EP1014970A1 - Parasiticidal formulations - Google Patents

Parasiticidal formulations

Info

Publication number
EP1014970A1
EP1014970A1 EP98951367A EP98951367A EP1014970A1 EP 1014970 A1 EP1014970 A1 EP 1014970A1 EP 98951367 A EP98951367 A EP 98951367A EP 98951367 A EP98951367 A EP 98951367A EP 1014970 A1 EP1014970 A1 EP 1014970A1
Authority
EP
European Patent Office
Prior art keywords
implant
parasiticidal compound
parasiticidal
tabletting excipients
implants
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP98951367A
Other languages
German (de)
French (fr)
Inventor
Hiep Pfizer Central Research HUATAN
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Pfizer Ltd
Pfizer Inc
Original Assignee
Pfizer Ltd
Pfizer Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from GBGB9720228.7A external-priority patent/GB9720228D0/en
Priority claimed from GBGB9810143.9A external-priority patent/GB9810143D0/en
Application filed by Pfizer Ltd, Pfizer Inc filed Critical Pfizer Ltd
Publication of EP1014970A1 publication Critical patent/EP1014970A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K9/00—Medicinal preparations characterised by special physical form
    • A61K9/0012—Galenical forms characterised by the site of application
    • A61K9/0019—Injectable compositions; Intramuscular, intravenous, arterial, subcutaneous administration; Compositions to be administered through the skin in an invasive manner
    • A61K9/0024—Solid, semi-solid or solidifying implants, which are implanted or injected in body tissue
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P33/00—Antiparasitic agents
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
    • A61P43/00—Drugs for specific purposes, not provided for in groups A61P1/00-A61P41/00
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K9/00—Medicinal preparations characterised by special physical form
    • A61K9/20—Pills, tablets, discs, rods
    • A61K9/2004—Excipients; Inactive ingredients
    • A61K9/2013—Organic compounds, e.g. phospholipids, fats
    • A61K9/2018—Sugars, or sugar alcohols, e.g. lactose, mannitol; Derivatives thereof, e.g. polysorbates

Definitions

  • This invention relates to a solid implant containing a parasiticidal compound having low aqueous solubility, which is particularly useful for administration to livestock such as cattle, pigs and sheep.
  • a number of potent macrocyclic parasiticidal compounds are known, including the avermectins and milbemycins.
  • UK Patent N° 1,573,955 discloses a family of avermectin compounds (including avermectins Bla and Bib) which are indicated as parasiticides.
  • 22,23-Dihydroavermectin Bl (ivermectin, disclosed in EP 1689) is available commercially in an injectable formulation (sold as IVOMECTM).
  • Ivermectin is a mixture of at least 80% 22,23 -dihydroavermectin Bla (having a 25-sec butyl group) and not more than 20% of 22,23 -dihydroavermectin Bib (having a 25-isopropyl group).
  • 25-Cyclohexyl-avermectin Bl (doramectin, disclosed in EP 214731) has the following structure,
  • the oil formulation for injection (sold as DECTOMAXTM) for the treatment and prevention of internal and external parasite infestations in cattle.
  • the oil formulation is described in European Patent N° 393890.
  • the milbemycins are similar in structure to the avermectins, except that they are unsubstituted at the 13 -position.
  • European Patent Application 240274 discloses the use of avermectins as growth promoting agents.
  • European Patent Application 311195 discloses the use of avermectins in the prevention of fescue toxicosis in grazing animals. In both documents, a subcutaneous implant is claimed, but no teaching is provided about how such an implant would be produced.
  • European Patent Application 473223 discloses a complex bioerodible implant in which active agents such as anthelmintics are incorporated covalently into a chain backbone of a constituent polymer.
  • European Patent Application 537998 discloses a drug delivery device compounded of a polymeric matrix, a vehicle (which is a plasticizing solvent for the polymeric matrix) and a drug.
  • the drug may be an avermectin or a milbemycin, and the device is intended for topical delivery of drugs, such as a flea or tick collar for pets.
  • a solid implant comprising at least one parasiticidal compound having low aqueous solubility; and tabletting excipients including a bulking agent.
  • Implants according to the invention may be implanted intramuscularly. Preferably however, they are implanted subcutaneously (i.e. into the fatty tissue directly below the skin).
  • Suitable parasiticidal compounds are those having an aqueous solubility below 100 ⁇ g/ml, for example the avermectins and milbemycins.
  • Doramectin is of particular interest (which has an aqueous solubility of 0.6 ⁇ g/ml at pH 7). Ivermectin is also of interest.
  • the bulking agent is lactose.
  • suitable bulking agents include other sugars, microcrystalline cellulose (which is available commercially as AVICELTM) and dicalcium phosphate.
  • tabletting excipients which may be present include magnesium stearate, which acts as a lubricant to facilitate tabletting. Typically, magnesium stearate will make up about 3% of the implant, by weight. Binding agents may also be included in the formulation to aid granulation and compressibility. Examples of binding agents include starch, gelatin and polyvinyl pyrrolidone. Typically, the binding agent, when present, will make up between 2 to 10% of the implant, by weight.
  • a further tabletting excipient which the implants of the invention may optionally contain is a tablet disintegrant.
  • Suitable tablet disintegrants include sodium starch glycolate, which is available commercially as EXPLOTABTM.
  • Other disintegrants which may be mentioned are dicalcium phosphate and cross-linked starch.
  • the disintegrant when present, will make up about 5% of the implant, by weight.
  • the parasiticidal compound makes up between 10 and 60% of the implant, by weight, more preferably from 20 to 45% of the implant, by weight, for example 40%.
  • the implants of the invention contain an antioxidant or a reducing agent. It has been found that such additives reduce or eliminate degradation of the parasiticidal compound, thus extending the shelf-life of the implant. It has been found that such additives are particularly useful for stabilizing the parasiticidal compound when the implant is sterilized by irradiation, such as gamma or beta irradiation.
  • Antioxidants of particular interest are butylated hydroxy anisole (BHA; a mixture of 2-tert- butyl-4-methoxyphenol and 3-tert-butyl-4-methoxyphenol) and butylated hydroxy toluene (BHT; 2,6-di-tert-butyl-4-methylphenol).
  • BHA butylated hydroxy anisole
  • BHT butylated hydroxy toluene
  • Other antioxidants and reducing agents include alpha-tocopherol, alkyl gallate derivatives, nordihydroguaiaretic acid, ascorbic acid, sodium metabisulphate and sodium sulphite.
  • the antioxidant when present, will make up between 0.01 to 0.5% of the implant, by weight, more preferably 0J to 0.2%.
  • the implants of the invention may be irradiated to sterilize them, typically at a dose in the range 15-25 kGy (kilo Gray).
  • the implants of the invention may be implanted in various parts of the animal to be treated, for example the flank, the base of the tail or the ear. Where the ears are removed during a meat rendering process, this is a preferred site for implantation.
  • the implants are preferably rod-shaped, and can be implanted conveniently using a conventional hand-operated implant gun.
  • rod- shaped implants are 2 to 30 mm in length, and 2 to 5 mm in diameter. Preferred dimensions are 5 to 6 mm in length, and 2 to 3 mm in diameter.
  • the cross section is circular.
  • a method for the treatment or prevention of parasitic infections which comprises administering an implant as defined above to an animal in need of such treatment.
  • Parasitic infections of particular interest are those caused by endoparasites including helminthiasis (most frequently caused by nematode worms in the gastrointestinal tract).
  • the implants are also useful in treatment or prevention of ectoparasite infections such as of ticks, mites, lice, fleas, blowfly, biting insects and migrating dipterous larvae.
  • the dosage to be administered will depend on the animal to be treated, the parasiticidal compound being used, and the condition to be treated. However, a suitable dose of doramectin is 0.5 mg ⁇ g of animal body weight.
  • an implant according to the invention having the preferred dimensions mentioned above will contain about 10 mg of doramectin.
  • 6 implants will be needed. This could provide sustained release of doramectin for up to 120 days. Where multiple implants are required, these can often be implanted consecutively by a single actuation of an implant gun.
  • implants according to the present invention can provide sustained release in cattle over an entire grazing season, administration need only take place once a year. Therefore, the invention provides the use of an avermectin or a milbemycin compound in the manufacture of an implant for treatment or prevention of parasitic infections, characterized in that the medicament is administered once a year.
  • the implants of the invention may be prepared by dry- or wet-mass granulation followed by milling and compression into the desired shape using conventional techniques.
  • an implant consisting of doramectin, lactose and magnesium stearate could be prepared by dry-mass granulation using the following steps:
  • Blend 4 Add half of magnesium stearate
  • the steps for wet-mass granulation are similar, except that some components are sprayed onto other components while they are blending, in a solvent which is later removed.
  • a binder is used to aid the adherence of the individual particles.
  • BHA and PNP can be added to a blending mixture of components by spraying as a solution in ethanol.
  • an implant consisting of doramectin, lactose, sodium starch glycolate, BHA, PVP and magnesium stearate could be prepared by wet-mass granulation using the following steps:
  • Blend 10 Add magnesium stearate
  • a process for the production of an implant as defined above which comprises mixing the parasiticidal compound with the tabletting excipients and forming into the desired shape.
  • the duration of action of the implants of the invention may be determined by measuring blood plasma levels in cattle following implantation. These levels have been correlated with antiparasitic activity of the compounds which have established that for effective control of helminths a blood plasma level of about 2 ng/ml needs to be maintained, and that for effective control of single-host ticks a blood plasma level of about 5 ng/ml needs to be maintained.
  • the invention further provides use of an antioxidant or a reducing agent in a composition containing an avermectin or a milbemycin for preventing degradation of the avermectin or milbemycin.
  • an antioxidant or a reducing agent in a composition containing an avermectin or a milbemycin for preventing degradation of the avermectin or milbemycin.
  • BHA has been used previously in association with doramectin in DECTOMAXTM, its function was to prevent rancidity of the oil formulation rather than to aid the stability of doramectin in solution.
  • This aspect of the invention is particularly useful when the formulation is irradiated, and may be used in liquid and non-liquid formulations (such as solids and powders).
  • FIG 1 shows the blood plasma levels in cattle achieved by the implants prepared in Examples 1 and 2;
  • Figure 2 shows the degradation profiles of implants prepared in Example 4.
  • the collected granules were then blended for 15 minutes, and then the remaining half of the magnesium stearate was added and blending continued for 5 minutes.
  • the blend was then compressed on a suitable tablet machine using 2 mm tooling to produce rod-shaped implants of 2 mm diameter and 5 mm length.
  • the implants were prepared by the method of Example 1.
  • Example 4 The implants of Examples 1 and 2 were implanted into 16 cows at a dose of 500 ⁇ g/kg.
  • the blood plasma concentrations of doramectin following implantation were measured, and the results are shown in Figure 1. It can be seen that in each case single-host tick activity was obtained for more than 50 days, and control of helminths was obtained for about 90 days.
  • Example 4
  • the collected granules were then blended for 15 minutes, and the magnesium stearate was added and blending continued for a further 5 minutes.
  • the blend was then compressed on a suitable tabletting machine using a 2mm tooling to produce rod-shaped implants of 2mm diameter and 5 mm length.
  • Implants containing 0.5% w/w BHA and having been treated at four different irradiation levels [control (0 kGy), 15 kGy, 20 kGy and 25 kGy] were stored at 30°C for 30 weeks, and then the percentage of doramectin remaining was determined.
  • a control implant containing no BHA was also studied.

Abstract

The invention provides a solid implant comprising at least one parasiticidal compound having low aqueous solubility; and tabletting excipients including a bulking agent. Implants according to the invention are convenient to administer and provide prolonged protection against parasites.

Description

Parasiticidal formulations
This invention relates to a solid implant containing a parasiticidal compound having low aqueous solubility, which is particularly useful for administration to livestock such as cattle, pigs and sheep.
A number of potent macrocyclic parasiticidal compounds are known, including the avermectins and milbemycins. UK Patent N° 1,573,955 discloses a family of avermectin compounds (including avermectins Bla and Bib) which are indicated as parasiticides.
22,23-Dihydroavermectin Bl (ivermectin, disclosed in EP 1689) is available commercially in an injectable formulation (sold as IVOMEC™). Ivermectin is a mixture of at least 80% 22,23 -dihydroavermectin Bla (having a 25-sec butyl group) and not more than 20% of 22,23 -dihydroavermectin Bib (having a 25-isopropyl group).
25-Cyclohexyl-avermectin Bl (doramectin, disclosed in EP 214731) has the following structure,
and is available commercially in an oil formulation for injection (sold as DECTOMAX™) for the treatment and prevention of internal and external parasite infestations in cattle. The oil formulation is described in European Patent N° 393890. The milbemycins are similar in structure to the avermectins, except that they are unsubstituted at the 13 -position.
Although formulations such as DECTOMAX™ have been successful, there is a need for further formulations which are convenient to administer and which provide prolonged protection against parasites.
European Patent Application 240274 discloses the use of avermectins as growth promoting agents. European Patent Application 311195 discloses the use of avermectins in the prevention of fescue toxicosis in grazing animals. In both documents, a subcutaneous implant is claimed, but no teaching is provided about how such an implant would be produced.
European Patent Application 473223 discloses a complex bioerodible implant in which active agents such as anthelmintics are incorporated covalently into a chain backbone of a constituent polymer.
European Patent Application 537998 discloses a drug delivery device compounded of a polymeric matrix, a vehicle (which is a plasticizing solvent for the polymeric matrix) and a drug. The drug may be an avermectin or a milbemycin, and the device is intended for topical delivery of drugs, such as a flea or tick collar for pets.
Thus, according to the present invention, there is provided a solid implant comprising at least one parasiticidal compound having low aqueous solubility; and tabletting excipients including a bulking agent.
An important feature of the implants of the present invention is their simplicity. Preferably therefore, greater than 95% by weight of the implant is made up of parasiticidal compound and tabletting excipients, more preferably greater than 99% by weight. Implants according to the invention may be implanted intramuscularly. Preferably however, they are implanted subcutaneously (i.e. into the fatty tissue directly below the skin).
Suitable parasiticidal compounds are those having an aqueous solubility below 100 μg/ml, for example the avermectins and milbemycins. Doramectin is of particular interest (which has an aqueous solubility of 0.6 μg/ml at pH 7). Ivermectin is also of interest.
Preferably, the bulking agent is lactose. Other suitable bulking agents include other sugars, microcrystalline cellulose (which is available commercially as AVICEL™) and dicalcium phosphate.
Other tabletting excipients which may be present include magnesium stearate, which acts as a lubricant to facilitate tabletting. Typically, magnesium stearate will make up about 3% of the implant, by weight. Binding agents may also be included in the formulation to aid granulation and compressibility. Examples of binding agents include starch, gelatin and polyvinyl pyrrolidone. Typically, the binding agent, when present, will make up between 2 to 10% of the implant, by weight.
A further tabletting excipient which the implants of the invention may optionally contain is a tablet disintegrant. Suitable tablet disintegrants include sodium starch glycolate, which is available commercially as EXPLOTAB™. Other disintegrants which may be mentioned are dicalcium phosphate and cross-linked starch. Typically, the disintegrant, when present, will make up about 5% of the implant, by weight.
Preferably, the parasiticidal compound (or compounds) makes up between 10 and 60% of the implant, by weight, more preferably from 20 to 45% of the implant, by weight, for example 40%.
Preferably, the implants of the invention contain an antioxidant or a reducing agent. It has been found that such additives reduce or eliminate degradation of the parasiticidal compound, thus extending the shelf-life of the implant. It has been found that such additives are particularly useful for stabilizing the parasiticidal compound when the implant is sterilized by irradiation, such as gamma or beta irradiation.
Antioxidants of particular interest are butylated hydroxy anisole (BHA; a mixture of 2-tert- butyl-4-methoxyphenol and 3-tert-butyl-4-methoxyphenol) and butylated hydroxy toluene (BHT; 2,6-di-tert-butyl-4-methylphenol). Other antioxidants and reducing agents include alpha-tocopherol, alkyl gallate derivatives, nordihydroguaiaretic acid, ascorbic acid, sodium metabisulphate and sodium sulphite. Typically, the antioxidant, when present, will make up between 0.01 to 0.5% of the implant, by weight, more preferably 0J to 0.2%.
As mentioned above, the implants of the invention may be irradiated to sterilize them, typically at a dose in the range 15-25 kGy (kilo Gray).
The implants of the invention may be implanted in various parts of the animal to be treated, for example the flank, the base of the tail or the ear. Where the ears are removed during a meat rendering process, this is a preferred site for implantation.
To facilitate such implantation, the implants are preferably rod-shaped, and can be implanted conveniently using a conventional hand-operated implant gun. Suitably, rod- shaped implants are 2 to 30 mm in length, and 2 to 5 mm in diameter. Preferred dimensions are 5 to 6 mm in length, and 2 to 3 mm in diameter. Preferably, the cross section is circular.
According to the invention, there is also provided a method for the treatment or prevention of parasitic infections which comprises administering an implant as defined above to an animal in need of such treatment.
Parasitic infections of particular interest are those caused by endoparasites including helminthiasis (most frequently caused by nematode worms in the gastrointestinal tract). The implants are also useful in treatment or prevention of ectoparasite infections such as of ticks, mites, lice, fleas, blowfly, biting insects and migrating dipterous larvae. The dosage to be administered will depend on the animal to be treated, the parasiticidal compound being used, and the condition to be treated. However, a suitable dose of doramectin is 0.5 mg^g of animal body weight. Typically, an implant according to the invention having the preferred dimensions mentioned above will contain about 10 mg of doramectin. Thus, for cattle weighing 120 kg, 6 implants will be needed. This could provide sustained release of doramectin for up to 120 days. Where multiple implants are required, these can often be implanted consecutively by a single actuation of an implant gun.
Because implants according to the present invention can provide sustained release in cattle over an entire grazing season, administration need only take place once a year. Therefore, the invention provides the use of an avermectin or a milbemycin compound in the manufacture of an implant for treatment or prevention of parasitic infections, characterized in that the medicament is administered once a year.
The implants of the invention may be prepared by dry- or wet-mass granulation followed by milling and compression into the desired shape using conventional techniques.
For example, an implant consisting of doramectin, lactose and magnesium stearate could be prepared by dry-mass granulation using the following steps:
1. Blend components except magnesium stearate
2. Sieve through a screen
3. Blend 4. Add half of magnesium stearate
5. Blend
6. Compress into slugs
7. Mill slugs to granules
8. Collect desired size fraction of granules 9. Blend
10. Add remaining magnesium stearate
1 1. Blend 12. Compress into rods
The steps for wet-mass granulation are similar, except that some components are sprayed onto other components while they are blending, in a solvent which is later removed. In addition, a binder is used to aid the adherence of the individual particles. For example, in the preparation of an implant containing BHA and the binder PVP, BHA and PNP can be added to a blending mixture of components by spraying as a solution in ethanol. Thus, an implant consisting of doramectin, lactose, sodium starch glycolate, BHA, PVP and magnesium stearate could be prepared by wet-mass granulation using the following steps:
1. Blend components except magnesium stearate, BHA and PVP
2. Sieve through a screen
3. Blend
4. Spray solution of BHA and PVP in ethanol onto mixture while mixing 5. Sieve wet mass
6. Dry to granules
7. Mill
8. Collect desired size fraction
9. Blend 10. Add magnesium stearate
11. Blend
12. Compress into rods
Thus, according to a further aspect of the invention, there is provided a process for the production of an implant as defined above, which comprises mixing the parasiticidal compound with the tabletting excipients and forming into the desired shape.
The duration of action of the implants of the invention may be determined by measuring blood plasma levels in cattle following implantation. These levels have been correlated with antiparasitic activity of the compounds which have established that for effective control of helminths a blood plasma level of about 2 ng/ml needs to be maintained, and that for effective control of single-host ticks a blood plasma level of about 5 ng/ml needs to be maintained.
In a broader aspect, the invention further provides use of an antioxidant or a reducing agent in a composition containing an avermectin or a milbemycin for preventing degradation of the avermectin or milbemycin. Although BHA has been used previously in association with doramectin in DECTOMAX™, its function was to prevent rancidity of the oil formulation rather than to aid the stability of doramectin in solution. This aspect of the invention is particularly useful when the formulation is irradiated, and may be used in liquid and non-liquid formulations (such as solids and powders).
The invention is illustrated by the following examples, and the accompanying figures in which:
Figure 1 shows the blood plasma levels in cattle achieved by the implants prepared in Examples 1 and 2; and
Figure 2 shows the degradation profiles of implants prepared in Example 4.
Example 1 Doramectin implant
mean particle size 19.27 μm (volume mean diameter)
The components, except magnesium stearate, were blended together in a blender for 15 minutes. The blend was then sieved through a 680 μm mesh screen and blended for a further 15 minutes. After that, half of the magnesium stearate was added and blending continued for 5 minutes, after which the blend was compressed to form "slugs". The slugs were then milled to form granules, and the size fraction 250-355 μm was collected.
The collected granules were then blended for 15 minutes, and then the remaining half of the magnesium stearate was added and blending continued for 5 minutes. The blend was then compressed on a suitable tablet machine using 2 mm tooling to produce rod-shaped implants of 2 mm diameter and 5 mm length.
Example 2 Doramectin implant containing a tablet disintegrant
mean particle size 19.27 μm (volume mean diameter)
The implants were prepared by the method of Example 1.
Example 3 Pharmacokinetic profiling
The implants of Examples 1 and 2 were implanted into 16 cows at a dose of 500μg/kg. The blood plasma concentrations of doramectin following implantation were measured, and the results are shown in Figure 1. It can be seen that in each case single-host tick activity was obtained for more than 50 days, and control of helminths was obtained for about 90 days. Example 4
Doramectin implant containing an antioxidant
The components, except magnesium stearate, butylated hydroxy anisole and polyvinyl pyrrolidone, were blended together in a blender for 15 minutes. The blend was then sieved through a 680 μm mesh screen and blended for a further 15 minutes. After that, the butylated hydroxy anisole and polyvinyl pyrrolidone was dissolved in ethanol to form the granulation fluid. The volume of ethanol used was approximately 20%, by volume, of the total formulation. The granulation fluid was sprayed onto the blend under constant mixing over 10 minutes. The resultant wet granule mass was sieved through a 1.4 mm mesh screen and allowed to dry under vacuum for 3 hours at 50°C. The dried granules were then milled, and the size fraction 250-355 μm was collected.
The collected granules were then blended for 15 minutes, and the magnesium stearate was added and blending continued for a further 5 minutes. The blend was then compressed on a suitable tabletting machine using a 2mm tooling to produce rod-shaped implants of 2mm diameter and 5 mm length.
These implants were used in stability studies, in which the effects of BHA and electron beam irradiation were investigated. Implants containing 0.5% w/w BHA and having been treated at four different irradiation levels [control (0 kGy), 15 kGy, 20 kGy and 25 kGy] were stored at 30°C for 30 weeks, and then the percentage of doramectin remaining was determined. A control implant containing no BHA was also studied.
The results are shown in Figure 2. It can be seen that the presence of BHA dramatically improves the stability of the implants on storage, even when the implants have been irradiated.

Claims

Claims:
I . A solid implant comprising at least one parasiticidal compound having low aqueous solubility; and tabletting excipients including a bulking agent. 2. An implant as claimed in claim 1, which is adapted for subcutaneous implantation.
3. An implant as claimed in claim 1 or claim 2, wherein the parasiticidal compound has an aqueous solubility below 100 μg/ml.
4. An implant as claimed in claim 3, wherein the parasiticidal compound is an avermectin or a milbemycin. 5. An implant as claimed in claim 4, wherein the parasiticidal compound is doramectin.
6. An implant as claimed in any one of the preceding claims, wherein the bulking agent is lactose.
7. An implant as claimed in any one of the preceding claims, wherein the tabletting excipients include magnesium st&arate.
8. An implant as claimed in any one of the preceding claims, wherein the tabletting excipients include a tablet disintegrant.
9. An implant as claimed in claim 8, wherein the tablet disintegrant is sodium starch glycolate. 10. An implant as claimed in any one of the preceding claims, which contains an antioxidant or a reducing agent.
I I. An implant as claimed in claim 10, wherein the antioxidant is butylated hydroxy toluene or butylated hydroxy anisole.
12. An implant as claimed in any one of the preceding claims, which is suitable for sterilization, or has been sterilized, by irradiation.
13. An implant as claimed in any one of the preceding claims, wherein the tabletting excipients include polyvinyl pyrrolidone.
14. An implant as claimed in any one of the preceding claims, wherein the parasiticidal compound makes up between 10 and 60% of the implant, by weight. 15. An implant as claimed in any one of the preceding claims, which is adapted for implantation into the ears of cattle or sheep. 16. An implant as claimed in any one of the preceding claims, which is rod-shaped.
17. Use of an antioxidant or a reducing agent in a formulation containing an avermectin or a milbemycin for preventing degradation of the avermectin or milbemycin.
18. The use as claimed in claim 17, wherein the formulation is suitable for sterilization, or has been sterilized, by irradiation. 19. The use as claimed in claim 17 or claim 18, wherein the formulation is not liquid.
20. A process for the production of an implant as defined in claim 1, which comprises mixing the parasiticidal compound with the tabletting excipients and forming into the desired shape.
21. A method for the treatment or prevention of parasitic infections which comprises administering an implant as defined in any one of claims 1-16 to an animal in need of such treatment.
EP98951367A 1997-09-23 1998-09-04 Parasiticidal formulations Withdrawn EP1014970A1 (en)

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
GB9720228 1997-09-23
GBGB9720228.7A GB9720228D0 (en) 1997-09-23 1997-09-23 Parasiticidal formulations
GBGB9810143.9A GB9810143D0 (en) 1998-05-12 1998-05-12 Parasiticidal formulations
GB9810143 1998-05-12
PCT/EP1998/005720 WO1999015166A1 (en) 1997-09-23 1998-09-04 Parasiticidal formulations

Publications (1)

Publication Number Publication Date
EP1014970A1 true EP1014970A1 (en) 2000-07-05

Family

ID=26312302

Family Applications (1)

Application Number Title Priority Date Filing Date
EP98951367A Withdrawn EP1014970A1 (en) 1997-09-23 1998-09-04 Parasiticidal formulations

Country Status (13)

Country Link
EP (1) EP1014970A1 (en)
JP (1) JP2001517622A (en)
AP (1) AP9801350A0 (en)
AR (1) AR013509A1 (en)
AU (1) AU9742298A (en)
BR (1) BR9812385A (en)
CA (1) CA2304283A1 (en)
GT (1) GT199800149A (en)
MA (1) MA24655A1 (en)
PA (1) PA8459501A1 (en)
PE (1) PE117199A1 (en)
TN (1) TNSN98175A1 (en)
WO (1) WO1999015166A1 (en)

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AUPP279698A0 (en) * 1998-04-03 1998-04-30 Sunscape Developments Limited Sustained release formulation
US6645192B2 (en) 1998-09-30 2003-11-11 Ivy Animal Health, Inc. Pellet implant system for immediate and delayed release of antiparasitic drug
AU1556000A (en) * 1999-11-22 2001-06-04 Akzo Nobel N.V. Composition allowing predefined and controlled release of active ingredient, preparation thereof and use
US6953586B1 (en) 2000-06-08 2005-10-11 Ivy Animal Health, Inc. Growth promoting pharmaceutical implant
DE10032878A1 (en) * 2000-07-06 2002-01-17 Bayer Ag Anthelmintics to prevent parasitic infections in humans and animals
AUPR602401A0 (en) 2001-06-29 2001-07-26 Smart Drug Systems Inc Sustained release delivery system
AUPR602501A0 (en) * 2001-06-29 2001-07-26 Smart Drug Systems Inc Sustained release pharmaceutical composition
AUPR610501A0 (en) * 2001-07-04 2001-07-26 Smart Drug Systems Inc Treatment of parasitic disease
US7918863B2 (en) 2005-06-24 2011-04-05 Conceptus, Inc. Minimally invasive surgical stabilization devices and methods
EP3634583A4 (en) * 2017-06-06 2021-03-03 Merck Sharp & Dohme Corp. Long-action implant for treatment of infectious diseases

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0240274A3 (en) * 1986-04-03 1990-03-14 Merck & Co. Inc. Avermectins as growth promotant agents
US4847243A (en) * 1987-10-08 1989-07-11 Merck & Co., Inc. Treatment for fescue toxicosis in grazing animals
NZ239370A (en) * 1990-08-22 1994-04-27 Merck & Co Inc Bioerodible implantable controlled release dosage form comprising a poly(ortho ester) or a polyacetal with an active agent incorporated into the chain backbone
US5411737A (en) * 1991-10-15 1995-05-02 Merck & Co., Inc. Slow release syneresing polymeric drug delivery device

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9915166A1 *

Also Published As

Publication number Publication date
TNSN98175A1 (en) 2005-03-15
AU9742298A (en) 1999-04-12
JP2001517622A (en) 2001-10-09
AP9801350A0 (en) 2000-03-17
GT199800149A (en) 2000-03-15
BR9812385A (en) 2000-09-12
WO1999015166A1 (en) 1999-04-01
AR013509A1 (en) 2000-12-27
CA2304283A1 (en) 1999-04-01
PE117199A1 (en) 1999-11-20
MA24655A1 (en) 1999-04-01
PA8459501A1 (en) 2000-05-24

Similar Documents

Publication Publication Date Title
EP1035835B1 (en) Long acting injectable formulations containing hydrogenated castor oil
US5439924A (en) Systemic control of parasites
CA2351730C (en) Antiparasitic formulations containing avermectin 13-monosaccharide 5-oxime
US6653288B1 (en) Injectable anthelmintic compositions and methods for using same
CZ300822B6 (en) Liquid polymeric compositions for controlled release of bioactive substances
AU684515C (en) Pour-on formulations containinng polymeric material, glycols and glycerides
EP1014970A1 (en) Parasiticidal formulations
KR20120006987A (en) Macrocyclic lactone drug delivery system
KR20100020003A (en) Stable non-aqueous pour-on compositions
EP2080515A1 (en) Pharmaceutical formulations containing flavouring substances with improved pharmaceutical properties
AU660205B2 (en) Systemic control of parasites
KR20150094643A (en) Tablets with improved acceptance and good storage stability
EP2598151B1 (en) Compositions for treating heartworm infestation
CN110022862B (en) Pharmaceutical preparation and process for producing the same
MXPA00002843A (en) Parasiticidal formulations
US20050169966A1 (en) Growth promoting pharmaceutical implant
EP3609470B1 (en) Implant for treating parasites infestations
WO2022269042A1 (en) Palatable veterinary compositions
WO2005039568A1 (en) Multiple active agents such as anthelmintics sustained release delivery
HU208252B (en) Process for producing solution against parasites and comprising avermectin derivative

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20000317

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU NL PT SE

17Q First examination report despatched

Effective date: 20010713

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20050108