Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Biocides; animal or insect repellents or attractants
Patent
1996-03-13
1998-11-24
Mullis, Jeffrey C.
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Biocides; animal or insect repellents or attractants
424439, 424438, 424442, 424499, A61K 914, A61K 952
Patent
active
058403248
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
This invention concerns the delivery of anti-parasitic agents to ruminant animals. More particularly, the invention concerns delivery of such agents in a controlled manner to enable the agent to have maximum effect on the parasite for longer times than is possible with conventional formulations.
BACKGROUND ART
Anti-parasitic agents are frequently delivered to ruminants in the form of oral drenches directly into the rumen. Because of chemical and bacterial degradation, association with digesta, uncontrolled absorption and excretion, the dosages required for useful effect will generally need to be considerably in excess of what might be anticipated from observation of in vitro exposure of a parasite to a given anti-parasitic agent. The elevated dosages are undesirable not only from the direct cost point of View, but also because of the contribution to the accumulation of is chemical residues (i) in edible tissues and, (ii) in the environment as they are excreted from the animal.
The present invention avoids the aforementioned disadvantages associated with prior art anti-parasitic agent administration, in that it permits greater anti-parasitic action to be achieved with existing dosages, or allows existing rates of parasite control to be maintained with lower dosage rates. The invention is based on the discovery of a novel concept of staged delivery of anti-parasitic agent to three sites, the rumen, the abomasum and the small intestine.
An important function of the rumen is to break down materials ingested by the animal in order to facilitate their absorption and utilisation. There are some nutrients from which better economic benefits would be derived if they were to pass unchanged through the rumen to become available for absorption from the abomasum or the small intestine. For example, it has been known for many years that the amino acid methionine is substantially degraded in the rumen, and that the introduction of methionine directly into the abomasum can lead to enhanced wool
growth. Ferguson et al. (1969).sup.1 and Scott et al (1972).sup.2 describe chemical carriers or coatings designed to provide feedstuffs, including amino acids, with substantially 100% protection from rumen degradation so as to enhance ruminant productive capacity. Those disclosures were specifically directed to nutritional improvement. They did, however, allude to the possibility of the various protectants having value for transporting therapeutic and prophylactic agents. Evidence that this might be so was provided by work reported by Hennessy et al.sup.3, which indicated that oral administration of albendazole (ABZ) protected from rumen degradation by encapsulation in a simple formaldehyde-treated lipid/protein matrix resulted in an increased concentration of ABZ in abomasal fluid compared with that following oral dosage with a conventional formulation from which the ABZ was freely presented to the rumen. While such prior art is acknowledged as a precursor of the present invention, the present invention is distinguished by its use of the surprising finding that the efficacy of anti-parasitic agents can be dramatically improved by administering them in a form which specifically and proportionally divides the dose and ensures a controlled degree of availability at various sites in the gastrointestinal tract, including the rumen, abomasum and small intestine.
Conventionally (oral) administered benzimidazole anthelmintic compounds are rapidly absorbed, predominantly from the rumen, and are extensively metabolised (with concomitant reduction in metabolite potency) before excretion in urine and bile. This behaviour significantly limits the availability of active metabolites at the sites of parasite infection--namely the lumen of the abomasum and small intestine.
Absorption of macrocyclic lactones from the rumen initiates similar metabolism. In addition, some chemical degradation of the active occurs within the rumen as well as extensive (and strong association of active with rumen digesta material. This association a
REFERENCES:
patent: 4547491 (1985-10-01), Mrozik et al.
patent: 4587247 (1986-05-01), Linn et al.
patent: 5190775 (1993-03-01), Klose
patent: 5252561 (1993-10-01), Hornykiesytsch
Hennessy et al at the Joint Conference of the New Zealand and Australian Societes for Parasitology, Auckland, New Zealand, 1992.
Hennessy et al, "The Disposition of Albendazole in Sheep", J. vet Pharmacol. Therap., 12, 1989, pp. 421-429.
Ashes John Richard
Gulati Suresh Kumar
Hennessy Desmond Ronald
Scott Trevor William
Steel John Winston
Commonwealth Scientific and Industrial Organisation
Mullis Jeffrey C.
LandOfFree
Antiparasitic compositions does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Antiparasitic compositions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Antiparasitic compositions will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1699364