[Biopharmaceutical and clinico-pharmacological research on the intramammary preparation Cephamasten].

An animal drug formula, Cephamasten, for intramammary application in the treatment of mastitis-affected cows, ewes, and goats in the lactation period was worked out on the base of microbiologic, technologic, biopharmaceutic, and clinico-pharmacologic studies. Its active ingredient was the Pharmachim cephalexin-monohydrate. The consistence of Cephamasten has proved suitable for intracisternal introduction.

[Preclinical research on drug forms containing rifamycin SV intended for intramammary use].

It was established, that LD50 of rifamycin SV--sodium salt, produced by the Research Institute on Microbiological Industry--Razgrad (People's Republic of Bulgaria)--RM, at p.o. applying on albino mice, albino rats and broilers is correspondingly greater than 4100.

[Postgraduate training in veterinary pharmacology].

The system of postgraduate training of veterinary pharmacology in the European countries is different--in some countries it is connected mainly with the intensive research work and with the obtaining of academic ranks (Ph. D., Dr.

[Efficient drug forms and the means for using them in the intensive raising of animals].

Stated is the use of promising therapeutic formulae that produce prophylactic, metaphylactic, and curative effects at lower input of labour and handling, inciting lower unrest with animals, belonging chiefly to the type of the so-called 'therapeutic systems'. Particular attention is paid to drugs for programmed, continuous, and checkable release of the active ingredients in compliance with what is needed at the time (sustained release forms)-type OROS (oral osmotic system), type 'liquid reservoir', type 'glass cylinders', tablets and boluses of higher relative weight, or multilayer and mosaic ones for ruminant animals (with extendable wings, inflatable and flowing ones of the float type), and some of them for monogastric animals. Beside the boluses for the forestomach of ruminants there are the hollow bridle for horses, the ear swabs (for resorptive application), the ocular (ocusert), nasal, and vaginal forms (for resorptive therapeutic use), the skin transmembrane therapeutic systems (TTS), the pourable (pour-on and spot-on) forms, 'autodas' osmotic mini-pumps, the depot-forms, the implants, the aerosol (inhalational) forms, the 'ear rings' (ear tags) as well as the dewlaps, the rings (for tails, limbs, and ears) and the medicated feeds and liquids, and the intramammary, intrauterine, and other therapeutic forms.

[Pharmacokinetics of amoxicillin trihydrate in sheep infected experimentally with Corynebacterium pyogenes and Escherichia coli].

A comparative experiment was carried out with sheep that were infected i/v and via the joints with Corynebacterium pyogenes and Escherichia coli, and with normal sheep left as controls. The pharmacokinetic parameters were determined of amoxicillin-trihydrate following its i/m application to all animals in a 20 percent oil suspension. It was found that there was delayed excretion of the antibiotic, and as a rule it was maintained in higher concentrations in the diseased animals.

[Ergotrophic action of flavophospholipol during the fattening of geese].

Experiments were carried out with a total of 144 geese of the Benkovska breed divided into 6 groups of 24 birds each. The average weight was 3.5 kg, the birds being compulsory fattened with steamed maize over an average period of 27 days.

[Pharmacokinetics, biological availability and residues of sulfadoxine and trimethoprim when used jointly on calves].

In calves (cross-breds--Bulgarian Brown Cattle breed and Black Spot Cattle bred) weighing about 189 kg pharmacokinetics of sulphadoxine (SD) and trimethoprim (TMP) was studied. The two substances were administered in combination (5 + 1) as a dosage form Tridoxin (Pharmachim, Bulgaria; 24% injectable solution) (TD) at a dose 15 mg/kg m. The results show that after intramuscular administration TD is absorbed relatively rapidly.

[Blood amoxicillin concentrations in agricultural animals and poultry treated intramuscularly with drug forms containing amoxicillin sodium and amoxicillin trihydrate].

The sodium salts of ampicillin and amoxicillin at the single i/m application in 20 per cent water solutions at the rate of 10 mg per kg of body mass guaranteed close therapeutic concentrations of both antibiotics in the blood serum of birds and rabbits. Amoxicillin-trihydrate in a 20% water suspension applied i/m in a single dose of 10 mg/kg persisted in a therapeutic concentrations in the blood serum of birds for a longer time (10 hours) than ampicillin-trihydrate (8 hours). The oil suspension containing 20% amoxicillin-trihydrate guaranteed bacteriostatic serum concentrations in the course of 24 to 48 hours at single i/m application in doses of 20 and 30 mg/kg, depending on the amount and the species of animal.

[Pharmacological, toxicological, microbiological and pathohistological studies of gentamycin complex II].

The acute toxicity was determined of the gentamycin complex II (GMC-II) for albino mice, containing gentamycin components in a varying ratio. The LD50 at intraperitoneal application was 347.7 mg/kg body mass, while at oral application it was 5,180 mg (4933 divided by 5439) mg/kg body mass.

[Trial of trimedin action on chickens].

Investigations were carried out with a total of 421 broiler birds (four-line Cornish X Plymouth Rock hydbrids) within the age range of 2 days to 5 weeks. Determined was the acute toxicity of the combination sulfadimidine (SDM) + trimetoprim (TMP)--5 + 1 and the water-soluble formula of trimedin following the intraingluvial introduction with week-old birds. LD50 of the combinations SDM+TMP (5+1) was 3980 mg/kg (2780: 5690), and that of trimedin was 2038 mg/kg body mass.

[Doxycycline hydrochloride administered in the drinking water to poultry].

Investigated were the acute toxicity, serum concentrations, and residual amounts of doxycycline in broiler chickens. It was found that the LD50 of doxycycline when applied via the crop to week-old broiler birds was 2500 mg/kg mass. The amount of 0.

[Tridoxin toxicity and tolerance in agricultural animals].

It was found that LD50 of tridoxin (sulfadoxin-trimetoprim-5 + 1--State Economic Corporation Pharmachim) at i/m application to albino mica was 950 mg/kg, and of borgal (Hochst)--920 mg/kg. At oral application these values were 2650 and 2660 mg/kg, respectively. LD50 of tridoxin at i/m application to albino rats was 1075 mg/kg, and of borgal--1320 mg/kg; orally, these values were 3000 and 3260 mg/kg, respectively.

[Intramammary drug forms of neotil in treating mastitis during lactation].

Technological, biopharmaceutical, and clinico-pharmacological studies were carried out on the varying composition of drug formulas that included a tylosin base and neomycin sulfate, intended for the treatment of mastitis-affected cows during the lactation period. A base was developed of suitable viscosity and physico-chemical properties, that rapidly released the active ingredients included in it and made them penetrate in depth in the udder glandular tissue. Both the base and the drug formula Neotil were shown to be well tolerated.

[Effect of salinomycin (K 364) on the fattening of pigs].

Experiments with pigs of the White Bulgarian Improved breed of initial weight of 25 kg revealed that the oral administration of salinomycin at the rate of 50 ppm (from the beginning of treatment up to the 61st day) and 25 ppm (from the 62nd day up to the 117th day) with the feed led to the increase in weight gain by 10.9 per cent and in feed conversion by 7.4 per cent by the end of the experimental period.

[Effect of salinomycin on lambs for fattening].

When applied to male Trakiiska tunkorounna lambs of initial weight 18.6 kg in the course of 90 days at concentrations of 6 g, 12 g, and 24 g per ton of forage slinomycin brought about a rise of liveweight and average weight gain in the treated animals (for the weight gain 12.2, 16.

[Current animal feeds with antimicrobial activity].

Among the growth-promoting substances and factors contributing to fodder utilization in growing farm animals, also called nutritive, ergotropic means, the antibiotics and some synthetic chemotherapeutics have acquired special importance. To avoid the hazardous effect in humans consuming products of animal origin there should be no residual amounts of these stimulating agents in such products. That is why it has been assumed in a number of countries to use for the same purpose only nutritive means that are not applied as therapeutic agents.

[Effect of salinomycin (K-364) on calves for fattening].

Experiments with calves of initial weight of about 178 kg revealed that salimycin given with the feed at the rate of 0.5 mg/kg for 24 hours in the course of 269 days, and monensin used for comparison at 0.7 mg/kg for 24 hours led to the increase in the weight gain by 4.

[Toxicological studies of Bulgarian activated bentonite].

We studied the endurance of calves, lambs and pigs as well as the acute, subchronic and chronic toxicity for chickens with regard to bentonite of local origin, extra activated in a physico-chemical way. It was proved that the medicine was rather endurable with calves, lambs and pigs without causing intoxication or death after a single internal introduction in doses respectively 4138, 4130 and 1860 mg/kg t. LD0 of the activated bentonite for the chickens in the case of intra-crop application was over 18000 mg/kg t.

[Blood concentrations of sulfadimidine after the internal use of depot sulfadimezine granules in sheep].

A granular premixed form, called sulphadimesin-depot-granules, was produced, containing 40% of sulphadimine inserted into a hydrophobic matrix of hydrogeneric sunflower oil. After a single internal insertion into sheep by means of a stomach-tube or of a bottle on an empty stomach in a dose of 0.5 g/kg t, they caused bacteriostatic concentrations in blood plasma during 78 hours, and in a dose of 1.

[Toxicity of hydroxyquinoline derivatives].

We studied a 90 day toxicity in dogs of the compound broxyquinoline + broxaldine--5:1 (enteroquin), applied orally and daily in doses of 0.1 and 0.2/kg t/24 h.

[Immunosuppressive activity of several drugs and their effect on antibody formation in pullorum disease].

Furazolidon given alone or in combination with chloramphenicol, with spectinomycin, with gentamycin or with sodium arsenilate as well as chlorpyrazine, applied alone, suppress the clinical manifestation of pullorum disease in birds both in the experimental and in the spontaneous outbreak of the disease. These medicinal drugs lower the production of agglutinins in birds--mostly the combination furazolidon+chloramphenicol, followed by furazolidon+sodium arsenilate. The same combinations do not prove essentially effective in influencing the development of the morphologic lesions and do not fully exempt the body from the causative agent of pullorum disease.

[Effectiveness of sodium arsamilate and its effect on the immunity of hens experimentally infected with Borrelia anserina].

The toxicity of sodium arsanilate for chickens was determined following a six-day oral application. Doses higher than 0.15/kg body weight led to symptoms of intoxication and death, especially when the intake of water was restricted.

[Nutritive action of flavophospholipol and virginiamycin on broiler pullets].

Studied were some of the aspects of the antibiotic treatment with flavophospholipol (moenomycin) as the preparation flavomycin, and virginiamycin (staphylomycin) as the preparation escalin in a premix form as an animal formula. It was found that the antibiotics tested acted as nutrients: they had a positive effect on the growth and feed conversion. They raised the production of meat and improved the quality of the meat product in terms of higher protein and mineral contents.

[Possible synergic action of some drug combinations against Mycoplasma gallisepticum].

Yamamoto and Adler's method (1956), making use of the modified medium of Edward, was employed to determine the minimal concentrations of gentamicin (GMC), erytrhomycin (ERM), oleandomycin (OMC) spectinomycin (SPM), tetracycline (TC), tylosin (TLS), and chloramphenicol (CA), all of them showing bactericidal effects on Mycoplasma gallisepticum-S6, applied alone or in combination. In vitro studies showed that relatively most effective were TLS, GMC, and SPM, when used alone. Combining the antibiotics by two in the most cases led to a pronounced synergic effect.