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
  • A61P5/00—Drugs for disorders of the endocrine system
• • 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
  • A61K9/2022—Organic macromolecular compounds
  • A61K9/2031—Organic macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polyethylene glycol, polyethylene oxide, poloxamers
  • A61K9/204—Polyesters, e.g. poly(lactide-co-glycolide)
• • 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
  • A61K9/2022—Organic macromolecular compounds
  • A61K9/205—Polysaccharides, e.g. alginate, gums; Cyclodextrin
  • A61K9/2054—Cellulose; Cellulose derivatives, e.g. hydroxypropyl methylcellulose

Definitions

• the invention relates generally to veterinary pharmaceutical " compositions and formulations that control the release of the active compound therein to the animal. More specifically, the present invention discloses actives in a dual formulation that stimulates growth and weight gain in domestic animals.
• Anabolic agents are widely used to promote the growth of cattle and other domestic animals and stimulated growth promotion is desirable among the cattle farmers because it maximizes both rate of weight gain and the absolute amount of weight gain per average amount of food consumed, which is termed feed efficiency.
• steroids are supplied to the animal in the form of a bio-degradable or non-biodegradable, implantable, time release pellet(s) which is injected under the skin using an implant device. These have been proven to be successful; however, the animals may have to be implanted 2-4 times during their growth period. 5743
• the implant devices used for the subcutaneous delivery of these steroid pellets consist of a housing in the shape of a pistol with a handle, a hollow needle for injecting the pellet into the body of the animal located at the front side of the housing, and a push-rod.
• the push-rod an be slid into this hollow needle and is supported in the housing so as to be displaceable longitudinally.
• a chamber is provided in the housing and is attached to the needle.
• a magazine containing the pellets is inserted and displaceable therein.
• a longitudinally displaceable press- back device (spring ejector) is arranged in the housing parallel to the push-rod and hollow needle in the housing.
• the push-rod and press- back device are moved by a driving mechanism which is similarly provided in the housing and which can be set in motion by the operating lever (trigger) fastened to the handle.
• a driving mechanism which is similarly provided in the housing and which can be set in motion by the operating lever (trigger) fastened to the handle.
• Zeranol ( " Formula I. CAS Registry Number: 26538-44-3) is an anabolic agent which has shown impressive results in the promotion
• Formula I of weight gain and growth in cattle Zeranol, a resorcylic acid lactone derivative, has shown to be a positive influence on dynamic protein metabolism.
• current formulations containing zeranol or other such anabolic agent must be administered at least twice over the 170 day growth and development period for optimal results. Obviously, this necessitates bringing cattle in from the fields, reinjecting the implant and transporting them out again which is a laborious and time-consuming process. It has been determined that zeranol and other anabolic agents provide the best growth and weight gain results when administered early on and throughout the animal's growth cycle. This would require a dual immediate-release/sustained-release formulation which has been hereinbefore not possible.
• United States Patent No. 5,643,595 to Lewis discloses and claims a delivery system for veterinary growth promotants consisting of a biodegradable polymeric matrix that contains a steroid growth promotant and an antibiotic.
• the steroid growth promotant may consist of zeranol which is formulated within sustained-release microparticles consisting of homopolymers or copolymers of lactic and /or glycolic acid.
• Other biodegradable polymers used in the sustained-release formulations include polycaprolactone, polydioxonene, polyorthoesters, polyanhydrides, waxes, casein and mixtures thereof.
• United States Patent No. 5,427,796 also to Lewis discloses a method for increasing animal growth comprising the administration of an anabolic steroid such as zeranol in a biodegradable microparticle delivery system that releases the drug in a multiphasic manner. Drug delivery duration allegedly lasts up to 200 days.
• the same polymers are used in Lewis's other patents noted above and below.
• United States Patent Nos. 5,419,910 and 5,288,496 to Lewis also disclose and claim a microparticulate sustained-release delivery system for promoting growth in animals.
• the microparticles are comprised of a biodegradable polymeric matrix such as poly-d,l-lactic acid, polyglycolic acid and the like.
• microparticles separately encapsulate a steroid growth promotant and an antibiotic.
• Zeranol among other anabolic steroids, is disclosed as one of the useful actives that result in increased bulk weight and growth.
• United States Patent No. 4,874,612 to Deasy discloses a multi- component implant for the sustained-release, long-term delivery of pharmaceutical agents to humans and animals for the treatment of vitamin deficiencies, hormone replacement therapy, cancer therapy, infection and the like.
• the biodegradable polymers comprising the implants are used to deliver animal growth promotants which contain anabolic steroids such as zeranol as well as their combinations.
• the matrix used to make the implants consists of lactic acid/glycolic acid copolymers.
• the above-noted objects and others are addressed by aspects of the present invention which provides a method and an anabolic implant -formulation for stimulating increased rate of growth, greater amount of growth and greater feed efficiency in cattle.
• the inventive method comprises administering to the animal an implant composition (or implant as is commonly called) which comprises: (i) an immediate- release formulation containing an anabolic agent, and (ii) a controlled- release formulation containing an anabolic agent with a controlled- release agent, wherein the immediate-release formulation and the controlled-release formulation cooperate to effect the desired stimulation of growth and weight gain.
• the immediate-release formulation and the controlled-release formulation may be simultaneously administered, or one immediately followed by the other in quick succession in whichever order the administrator chooses, to the animal.
• Applicants have found that the inventive method of administering a dual formulation surprisingly results in growth and weight gain in the animal much higher than when either formulation (i) or (ii) is implanted without the other.
• the present invention further discloses a method of preparing the above-noted dual formulation, an anabolic implant composition comprising a dual formulation, as well as a method for stimulating growth and weight gain in animals using such compositions.
• this invention discloses a method for stimulating increased rate of growth, greater amount of growth and greater feed efficiency in animals, sometimes generally referred t as cattle in this application.
• the method comprises administering an anabolic implant composition which is a dual formulation comprising (i) an immediate-release formulation containing an anabolic agent, and (ii) a controlled-release formulation containing an anabolic agent and a controlled-release agent.
• the immediate-release formulation and the controlled-release formulation cooperate in the cattle to effect the desired stimulation of growth and weight gain.
• the dual formulation may be administered as one composition by simultaneous administration of both (i) and (ii) above in one administrating (injecting) device, or administered one formulation followed by the other in quick succession in whichever order the administrator prefers, the following description, for simplicity sake, describes the invention as a single step simultaneous administration method.
• the present invention concerns a method of stimulating increased rate of growth, greater amount of growth and greater feed efficiency in food animals which comprises providing to such animals biodegradable and non-biodegradable compressed tablets loaded with an anabolic agent.
• the method of the present invention provides advantages over methods known in the art such as, inter alia, increased weight gain, a biodegradable or nonbiodegradable system, an implant system, the ability to mix tablets (pellets) containing different drugs and the ability to program the release rate (multiphasic release patterns).
• administration of the growth promotant to food animals by the method of the invention is achieved by a single administration of the growth promotant loaded into compressed shapes such as, for example, tablets which release the active anabolic agent into the animal in a constant or pulsed manner and eliminates the need for repetitive injections.
• compressed shapes such as, for example, tablets which release the active anabolic agent into the animal in a constant or pulsed manner and eliminates the need for repetitive injections.
• Some of the tablets contain the active anabolic agent with no controlled-release agent, while the other tablets contain the active anabolic agent with a controlled-release agent, as described later in the Examples.
• the former acts as the immediate-release formulation while the latter acts as the controlled formulation.
• anabolic agent used in the two formulations may be the same or different.
• Illustrative anabolic agents suitable for and useful as growth promotants in the present invention include zeranol, estradiol and its derivatives such as, for example, estradiol benzoate, trenbolone acetate (Formula II, CAS Registry Number: 10161-34-9, available from Pharmacia & Upjohn Company, Kalamazoo, Michigan), somatotrophin -and its derivatives, testosterone and its derivatives such as, for example, testosterone propionate, salbutamol, progesterone, its derivatives and combinations thereof.
• the anabolic agent may be used as it is or optionally formulated with minor amounts of other materials such as, for example, diluents, excipients, tabletting agents and the like that are suitable for insertion under the skin.
• diluents such as lactose as a diluent, magnesium stearate as a lubricant, silica as a glidant and the like.
• Ralgro ® is formulated with lactose.
• Other diluent materials include, for example, mannitol, sorbitol, sucrose, dextrose, starches, hydrolyzed starches, and the like.
• the controlled-release agent is a polymer matrix.
• the polymeric matrix material must be biocompatible.
• biocompatible is defined as a polymeric material which is not toxic to an animal and is not carcinogenic.
• the matrix material is biodegradable, the polymeric material should degrade by bodily processes to products readily disposable by the body and should not accumulate therein.
• the matrix is non-biodegradable, it is still biocompatible and may remain within the animal at the site of implantation indefinitely.
• polymeric matrix materials useful in the present invention include poly(D,L-lactide-co-glycolide) copolymer, ethyl -cellulose, methyl aery late-methyl methacrylate copolymer, methylcellulose, hydroxyethyl cellulose, hydroxypropylmethylcellulose, sodium carboxymethyl cellulose, and the like.
• the anabolic agent and the polymer matrix material in the controlled-release formulation may be optionally formulated with minor amounts of other materials such as, for example, diluents, excipients, tabletting agents and the like, that are suitable for insertion under the skin.
• the implant is generally in the shape of a cylindrical tablet.
• the tablet will generally have a diameter of from about 2.0 mm to 6.0 mm and a length of from about 1.0 mm to about 4.0 mm.
• the implants for the controlled-release are generally prepared by a procedure wherein the active anabolic agent is mixed with the poly(D,L-lactide-co-glycolide) copolymer or the ethyl cellulose together with the other optional materials and this is then compressed in the die of a tabletting press as is known in the art.
• the rate of release of the anabolic agent in the controlled-release formulation can be controlled by a variety of measures.
• the rate of degradation of the carrier matrix can be increased by decreasing the size and consequently the molecular weight of the polymer chains.
• Increasing the amount of the active anabolic agent and consequently reducing the active copolymer weight ratio will increase rate of release.
• the incorporation of additional plasticizers and other excipients may even speed up the degradation and release. Such modifications will be obvious to those skilled in the art.
• the preparation of the implants containing a biodegradable polymer such as, for example, the poly(D,L-lactide-co-glycolide) copolymer may be achieved utilizing any number of methods known in the art.
• An illustrative procedure is as follows.
• the anabolic active is first dissolved in a suitable solvent that will also solubilize, emulsify or disperse the poly(D,L-lactide-co-glycolide) copolymer.
• suitable solvents include organic solvents such as acetone, chloroform, methylene chloride, other aromatic hydrocarbons, cyclic ethers, esters, alcohols and the like and mixtures thereof.
• the polymer matrix material is also dissolved or dispersed in the solvent and the emulsion or solution formed thereby may be mixed into a continuous phase.
• a surfactant may be added to the solution to prevent agglomeration.
• the solvent is then removed, generally by the application of heat, the application of reduced pressure or both.
• the temperature employed is not critical but it should not be so high as to result in a degradation of either the active compound or the implant biodegradable matrix material.
• the solid dose implants may then be prepared using a standard tabletting die press as is known in the art.
• the anabolic agent useful in the formulation of the present invention is zeranol.
• a commercially available formulation of zeranol is Ralgro ® (from Schering-Plough Corporation, Terre Haute, Indiana) which additionally contains some lactose.
• the zeranol content in the present formulation is in an amount of from about 50 wi.% to 95 wt.% preferably from about 55 wt.% to about 85 wt.% and most preferably from about 60 wt.% to about 80 wt.%, based on the total weight of the implant composition (including both the immediate- release part and the controlled-release part).
• the poly (D,L,-lactide-co-glycolide) copolymer is incorporated in the sustained-release formulation in amounts ranging from about 1.0 wt.% to about 10 wt.% and preferably from about 1.0 wt.% to about 5.0 wt.%. If ethyl cellulose is used as the agent in place of the poly(D,L- lactide-co-glycolide) copolymer, greater amounts may be used such as from about 1.0 wt.% to 8.0 wt.% and preferably from about 2.0 wt.% to about 7.0 wt.%.
• the other optional materials may be added to the formulation according to the length of drug delivery desired, but for the most part these will be added in standard amounts as is known in the art.
• a diluent or excipient may be added in amounts of from about 20 wt.% to 40 wt.%, preferably in an amount of from about 25 wt.% to 40 wt.%, and typically in amounts of from about 25 wt.% to 30 wt.%.
• Coloring dyes for foods, drugs & cosmetics ("FD & C”), and the like may be incorporated into the formulations in amounts of from 0.1 wt.% to 2.0 wt.% as is known in the art.
• Implants containing non-biodegradable polymer such as, for example, ethyl cellulose, may be prepared by procedures known in the art.
• An illustrative procedure is as follows: The anabolic agent such as zeranol is mixed with a diluent such as, for example, lactose, and optionally a suitable dye in a planetary mixer.
• a diluent such as, for example, lactose
• a suitable dye in a planetary mixer.
• an aqueous dispersion of ethylcellulose commercially available as Aquacoat
• ECD-30 ® (available from FMC Corporation, Philadelphia, Pennsylvania) is mixed with a suitable plasticizer such as triacetin, or dibutyl sebacate, etc.
• a suitable plasticizer such as triacetin, or dibutyl sebacate, etc.
• the plasticized ethyl cellulose is then blended with the anabolic agent/lactose mixture and granulated.
• the granules are dried at a temperature of from about 50° c to 70° C until the formulation is characterized by a moisture level of from about 0.2 wt.% - 0.6 wt.% based on the total weight of the formulation.
• the dried granules are then sized through a sieve, such as, for example, the Fitzmill sieve or its equivalent, and then lubricated with an appropriate lubricant such as magnesium stearate and a glidant such as, for example, silicon dioxide.
• the granules are then compressed into pellets of the desired size and hardness.
• a sieve such as, for example, the Fitzmill sieve or its equivalent
• compositions such as the commercially available zeranol product, such as, for example, Ralgro ® , may be used and compressed into suitable size tablets. Any optional ingredients such as, for example, dye and the like, may be mixed in before compressing into tablets.
• the inventive dual formulation is prepared by taking a certain number of thus-prepared tablets containing the controlled-release formulation and a certain number of thus-prepared immediate-release formulation (including Ralgro ® which is zeranol plus lactose) tablets in the injection device.
• the number of each kind is determined based on the total amount of zeranol one desires to inject into the animal.
• the dual formulation injection may be compared with injection of either the controlled formulation tablets alone or the zeranol tablets alone such that the total amount of zeranol would still match with the total zeranol in the inventive dual formulation.
• the growth enhancement implant pellets are generally subcutaneously injected into the cattle, or other domesticated animal under the ear.
• anabolic implant compositions and formulations for stimulating increased rate of growth, greater amount of growth and greater feed efficiency in cattle is a dual release formulation which comprises: (i) an immediate-release formulation containing an anabolic agent, and (ii) a controlled-release formulation containing an anabolic agent and a controlled-release agent, wherein the immediate-release formulation and the controlled-release formulation cooperate to effect the desired stimulation of growth and weight gain.
• the types and examples of (i) and (ii) are described above.
• a further embodiment of the present invention discloses a method of stimulating increased rate of growth, greater amount of growth and greater feed efficiency in cattle, whose growth, weight gain and feed efficiency need to be improved, by administering to said cattle an anabolic implant composition which is a dual release formulation which comprises: (i) an immediate-release formulation containing an anabolic agent, and (ii) a controlled-release formulation containing an anabolic agent and a controlled-release agent, wherein the immediate- release formulation and the controlled-release formulation cooperate to effect the desired stimulation of growth and weight gain.
• an anabolic implant composition which is a dual release formulation which comprises: (i) an immediate-release formulation containing an anabolic agent, and (ii) a controlled-release formulation containing an anabolic agent and a controlled-release agent, wherein the immediate- release formulation and the controlled-release formulation cooperate to effect the desired stimulation of growth and weight gain.
• a still further embodiment of the present invention concerns a method for stimulating increased rate of growth, greater amount of growth and greater feed efficiency in an animal.
• the method comprises: preparing an immediate-release formulation comprising an anabolic agent such as, for example, the agents described above, in a shaped object suitable for loading into a device such as, for example, pellets, tablets and the like, which device is suitable for administration of said shaped object into the animal (such as, for example, the pistol described earlier); preparing a controlled-release formulation containing an anabolic agent and a controlled-release agent, in a shaped object similar to above and suitable for loading into the device in step (a), wherein said anabolic agent in step (a) and said anabolic agent in step (b) may be the same or different; loading the device with the shapely object in step (a) and the -shapely object in step (b) in a ratio such that the total anabolic agent is in the 50-95 weight percent range based on the combined weight of the two formulations (i.e. the
• EXAMPLE 1 Comparison of Weight Gain with Zeranol as Immediate-release Formulation to a Formulation Containing Zeranol as Controlled-release Formulation:
• the following zeranol matrix base formulations were prepared to compare controlled-release formulations containing zeranol with Ralgro ® and a placebo (an ineffective control).
• Ralgro ® is a commercially available product of zeranol and lactose. 743
• a Controlled-release Formulation zeranol /poly (D,L- lactide-co-glycolide copolymer; 50:50 wt%) (180 mg total zeranol)
• the implants were prepared as follows.
• formulation A the poly (D,L-lactide-co-glycolide 50:50, 3.991 g) was placed in an Erlenmeyer flask and dissolved in 50 grams of ethyl acetate. Separately, the zeranol and lactose (26.606 g) were mixed together dry in a mortar to which the FD & C coloring dyes (0.44 g) were added. The solvent comprising D,L- lactide-co-glycolide and ethyl acetate was then added to the zeranol /dye /lactose mixture. The composition was then heated to 40- 45°C.
• Formulation B was prepared in a similar manner using ethyl cellulose as the polymer matrix and Aquacoat ECD-30 instead of ethyl acetate.
• Ralgro ® was made into similar size tablets using procedures known in the art.
• formulation D the control with no zeranol was made into tablets similar to in formulatioh C.
• formulation C was administered twice, once at day 0 and again at day 70, each dose containing 36 mg of zeranol.
• Each steer was weighed at selected time periods during its development and the average body weight for each group given a particular formulation A to D was calculated for each date and are as follows:

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Cited By (5)

Citations (5)

• 1999
  • 1999-11-02 AR ARP990105535A patent/AR025133A1/es active IP Right Grant
  • 1999-11-02 TW TW088119044A patent/TWI250027B/zh not_active IP Right Cessation
  • 1999-11-02 AU AU30967/00A patent/AU777393B2/en not_active Expired
  • 1999-11-02 CO CO99069032A patent/CO5140100A1/es unknown
  • 1999-11-02 BR BR9914996-6A patent/BR9914996A/pt not_active IP Right Cessation
  • 1999-11-02 WO PCT/US1999/023993 patent/WO2000025743A2/en active IP Right Grant
  • 1999-11-02 CA CA002348841A patent/CA2348841C/en not_active Expired - Lifetime
  • 1999-11-02 BR BRPI9914996 patent/BRPI9914996B8/pt unknown
  • 1999-11-03 MY MYPI99004773A patent/MY134868A/en unknown
  • 1999-11-03 PE PE1999001104A patent/PE20001092A1/es not_active IP Right Cessation
• 2001
  • 2001-04-20 CR CR6351A patent/CR6351A/es not_active Application Discontinuation
  • 2001-04-30 ZA ZA200103494A patent/ZA200103494B/xx unknown

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