In de onbestreden Engelse vertaling van de beschrijving van EP 496 is voorts - voor zover hier van belang - het volgende opgenomen:
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[0001]
The invention relates to formulations containing triazinones and iron compounds (salts and complex compounds of iron) which are suitable for the simultaneous control of coccidioses and anaemic states in animals.
[0002]
Economically successful meat production operations are currently distinguished by
highly intensive farming, that is to say by the keeping of a large number of animals which are specifically selected in order to optimize the breeding aim. These farms are characterized for example by the use of a great deal of machinery, the additional feeding of food supplements, and the involvement of as little staff as possible. In the case of piglet rearing farms, this means that a large number of sows which are bred for a high number of piglets per litter are kept in suitably large pig houses. The optimization of the feed, and suitable selection in the breeding process, make it possible for the piglets to grow rapidly.
[0003]
This type of animal keeping is frequently the cause for an increasing number of certain typical diseases and deficiencies. Besides stress, to which in particular intensively kept pigs are very susceptible, such phenomena are, in young pigs, protozoal infections (coccidioses) and anaemic states, inter alia, both of which already have to be kept under control by the prophylactic use of medicaments.
[0004]
Coccidioses are frequently occurring, parasitic infectious diseases in animals. (…)
[0005]
An example of a deficiency is iron deficiency in newly-bom piglets. Owing to the rapid growth in the first days after birth, the body’s iron reserves are rapidly depleted and must be compensated for by external sources. Because of the large number of suckling pigs, this substitution by taking up the sow’s milk cannot take place in a sufficient degree. If, moreover, the animals are kept on concrete or plastic, the piglets cannot take up iron compounds by rooting in the ground either. The piglets become anaemic. A clinically significant anaemic state exists when the haemoglobin content of the blood has dropped to less than 80 g/l. The NRC recommendation (National Research Council, Nutrient Requirements of Domestic Animals, No. 2, Nutrient Requirements of Swine, National Academy of Sciences, Washington DC, 1973) specifies 90 g/l as the minimum haemoglobin value at which the piglets grow healthily and show no signs of anaemia. (…)
[0006]
Preparations are already available for controlling the abovementioned diseases and deficiencies.
[0007]
Coccidiosis can be controlled successfully by administering active ingredients from the triazinone group. To this end, one distinguishes between the triazinediones - with examples of representatives being the active ingredients clazuril, diclazuril, letrazuril - and the triazinetriones with the active ingredients toltrazuril, toltrazuril sulphoxide and ponazuril. (…)
(…)
[0011]
(…) Toltrazuril is available on the market for example as a drinking water formulation for poultry and as an oral suspension formulation for, inter alia, the treatment of suckling pigs. It is recommended to administer, to the piglet, a dose of 20 mg/kg bodyweight on day 3-5 after birth.
(…)
[0013]
A series of quite different iron preparations, which differ both in the type of compound and in the mode of application and bioavailability, are available for preventing iron deficiency anaemia. One distinguishes between (I) simple inorganic Fe(2+) salts, (IIa) complex compounds of Fe(2+) with organic ligands, for example with lactic acid, or (IIb) of Fe(3+), for example with citric acid, and (III) polymer-type complex compounds of an Fe(3+) oxo-hydroxo complex β-FeO(OH) of the akaganeite type with carbohydrates/polysaccharides, specifically with oligomeric or polymeric carbohydrate compounds, such as, for example, with dextran or with dextrin/polymaltose. (…)
(…)
[0019]
These considerations have given rise to the doctrine that Fe(3+) compounds in general, and in particular polynuclear compounds such as iron(III) dextran, are not suitable for oral application (…).
[0020]
A further reason for being reluctant to use polynuclear Fe(3+) complexes, in particular iron(III) dextran, orally is the specific uptake pathway of B-FeO(OH) complexes in the intestinal tract. (…) However, it is also known that this transit of high-molecular-weight compounds from the cells of the mucosa into the lymphatic system and bloodstream of the piglets is only possible without hindrance immediately after birth. This mechanism ensures that the piglets can be supplied with immunoglobulins and antibodies immediately after birth by taking up the sow’s colostrum. As soon as this supply is ensured, the transport mechanism becomes defunct. This “intestinal closure” during the further course of growth is biologically meaningful in order to avoid infections with microorganisms and toxins (…) Since, however, current keeping conditions at the breeders’ naturally allow suckling, it is current knowledge and generally medically acknowledged that a sufficient supply of piglets with high-molecular-weight iron complexes via the oral route is only possible, in a meaningful manner, in the first hours after birth if multiple applications are to be avoided. Those few authors who have systematically studied the efficacy of iron(III) dextran as a function of the timing of the oral application report on a substantially reduced activity when the iron(III) dextran is administered 24-72 h after birth (…) Depending on the keeping and feeding conditions, however, an administration on day 2 of life will still give sufficiently good results (…) In contrast, when administering the iron dextran 72-96 h after birth, the efficacy is already greatly reduced (…) Even with these preparations, however, the manufacturer recommends that they be used up to no more than 8-10 h after birth in order to achieve an optimal effect. This, in turn, requires the continuous monitoring of the breeding sows, which means a great deal of labour.
(…)
[0022]
To circumvent the above-described imponderabilities in the case of oral application, it is more conventional in pig rearing to administer polynuclear iron(III) complexes intramuscularly by means of an injection. (…)”