2 and 3). By combining several compartments it is possible to combine simple active principles and obtain segments with different concentrations of differentiated active principles. Individual compartments can vary greatly in the rate of release of the active ingredient. It is not essential that all compartments contain active ingredients. Thanks to the use of compartments with a differentiated release profile, it is also possible to administer different active ingredients in a predetermined order in time with a single implant, an aspect that is particularly advantageous, for example, in differentiated therapies, but of diseases that occur in an associated way in plants. The implants according to the invention can be obtained in the form of pieces formed with a differentiated geometry. As shaped parts, rods, plates, spheres of different sizes, and granules are preferred. The pieces of pieces have been conveniently sized in such a way that they can be easily handled manually. In general, the particle size is from 0.1 to 50 mm, preferably from 0.2 to 20 mm. Between the suitable modalities the forms of a nail and a screw of special way can be emphasized, since these forms are favorable of the application and of m uy easy handling. A particularly suitable shaped body is shown in the form of a nail (Figure 4), the tip of which has a strong mechanical configuration. The mechanical strength can be achieved, for example, by a coating of a hard metal, for example, a metal coating. This embodiment is particularly advantageous because it avoids the use of special implant devices, allowing the implant to be placed by a non-specialist person. Another advantage of this embodiment is that the hollow space formed during application in the trunk of the plant is hermetically sealed by the nail head. This avoids the potential risk of the release of the active principle. Another particularly advantageous embodiment of the implants of the invention is a device in which there are several pieces of nail type, 5, connected to each other, where the pieces are fixed on or inside a rigid plate 4 (Figure 5). Depending on the number of implants that are to be applied, the plate can have different dimensions. The plate consists of a mechanically resistant material, attractive to the tissue of the plant. Among the particularly suitable materials, wood can be mentioned here. The particular advantage of this method is that the incorporation of the bodies in the lignified trunk of the plant is considerably facilitated. This embodiment is particularly advantageous in that several nail-shaped bodies are gathered, which, thanks to their small dimensions, are difficult to handle individually, being assembled into a single application unit. On the other hand, the force of the blow distributes in a relatively uniform form to the individual components, reducing to the minimum the danger of damaging the tissues as a consequence of a too accentuated mechanical action. The formed bodies of the invention can be made in plastic form and thus are suitable for manufacturing according to different methods, such as, for example, extrusion, compression and molten injection. The bodies formed according to the invention, they can be used advantageously to administer the bioactive substances to the plants. The active principles can be, in general, phytosanitary agents (insecticides, fungicides, bactericides, acaricides), fortifying agents of plants and growth regulating substances (phytohormones, fertilizers). The incorporated administration systems are preferably applied when a conventional application technique is not possible, or said technique is not reliable or does not make sense. A special field of application is the urban parks, where the protective measures of the plants can hardly be applied in the case of trees by conventional techniques. These biodegradable implants are particularly suitable for the long-term treatment of plants, in particular of trees, for example, fruit trees and in forestry, where certain diseases occur regularly and in certain seasons of the year. The bodies formed according to the invention are implanted in the growth axis of the plant, where the preferred implant site is the axis of growth development. Particularly suitable are the implants applied in those plants that have lignified shoots (bushes and trees). The invention will be further applied through the following examples.

EXAMPLE 1 60 g of poly-3-hydroxybutyric acid (PH B) and 40 g of polyvinyl acetate were dissolved in 20 g of chloroform. The solution was carefully evaporated at a temperature of 30 ° C, and dried in vacuo. The uniform mass thus obtained was pulverized in a hammer mill and then heated with the incorporation of 6 g of polyethylene glycol 400 (PEG 400) and 10 g of Posety-AI in a suitable device, for example in an extruder for thermoplastic minerals , until a temperature of 180 ° C, until having obtained a deformable mass. The active substance Fosetyl-A 1 is dispersed homogeneously in the softened polymer by kneading. The suspension of the active principle / polymer obtained in this way is then injected through a nozzle with a suitable diameter (> 2 mm). The strand or strip thus obtained is subdivided into aggregates in the form of rods, whose content of active agent is determined by its dimensions.

EXAMPLE 2 The commercially available fleece of chitin fibers was pulverized in a ball mill and 375 g of this powder were treated with 25 g of a copolymer consisting of 75 mol% of lactide and 25 mol% of glycolide and 20 g of Triticonazole . The mixture thus obtained is well homogenized. It is then pressed in a heated press at a temperature of 135 ° C under a pressure of about 630 bars for 2 minutes, delivering negative pieces in the form of nails in a metal matrix; each of the formed bodies contains 89.2% by weight of polymer, 6.0% by weight of copolymer and 4.5% by weight of thiabendazole.

EXAMPLE 3 A mixture formed of 64% > by weight of poly-epsilon-caprolactone, 22% by weight of poly-lactic acid, 4% by weight of glycerin and 10% by weight of the active ingredient Fosetyl-A1, was melted in an extruder at a temperature of 120 to 145 °. C and then expanded into a spreading box forming a film with a thickness of 2000 microns. Once cooled, the film was cut into rod-like pieces. Finally, the pieces obtained by rollers are formed. In order to further explain the invention, Figures 1 to 5 will now be described.

BRIEF DESCRIPTION OF THE DRAWINGS In Figure 1 there is shown a formed body constituted by several compartments (segment) 1, where one compartment is surrounded by the next. Figures 2 and 3 show a formed body, in which the individual segments are arranged alternately, in the embodiment of Figure 2, the individual compartments contain different active ingredients, separated from each other. In the embodiment of Figure 3, one compartment contains two or several different active ingredients. Figure 4 shows a shaped, nail-shaped body with a hardened tip 2 and other compartments 3. Figure 5 shows a special embodiment, in which several bodies in the shape of nails 5 have been assembled in an application unit, being fixed on the rigid plate 4.

Claims (1)

1. - An implantable molded body, partial and biologically degradable polymer, to administer active plants substances, comprising at least one hydrophobic polymer, the polymers being biodegradable and the active substance release being controlled by the biodegradation rate, and comprising the following components, in relation to the total weight of the molded body: a) from 0.5 to 90% by weight of at least one polymer, the proportion of the hydrophobic polymer representing at least 30 to 80% by weight, preferably 50 to 65% by weight, b) from 0.5 to 15% by weight of at least one active ingredient, c) from 0.0 to 50% by weight of formulation aids, characterized in that it is present in the form of a nail, the tip of which (2) is made mechanically resistant, and the trunk as well as the head includes compartments (3) of which at least 1 comprises the active principle. 2 - The molded bodies according to the claim 1, where there are different kinetics of the active principle, in different compartments. 3 - The moldings according to claim 1 or 2, wherein they are formed as a device having several nail-like members (5), which are connected to each other by means of a support (4). 4. The molded bodies according to claim 2 or 3 wherein the biodegradable polymers are selected from the group consisting of poly-lactic acid, polyglycolic acid, polylactides, and copolymers thereof, all of the homo- and copolymers of alpha-hydroxy fatty acids having from 2 to 16 carbon atoms, as well as their derivatives, polyamides, polyorthoesters, polyanhydrides, starch, lignin, chitin, cellulose and their derivatives. 5. The molded bodies according to claim 2 or 3 wherein at least one of the following polymers is used as the hydrophobic polymer: an aliphatic polyester such as polycaprolactone, polihidroxibutanoico acid copolymer polihidroxibutanoico acid / hydroxyvaleric acid , and / or poly-lactic acid, a cellulose derivative with a degree of substitution of < 2, such as a cellulose ether, a cellulose ester, or a mixed ester of cellulose acetate / butyrate, chitin, lignin from the Kraft process, polyanhydrides. 6. The shaped bodies according to one or more of claims 1 to 5, wherein it comprises at least one active ingredient of the following groups: insecticides: Buthocarboxim, Dimethoato, Fenoxycarb, Methamyl, Oxamyl, Oxydemteton-methyl, pirimicarb or Propoxur; fungicides: Benomyl, Bromuconazole, Bitertanol, Etaconazole, Flusilazol, Furalaxil, Fosetyl-AI, Imazalil, Metalaxyl, Penconazol, Propioconazole, Thiabendazole, Triadimefon, Triadimenol, Triforine; Bactericides: Flumenquine; acaricides: Clofentizine, Fenbutation-oxide and Hexithiazox; Regulators of growth: Etephon and beta-indolyl acetic acid (ES) 7 '.- The use of a molded body according to one or more of the preceding claims as an implant, which is incorporated into the body of a plant for the administration of active ingredients to the plant. 8. The use of a molded body according to claim 7, for implantation, preferably on the growth axis of the plant, and most preferably on the plant sprout base.