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
  • A61K9/20—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
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K31/00—Medicinal preparations containing organic active ingredients
  • A61K31/33—Heterocyclic compounds
  • A61K31/395—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins
  • A61K31/495—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins having six-membered rings with two or more nitrogen atoms as the only ring heteroatoms, e.g. piperazine or tetrazines
  • A61K31/505—Pyrimidines; Hydrogenated pyrimidines, e.g. trimethoprim
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K31/00—Medicinal preparations containing organic active ingredients
  • A61K31/33—Heterocyclic compounds
  • A61K31/395—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins
  • A61K31/495—Heterocyclic compounds having nitrogen as a ring hetero atom, e.g. guanethidine or rifamycins having six-membered rings with two or more nitrogen atoms as the only ring heteroatoms, e.g. piperazine or tetrazines
  • A61K31/505—Pyrimidines; Hydrogenated pyrimidines, e.g. trimethoprim
  • A61K31/517—Pyrimidines; Hydrogenated pyrimidines, e.g. trimethoprim ortho- or peri-condensed with carbocyclic ring systems, e.g. quinazoline, perimidine
• • 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
  • A61K9/2027—Organic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polyvinyl pyrrolidone, poly(meth)acrylates
• • 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
• • 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
  • A61K9/28—Dragees; Coated pills or tablets, e.g. with film or compression coating
  • A61K9/2806—Coating materials
  • A61K9/2833—Organic macromolecular compounds
  • A61K9/284—Organic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polyvinyl pyrrolidone
  • A61K9/2846—Poly(meth)acrylates

Definitions

• This invention relates to controlled-release oral pharmaceutical formulations
• Controlled-release oral pharmaceutical formulations are known Their purpose is to modify the rate of drug release, for example to produce a constant rate of release of a drug into the gastrointestinal tract of a patient, or to delay the release of a drug into the gastrointestinal tract of a patient (see 'Sustained and Controlled Release Drug Delivery Systems', pp 3-6, edited by J R Robinson, published by Marcel Dekker Inc)
• US Patent N° 4,765,989 discloses an osmotic delivery device for delivering inter alia nifedipi ⁇ e or doxazosin It has a perforated semipermeable wall enclosing a drug composition which includes an osmopolymer, and a pusher composition containing a second osmopolymer
• a drug composition which includes an osmopolymer
• a pusher composition containing a second osmopolymer The performance of this prior art device is satisfactory, but it has the disadvantage that it is very complicated, leading to high manufacturing costs
• UK Patent Application 2,123,291 discloses a sustained release formulation of suloctidil which is a two-part tablet a first part is a prompt-release portion and a second part is a slow-release portion, which must contain a surface-active agent to promote bio-erosion
• US Patent N° 5,393,765 discloses an erodibie pharmaceutical composition providing a zero order controlled release profile, comprising low viscosity hydroxypropylmethyl cellulose
• a controlled-release pharmaceutical formulation for oral administration consisting essentially of an active drug compound low molecular weight polyethylene oxide, hydroxypropylmethyl cellulose tabletting excipients and optionally one or more enteric polymers
• formulations of the present invention may also be administered buccally (i e placed behind the top lip and allowed to dissolve) and the term includes such formulations "Consisting essentially of means that at least 95% by weight of the formulation is made up of the listed components. At least 99% by weight of uncoated formulations, and the cores of coated formulations, are preferably made up of the listed components.
• Polymerized ethylene oxide having a number average molecular weight less than 100,000 is sometimes referred to as "polyethylene glycol".
• polyethylene glycol Polyethylene glycol
• low molecular weight polyethylene oxide is used to refer to polymerized ethylene oxide in the number average molecular weight range of interest, namely 15,000 to 750,000.
• Tabletting excipients making up formulations according to the invention may be conven ⁇ tional tabletting excipients, for example dibasic calcium phosphate, lactose and magnesium stearate.
• the first class is weakly basic compounds. Examples of this class include dipyridamole, noscapine, papaverine, doxazosin, sildenafil and prazosin. Doxazosin and its pharmaceutically acceptable salts are of particular interest.
• the second class are compounds having high solubility in aqueous media.
• this class include salbutamol, metoprolol, propanolol, aminophylline, isosorbide mono- and dinitrate, glyceryl trinitrate, verapamil, captopril, diltiazem, morphine, chlorpheni- ramine, promethazine, eletriptan, darifenacin and fluconazole.
• the third class are compounds having low solubility in aqueous media.
• Examples of this class include nifedipine, griseofulvin, carbamazepine, felodipine, nimodipine and megestrol.
• solubility in aqueous media and “low solubility in aqueous media” will be understood by those skilled in the art. However, the former may be defined as a solubility
• Formulations according to the invention have the advantage that they produce a constant rate of release of drugs that are weakly basic and/or have a high solubility in aqueous media in in vitro models of the gastrointestinal tract, and so are expected to produce a constant rate of release of the drug in the gastrointestinal tract of a patient.
• the formulations of the invention have the advantage that they produce a delayed or pulsed release of the drug.
• the formulations are very simple and so can be manufactured at a compara ⁇ tively low cost.
• the hydroxypropylmethyl cellulose has a number average molecular weight in the range 80,000-250,000.
• the hydroxypropylmethyl cellulose has a degree of methyl substitution in the range 19-30 %.
• the hydroxypropylmethyl cellulose has a degree of hydroxy substitution in the range 4-12 %.
• a number of hydroxypropylme- thyl cellulose polymers are available commercially under the brand name Methocel®, and some of those suitable for use in formulations according to the invention are given in the table below:
• Methocel® K4M has characteristics of particular interest.
• the low molecular weight polyethylene oxide has a number average molecular weight in the range 20,000 to 500,000, more preferably 100,000-300,000.
• Polyethylene oxide with a number average molecular weight above 100,000 is a powder, which makes it easier to handle than lower molecular weight polyethylene oxide, which has a lower melting point.
• polyethylene oxide with a number average molecular weight of 6000 has a melting point of 60-63°C It will be apparent to those skilled in the art that the polyethylene oxide may consist of molecules of different chain lengths, but that the average chain length gives a molecular weight in the range stated. The same applies to the hydroxypropylmethyl cellulose.
• Formulations according to the invention may contain an enteric polymer admixed with the other components of the formulation.
• formulations according to the invention are preferably provided with a coating of an enteric polymer.
• Enteric polymers that may be mentioned are phthalate derivatives (including cellulose acetate phthalate, polyvinyiacetate phthalate and hydroxypropylmethyl cellulose phthalate), polyacrylic acid derivatives (including methacrylic acid copolymer), and vinyl acetate and crotonic acid copolymers. Methacrylic acid copolymer is of particular interest.
• the formulation contains up to 50% by weight of active drug compound, for example 1-20%.
• formulations of the invention contain 5-30% by weight of low molecular weight polyethylene oxide, for example 8-10%.
• the formulations of the invention contain 10-60% by weight of hydroxypropyl- methyl cellulose, for example 25-35%.
• Formulations having enteric polymer admixed with the other components of the formula ⁇ tion preferably have 10-40% by weight of admixed enteric polymer, for example 25-35%.
• the mass ratio of low molecular weight polyethylene oxide:hydroxypropylmethyl cellulose is in the range 2:1- 1 :5.
• the mass ratio of (low molecular weight polyethylene ox- ide+hydroxypropylmethyl cellulose):admixed enteric polymer is in the range 1 :2-6: 1 , more preferably 1 :2-2:1.
• the enteric coating (where present) makes up 2-15% by weight of the formulation, more preferably 5-10% by weight of the formulation.
• the use of low molecular weight polyethylene oxide in an oral controlled-release pharmaceutical formulation having a hydroxypropylmethyl cellulose matrix, to enhance the erosion of the matrix after a predetermined period of time following administration of the formulation to a patient
• the predetermined period of time is 6 hours In this way, a constant rate of drug release can be achieved in the gastrointestinal tract of a patient despite the varying conditions which exist along its length
• a process for the production of a pharmaceutical formulation as defined in claim 1 which comprises mixing an active drug compound, low molecular weight polyethylene oxide, hydroxypropylmethyl cellulose, tabletting excipients, and optionally one or more enteric polymers, followed by pressing into tablets
• formulations according to the present invention may be measured in a model of the gastrointestinal tract such as Apparatus 1 of USP 22, page
• Figure 1 shows the percentage of drug compound released v time from formulations according to the invention [as prepared in Examples 1 (a) and 1 (b)] in comparison with a control [as prepared in Example 6] using simple dissolution testing
• Figure 2 shows the percentage of drug compound released v time from a formulation according to the invention [as prepared in Example 2(a)] using dissolution testing with first an acidic and then a neutral dissolution medium
• Methacrylic acid copolymer type C a 6 500
• Example 5 Sustained release formulations of fluconazole (suitable for buccal administration.
• Example 1 The tablets of Examples 1 (a), 1 (b) and 6 were dissolved using Apparatus 1 of USP 22, page 1578, Method 1 (baskets)
• the dissolution fluid was 900ml of water at 37°C
• the rotation speed of the baskets was 100 rpm
• the drug compound released was detected by UV spectroscopy at a wavelength of 246 nm
• the percentage of drug compound released v time for each tablet type is shown in Figure 1
• Example 2(a) The tablets of Example 2(a) were dissolved using Apparatus 1 of USP 22, page 1578, Method 1 (baskets)
• the rotation speed of the baskets was 200 rpm, and the drug compound released was detected by UV spectros- copy at a wavelength of 246 nm
• the percentage of drug compound released v time is shown in Figure 2

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• Health & Medical Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Medicinal Chemistry (AREA)
• Pharmacology & Pharmacy (AREA)
• Epidemiology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Engineering & Computer Science (AREA)
• Bioinformatics & Cheminformatics (AREA)
• Medicinal Preparation (AREA)
• Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
• Acyclic And Carbocyclic Compounds In Medicinal Compositions (AREA)

Applications Claiming Priority (3)

Publications (1)

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• 1995
  • 1995-11-21 GB GBGB9523752.5A patent/GB9523752D0/en active Pending
• 1996
  • 1996-11-11 PL PL96326981A patent/PL326981A1/xx unknown
  • 1996-11-11 TR TR1998/00902T patent/TR199800902T2/xx unknown
  • 1996-11-11 HU HU9903734A patent/HUP9903734A3/hu unknown
  • 1996-11-11 SK SK630-98A patent/SK63098A3/sk unknown
  • 1996-11-11 AU AU75721/96A patent/AU709560B2/en not_active Ceased
  • 1996-11-11 NZ NZ322053A patent/NZ322053A/xx unknown
  • 1996-11-11 EP EP96938215A patent/EP0862437A1/en not_active Withdrawn
  • 1996-11-11 KR KR1019980703777A patent/KR19990071505A/ko not_active Application Discontinuation
  • 1996-11-11 JP JP9519364A patent/JPH10513481A/ja active Pending
  • 1996-11-11 WO PCT/EP1996/005020 patent/WO1997018814A1/en not_active Application Discontinuation
  • 1996-11-11 CZ CZ981554A patent/CZ155498A3/cs unknown
  • 1996-11-11 BR BR9611626A patent/BR9611626A/pt not_active Application Discontinuation
  • 1996-11-11 CN CN96198486A patent/CN1215993A/zh active Pending
  • 1996-11-11 CA CA002232715A patent/CA2232715A1/en not_active Abandoned
  • 1996-11-20 PE PE1996000831A patent/PE22898A1/es not_active Application Discontinuation
  • 1996-11-20 YU YU62096A patent/YU62096A/sh unknown
  • 1996-11-20 MA MA24397A patent/MA26410A1/fr unknown
  • 1996-11-20 AR ARP960105252A patent/AR004335A1/es unknown
  • 1996-11-20 ZA ZA9609722A patent/ZA969722B/xx unknown
  • 1996-11-20 TN TNTNSN96141A patent/TNSN96141A1/fr unknown
  • 1996-11-21 HR HR9523752.5A patent/HRP960554A2/hr not_active Application Discontinuation
  • 1996-11-21 AP APAP/P/1996/000883A patent/AP718A/en active
  • 1996-11-21 CO CO96061449A patent/CO4480020A1/es unknown
• 1998
  • 1998-03-31 IS IS4706A patent/IS4706A/is unknown
  • 1998-05-08 BG BG102438A patent/BG102438A/xx unknown
  • 1998-05-19 OA OA9800058A patent/OA10687A/en unknown
  • 1998-05-20 MX MX9804008A patent/MX9804008A/es unknown
  • 1998-05-20 NO NO982302A patent/NO982302L/no not_active Application Discontinuation

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