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
  • A61K9/48—Preparations in capsules, e.g. of gelatin, of chocolate
  • A61K9/50—Microcapsules having a gas, liquid or semi-solid filling; Solid microparticles or pellets surrounded by a distinct coating layer, e.g. coated microspheres, coated drug crystals
  • A61K9/5073—Microcapsules having a gas, liquid or semi-solid filling; Solid microparticles or pellets surrounded by a distinct coating layer, e.g. coated microspheres, coated drug crystals having two or more different coatings optionally including drug-containing subcoatings
  • A61K9/5078—Microcapsules having a gas, liquid or semi-solid filling; Solid microparticles or pellets surrounded by a distinct coating layer, e.g. coated microspheres, coated drug crystals having two or more different coatings optionally including drug-containing subcoatings with drug-free core
• • 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
  • A61K9/48—Preparations in capsules, e.g. of gelatin, of chocolate
  • A61K9/50—Microcapsules having a gas, liquid or semi-solid filling; Solid microparticles or pellets surrounded by a distinct coating layer, e.g. coated microspheres, coated drug crystals
  • A61K9/5005—Wall or coating material
  • A61K9/5015—Organic compounds, e.g. fats, sugars
• • 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
  • A61K9/48—Preparations in capsules, e.g. of gelatin, of chocolate
  • A61K9/50—Microcapsules having a gas, liquid or semi-solid filling; Solid microparticles or pellets surrounded by a distinct coating layer, e.g. coated microspheres, coated drug crystals
  • A61K9/5084—Mixtures of one or more drugs in different galenical forms, at least one of which being granules, microcapsules or (coated) microparticles according to A61K9/16 or A61K9/50, e.g. for obtaining a specific release pattern or for combining different drugs

Definitions

• This invention relates to a sustained release type of pharmaceutical vehicle and to the method of its preparation. More particularly, the invention concerns a novel and more efficient seal coating to be employed in the preparation of medicinal carriers within said pharmaceutical vehicle, said vehicle including the carrier in suitable dosage amount and form, as well as forms of tablets, capsules or pellets.
• Multicoated sustained release or delayed action type pharmaceutical tablets are known, and one type of such tablet and the method of its manufacture has been described, for example, in US. Patent 2,853,420.
• the tablet described in that patent is built up by applying to a central core or basic pellet of compressed sugar or corn starch a multiplicity of medicating impregnation layers in a series of successive coating steps.
• the core or pellet as medicated is then successively coated with from 25 to 250 coatings of a sustained or delayed action material, the thickness of the coatings being gauged so as to provide a sustaining factor of approximately one hour for each 25 coatings. This will increase the weight of the tablets another 1.5%.
• the aforenentioned patent employs a coating composition comprising a solution in 85% alcohol or in chloroform of an ether or ester of cellulose, such as for example, of methylcellulose, ethylcellulose, or cellulose acetate-phthalate. About 10% of beeswax and castor oil is added to promote plasticity and elasticity of the resulting coating.
• the coating operation is performed in a rotating pan, a layer of fine talc being applied to each batch while the coating is still soft.
• the coating is substantially neutral.
• a suflicient number of coatings is thus provided to insure predetermined delaying or sustaining action even if individual coatings are imperfect or not homogeneous.
• the coatings gradually decrease in thickness as they progress from the core in proportion to its distance from the center, and being generally not more than about 1% of this distance.
• an enteric coating composition soluble in the intestinal tract and not in the gastric fluids, an inner coating of cellulose acetate-phthalate and an outer coating of beeswax, as a combined coating on a tablet.
• the wax may serve as the inner coating and the cellulose acetate-phthalate as the outer coating.
• the combination acts to prevent attack on the medicament in the stomach.
• the coating is penetrated, there occurs a total release of the medicament.
• sustained release powders by applying to a powdered medicament a first coating of a fatty material such as a fatty alcohol, a glyceride, or beeswax in an amount ranging from 25% to by weight of the powder, the fatty material being in solution in an organic solvent such as alcohol or chloroform.
• a secondary coating of the same material or materials may also be applied.
• pellet or granule a mixture of cane sugar and corn starch, or wheat or potato or rice starch.
• the mixture is finely ground and worked into approximately round granules in a rotating pan in conventional manner to produce granules or basic pellets having a mesh size between about 10 and 20 mesh.
• Small pellets of the active medicament may also be formulated as a core.
• a given amount of medicament may be coated by spraying with a saturated solution of sucrose, or with a solution of cellulose acetate-phthalate, or with a solution of a pharmaceutical glaze or of a vegetable gum, and then tumbled in a rotating pan while drying with a blast of cool air, followed by screening to 10 to 20 mesh size.
• the core pellets are placed in a rotating pan and are subjected to treatment with a solution of an adhesive material in a volatile organic solvent in an amount sufficient to cover the surface of each pellet.
• a solution of an adhesive material in a volatile organic solvent in an amount sufficient to cover the surface of each pellet.
• the volatile solvent may be any solvent which evaporates rapidly leaving no toxic residue, for example, alcohol, ether, acetone, or chloroform.
• the total weight of medicament employed may approxi- 5 mate the total weight of pellets to be coated. Thus, where a single medicament is applied, it will be used in an amount about equal to the weight of pellets. If several drugs are applied, the total weight of the drugs will approximate the total weight of the pellets.
• the coating operation can be carried out in any conventional type of equipment, such as, for example, a 36 inch diameter coating pan of the rotating type, operating, for example, at a speed of about 30 r.p.m.
• the pan is provided with means for admitting a flow of heating or cooling air to its interior. Where the core pellet is a medicament, some of the foregoing steps can be eliminated.
• a pellet, prepared as described, and with no additional coating, will, upon oral administration, provide immediate release of the medicament into the stomach of the patient.
• an enteric coating such as a solution of cellulose acetate-phth-alate in chloroform may be applied to provide a glaze protective coating on the pellet which is unafiected by stomach juices, but which will dissolve in the alkaline intestinal fluids, releasing the medicament in the intestinal tract. If the cellulose acetate-phthal-ate solution is applied to the medicament-impregnated pellets in an amount of approximately 2 pints per 50 lbs. of pellets, a coating is produced which will withstand the action of the stomach juices for ap proximately one hour, thus providing sufficient time for average passage of the carrier into the intestinal tract.
• the problem becomes one of providing a pellet with a coating or several coatings of a retardant material in an amount suflicient to delay exposure of the medicament to the intestinal fluids for periods of 2 to hours, or more.
• the successively released drugs may be such that the second may either offset or supplement the first released drug, for example a vasodilator and a vasoconstrictor, or a soporiiic and a stimulant.
• a novel coating composition which is substantially unaifected by the stomach juices, and whichvretards the action of the intestinal fluids.
• the novel coating composition is thus enteric in character, but by reason of a slight degree of acidity it serves to neutralize the alkaline intestinal fluid and hence to delay its action on the coat ing.
• the ingredients of the coating impart to the coating a melting point higher than body temperature (98 PR), thereby further providing a retarding o1 delaying action to the effect of the intestinal fluid.
• the application of the novel coating composition to the core pellet may be regulated so to produce a total increase in weight of the pellet which will result in retardant effect with respect to the intestinal fluid action of approximately one hour.
• the actual weight increase imparted to the pellet is governed by the known rate of absorption of the medicament to be released in the intestinal tract.
• the Weight increase of a given oa g h d be of the order of magnitude of about 75 5%.
• the weight increase may be of the order of about 10%.
• an average weight increase of from about 7% to about 8%, or approximately 7.5% is generally desirable.
• each such increase in weight of the pellet of 7.5% provides an additional hour of retardation in the intestinal tract, so that by applying a succession of coatings each representing 7.5 by weight, delays of 2 to 10 or more hours may readily be attained.
• a single drug is applied to the core pellet, the entire amount may be released after a predetermined time of say 4 hours. If the drug layers are divided into two or more portions, a part may be released in 1 hour and the remainder, for example, at any other desired intervals. The same is true if two or more different drugs are employed in a single carrier.
• the novel coating composition of this invention which is only slowly affected by the intestinal fluids, comprises a mixture of not less than about by weight of a glyceride and minor amounts of at least one fatty alcohol and of beeswax.
• the glyceride will generally range between about 95 and 99% by weight of the mixture, the fatty alcohol weight between about 0.1% and 0.3%, and the beeswax weight about 0.01% and 0.05%.
• the respective ingredients are dissolved in a suitable organic volatile solvent and maintained at a temperature suflicient to keep the ingredients in solution.
• the glyceride may be any suitable glyceryl ester of a fatty acid or a hydrogenated aliphatic acid, such as, for example, glyceryl monostearate, glyceryl distearate or glyceryl ester of hydrogenated castor oil, but glyceryl monostearate is preferred.
• the fatty alcohol is any suitable long-chain alcohol, such as cetyl, myristyl, or stearyl alcohol.
• the beeswax is a purified grade, such as white bleached beeswax.
• a preferred coating composition in accordance with the invention would comprise:
• EXAMPLE 1 A tablet containing 250,000 units of penicillin (for example in the form of benzylpenicillin sodium) is manufactured by treating a weighed amount of basic pellets with an adhesive solution having the composition:
• the 160 lbs. total of portions 3 to 10 inclusive will have increased in weight by approximately 64 lbs., yielding a total weight of approximately 224 lbs. Portion It will be seen from Table 1 that, starting with 200 lbs., the A and portions each weigh 20 lbs. and are set aside, leaving 160 lbs. of medicated pellets which are to be treated with the wax solution. When this treatment is 75 5322 22 acetate'phthalate i 33: 2 is now blended in and the combined portions 2-10 are 0 p 5 treated with 1 gallon of cellulose acetate-phthalate soluand impregnating said pellets with layers of the penicillin tion, yielding at this point a total weight of 224 lbs.
• portions 2-10 are further on the pellet surfaces.
• the wax solution employed has the stomach (gastric media contact) without any noticeable composition: change until entering the intestinal tract, whereupon pellets v E from portions #2 through #10 will dissolve their surface Gbceryl monostearate 900 coatings (cellulose acetate-phthalate and acetone) and Cetyl alcohol do 25 0 th rk a lviyristyl alcohol d0 25 exp Se elf Wax 1 e Bleached White beeswax do 10
• the pellets from portion #2 Wlll expose the pen1c1ll1n chloroform 1 for absorption having no wax-like resistance against alkali (intestinal media) as have pellets #3 through #10.
• the waxy ingredients are dissolved in the chloroform and During further stages of the digestive process, pellets maintained at a temperature between 65 and 67 C. from #3 portion will release penicillin for absorption with- When the medicament has a slow rate of absorption, a in the next hour, and each succeeding hour of digestive wax solution may be employed which has the composiprocess Will further break down the wax-like coating tion: substances and allow the penicillin to be released in ac- Glycerol ester of hydrogenated castor oil grams 900 40 Egg???
• 0m medicaments may be incorporated into the pellet struc- Portions of weighed amounts totaling /6, A, ture. Medicaments usually antagonistic to one another /5, V2 (one-half) and balance are removed upon comcan be commonly used and incorporated into an overall pletion of each 7.5% increase in weight over the prevehlcle, be it tablet, capsule 0r p p r viously removed portion.
• the medicated pellets are I T bl 1; treated with the wax-like coating solutions to sustain Table 1 SCHEDULE FOR TREATMENT OF PELLETS
• Addition of Pellets removed Weight in Coatings I from Pan Weight Portion lbs., Start Weight 1.11 pounds No. of each after remainstep Percent Weight Coating Propor- Weightin ingiu Weight in tion lbs. pan Increase Pounds 1/10 20.0 180.0 1/9 20.0 160.0 7. 5 1/8 1 21.50 150. 50 7.5 1/7 23.1125 138.6750 7.5 1/6 24.8459 124.2297 7.5 1/5 26.7094 106.
• Portions 2-10 to be treated further after blending Weight of portions 2-10 will be activity after ingestion, for a predetermined time. Each hourly determination is accomplished by every 7.5% increase in weight of wax-like coatings added to the pellets.
• OAR-acetone solution When intestinal time factor is achieved, several coatings of OAR-acetone solution are applied over the waxcovered pellets and the second medicament is applied to the pellet surface (phenobarbital or other type sedative). The pellets are dried prior to being placed into vehicle of choice.
• the latter medicament Upon ingestion, be it tablet, capsule or pellet, per se, the latter medicament would be released immediately (phenobarbital or other type sedative) and upon the pellets exposing the C.A.P.-acetone coating in the stomach, no noticeable change would occur until the pellets reach the intestinal tract.
• the C.A.P.-acetone coating dissolves when in contact with intestinal fluids (alkali) and exposes its wax-like coating, which will dissolve in accordance with the hourly factor given same by the 7.5% series of Wax-like coating increases.
• the existing pellets When proper time interval is reached the existing pellets will release the former medicament (dextro-amphetamine sulfate) and the resultant therapeutic activity will take place, this activity being antagonistic to the activity caused by the first medicament released.
• This process may be reversed and time interval of antagonistic activity can be controlled in accordance with the amounts of series of wax-like coatings utilized in the pellet treatment.
• EXAMPLE 3 Medicaments such as salicylates, ferrous compounds, Zoxazolamine and phenylbutazine, which tend to cause discomfort when in contact with the stomach and when oft times have to be taken every four hours for therapeutic results, fall within the scope of this invention.
• the medicament is coated upon the core pellet, or the core pellet can be made of the medicament itself, and then treated with a series of a four-hour duration, with the wax-like textured coating. Another dosage of medicament may be applied at this stage over the medicated wax-treated pellets, and another series of wax-like coatings may be applied say for another four-hour duration.
• This pellet will release active medicament at every fourhour interval. Still another series of wax-like coatings is further added to the pellet surface to sustain activity for an additional four hours in the intestines. The last dosage of medicant is applied over this wax-like coating, and the pellet is sealed with C.A.P.-acetone solution. The pellets are then dried and placed into proper vehicles (tablets, capsules or the pellets, per se).
• the vehicle Upon ingestion the vehicle will release its pellets.
• the pellets Will pass through the stomach without any noticeable change and then enter the intestinal tract.
• the C.A.P.-acetone covering is dissolved and a dosage of medicaments is released for absorption, exposing the outer series of wax-like coatings which will slowly dissolve and expose the second layer or dosage of medicaments for absorption at the fourhour sustaining period.
• This example illustrates the scope of the invention by allowing three distinct dosages of medication to be incorporated into each individual pellet. 'Ihe medications being of a type incompatible with gastric activity, by utilizing this invention we eliminate discomfort to the patient and allow the individual to ingest one tablet, capsule or fixed amount of pellets, per se, instead of three individual dosage forms.
• EXAMPLE 4 Utilizing the method as set forth in Example 1, larger doses of medications may be incorporated into tablets, capsules or pellets, per se.
• tablets containing the exact amount of medication are taken by the patient in accordance with the physicians instructions and with the recommended dosage as stated.
• Pellets containing overall larger dosages are fabricated in accordance with the concept as set forth in this invention. These pellets are coated with enough medicament to construct a tablet or capsule or fixed amount of pellets, per se, to total 40 mgm. of active medicament (Isopropyl Arterenol Hydrochloride).
• the unprotected medically coated pellets which comprise of the overall batch of treated pellets, will release their portion of medicant for absorption (4 mgm.) within the first hour.
• the remaining 7 of the pellets (36 mgm.) pass through the stomach unchanged due to its protective gastric coating (C.A.P.- acetone coating) and upon entering the intestinal tract, said coating will dissolve.
• Intestinal activity continues and each hour of said activity will enable another portion of pellets to release its medicant.
• the scope of this invention enables larger doses of medicant to be incorporated into one dosage, from pellets made into a tablet, capsule or the pellets, per se, in weighed, calculated amounts, and yet releases in any one hour not more than the recommended dosage, as determined by common practice.
• a sustained release type pharamaceutical pellet comprising an inner core coated With a member of the group consisting of sucrose, cellulose acetate-phthalate, pharmaceutical glazes and vegetable gums and having at least one surrounding layer of a medicament thereon, a coating upon each medicament layer comprising a mixture of not less than about by weight of said coating of a glyceride of a long chain aliphatic carboxylic acid, and minor amounts of at least one long chain fatty alcohol and of beeswax, the weight of each coating being between about 5% and about 10% by weight of that portion of said The ninth hour will enable thepellet coated thereby, each such coating providing approximately an hourly increment of sustainment.
• a sustained release type pharmaceutical tablet comprising a mixture of pellets as claimed in claim 1, said tablet having a sustainment time of at least one hour.
• a sustained release type pharmaceutical pellet comprising an inner core coated with a member of the group consisting of sucrose, cellulose acetate-phthalate, pharmaceutical glazes and vegetable gums and having at least one surrounding layer of a medicament thereon, a coating upon each medicament layer comprising a mixture of not less than about 95% by weight of said coating of a glyceride of a long chain aliphatic carboxylic acid, and minor amounts of at least one long chain fatty alcohol and of beeswax, the weight of each coating being about 7.5% by weight of that portion of said pellet coated 10 thereby, each such coating providing approximately an hourly increment of sustainment.

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• Health & Medical Sciences (AREA)
• Engineering & Computer Science (AREA)
• Bioinformatics & Cheminformatics (AREA)
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• Medicinal Chemistry (AREA)
• Pharmacology & Pharmacy (AREA)
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• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
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Cited By (33)

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Citations (6)

• 0
  • NL NL122039D patent/NL122039C/xx active
  • NL NL270408D patent/NL270408A/xx unknown
• 1960
  • 1960-10-20 US US63736A patent/US3080294A/en not_active Expired - Lifetime
• 1961
  • 1961-09-29 GB GB35123/61A patent/GB935602A/en not_active Expired
  • 1961-10-17 DE DE19611467961 patent/DE1467961A1/de active Pending
  • 1961-10-18 CH CH1205561A patent/CH423100A/fr unknown
• 1965
  • 1965-02-05 BE BE659324A patent/BE659324A/xx unknown

Patent Citations (6)

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