Pharmaceutical composition for rectal administration of active principles exhibiting a prevalently topical medication action at the colon level

Abstract: The invention provides a pharmaceutical composition for the rectal administration of active principles which exhibit a prevalently topical medication action at the colon level, characterised in that said active principles are formulated in a fluid vehicle able to generate a foam on rectal administration.

Description: This invention relates to the administration of agents which are pharmacologically active against intestinal disturbances, and provides a pharmaceutical composition which can be administered rectally for this purpose. It is of particular but not exclusive application in the administration of 5-amino-salicylic acid (hereinafter known as 5-ASA or mesalazine) for treating disturbances of the colon and rectum. The present invention is directed generally to any active principle exhibiting a prevalently topical medication action on various levels of the colon. Particularly but not exclusively it is directed towards medicaments with an antiinfectivelantibiotic, antiinflammatory/antiphlogistic, antispastic, antimeteoric, prokinetic or laxative action. It is known that in treating affections or disturbances of the colon or rectum, topical administration of the pharmacologically active agent can be used, as it rapidly reaches and acts on the point at which the disturbance is located. In the known art, such pharmacologically active agents can be administered rectally using suppositories or enemas. However, rectal administration using suppositories is generally unable to act beyond the rectal tract, whereas an enema is generally rarely able to pass beyond the left side of the colon. For the purposes of the present invention the ability of the active principles in question to retrodiffuse, ie achieve a retrograde progression as extended as possible from the point of administration along the colon and provide uniform distribution of such active principles, is very important. In this regard, it is known that for instance a 5-ASA enema (4 g in 100 ml) has appreciable retrodiffusion as far as the splenic flexure of the colon, and is therefore suitable for curing patients suffering for example from sinistral ulcerous colitis, ie a distal disease extending as far as the splenic flexure. However this enema does not normally have the capacity to retrodiffuse beyond the left side of the colon. In addition, an enema generally suffers from the serious problem of a low and often insufficient ability to persist by adhesion to the intestinal walls, and a lack of distribution uniformity, thus reducing the capacity of the active principle to act in the tract which it reaches. In this respect, according to the objects of the invention the active principle in question should not only have high retrodiffusion but should also exhibit an effective persistent and uniform action in those tracts of the colon which it succeeds in reaching. Preferably, this activity should be maintained even after intestinal evacuation by the subject treated. The active principles for medication at the colon level towards which the present invention is directed are not necessarily limited with regard to the type of therapeutic action. What they must generally possess is prevalently topical action and exhibit low systemic absorption, with high general toleration even if a certain level of systemic absorption does exist. According to the present invention as claimed in Claim 1 it has now been surprisingly found that the aforesaid objects are attained by a pharmaceutical composition for the rectal administration of an active principle which exhibits a prevalently topical anti-inflammatory action with high retrograde diffusion along the colon tract, characterised in that said active principle is budesonide formulated in a fluid vehicle able to generate a foam on rectal administration. According to the invention, the foam must be generated at the moment of therapeutical application. Hence the known formulation and dispensing technology applicable to foam cans used for example in cosmetics is therefore suitable. Here, the active principle is vehicled in the liquid state with at least one propellant and a surfactant with foaming action. At the moment of use the dispensing valve of the can allows rapid expansion of the propellant, which triggers and enhances the foaming action of the surfactant, which thus emerges to entrain the medicated liquid in the form of foam. The propellant expansion energy is absorbed mainly in forming the foam, thus allowing rectal application without risk The liquid vehicle must be water-based or more rarely based on highly hydrophilic organic substances to allow the surfactant to perform its foaming action, which however must not be inhibited by the other substances present in the formulation, such as the active principles and their stabilizers, whereas the specific adjuvants (such as foam consistency correctors) must be chosen from those with strong hydrophilic and lipophilic characteristics. In administering such compositions, it is sufficient to obtain foams of medium consistency, with a minimum volume of 100 ml of foam introduced into the rectum. In general, according to the invention a composition also comprises : suspending substances, solubilizers, preservatives etc. as active principle adjuvants; water or highly hydrophilic organic liquids (such as propyleneglycol, polyethyleneglycol) as fluid vehicle; high HLB (hydrolipophilic index) surfactants, nonionic surfactants (such as polysorbates), anionic surfactants (such as sodium laurylsulphate), or cationic surfactants (such as benzalkonium chloride) as foaming surfactants; medium HLB surfactants (such as polyoxyethyleneglycol isostearate) or typical cream emulsion thickeners (such as cetyl alcohol, propyleneglycol) as foam thickeners; freon (such as freon 12, freon 114) as propellants; hydrocarbons (such as isobutane, N-butane or propane); and miscellaneous substances (such as CO 2 N). The active principle is solubilized or suspended in a suitable liquid vehicle containing a foaming surfactant. The liquid is placed in an atomizer can sealed by a dispensing valve and then pressurized by feeding a suitable quantity of propellant through the valve. The following example of the invention are given as illustration. In the example the various ingredients of each composition are assigned a successive number (from 01 upwards) for greater ease of description. EXAMPLE RECTAL FOAM 0.02% BUDESONIDE % COMPOSITION (of foam or pressurized liquid) 01 Budesonide (active principle) 0.02 02 Methyl-p-hydroxybenzoate (bacteriostatic) 0.12 03 Propyl-p-hydroxybenzoate (bacteriostatic) 0.03 04 Polysorbate 20 (foaming surfactant) 4 05 Polyglycol 300 isostearate (foam thickener) 4 06 Propyleneglycol 5 07 Purified water 76.83 08 Freon 12 (propellant) 6.5 09 Freon 114 (propellant) 3.5 Preparation method: A) The components 01, 02 and 03 are dissolved in 07 in the stated order in a stainless steel dissolving vessel of suitable capacity fitted with a propeller stirrer and turboemulsifier. B) 04, 05, 06 and finally 01 are added while stirring, and the turboemulsifier is then operated for 15 minutes. C) Using a metering pump, the suspension is metered in the volume corresponding to the theoretical weight into aerosol cans while stirring. D) Each can is immediately sealed by clinching the dispenser valve and is then pressurized by means of the propellant, which is fed in under pressure in a suitable quantity by a pumping device. According to the present invention it has been experimentally found that the pharmaceutical compositions of the invention possess a surprising retrograde diffusion capacity. A composition according to the invention possesses retrograde diffusion tendentially greater than that of a Budesonide enema, or liquid dyster.

Claims: Claims for the following Contracting States : AT, BE, CH, LI, DE, DK, FR, GB, LU, SE, NL A pharmaceutical composition for the rectal administration of an active principle which exhibits a prevalently topical anti-inflammatory action with high retrograde diffusion along the colon tract, characterised in that said active principle is budesonide formulated in a fluid vehicle able to generate a foam on rectal administration, the volume of foam developed on administering a unit dose of said composition being not less than 100 ml. A pharmaceutical composition as claimed in claim 1, characterised by'being contained in a foam can. A pharmaceutical composition as claimed in claim 1, characterised by comprising said active principle in a fluid vehicle, at least one surfactant and a foaming propellant. A pharmaceutical composition as claimed in claim 2, characterised by also comprising an adjuvant for the active principle, such as a suspending or solubilising agent. A pharmaceutical composition as claimed in claim 2, characterised by also comprising a foam thickener. A pharmaceutical composition as claimed in claim 1, characterised by comprising budesonide, methyl-p-hydroxy-benzoate, propyl-p-hydroxy-benzoate, polysorbate, polyglycol isostearate, propylene glycol, purified water and freon. Claims for the following Contracting States : ES, GR A process for preparing a pharmaceutical composition for the rectal administration of an active principle which exhibits a prevalently topical anti-inflammatory action with high retrograde diffusion along the colon tract, characterised in that said active principle is budesonide and it is formulated in a fluid vehide able to generate a foam on rectal administration. A process as daimed in claim 1, characterised in that the volume of foam developed on administering unit dose of said composition is not less than 100 ml. A process as claimed in claim 1, characterised by providing said foam in a foam can. A process as claimed in claim 1, characterised by comprising said active priciple in a fluid vehicle, at least one surfactant and a foaming propellant. A process as claimed in claim 1, characterised by also comprising an adjuvant for the active principle, such as a suspending or solubilizing agent. A process as claimed in claim 1, characterised by also comprising a foam thickener. A process as claimed in daim 1, characterised by comprising budesonide, methyl-p-hydroxybenzoate, propyl-p-hydroxy-benzoate, polysorbate, polyglycol isostearate, propylene glycol, purified water and a propellant.

Inventors: BRUNETTI GABRIELE, CHIODINI EMILIA, FRIGERIO GIULIANO, GIORGETTI ENZO, BRUNETTI, GABRIELE, CHIODINI, EMILIA, FRIGERIO, GIULIANO, GIORGETTI, ENZO
Applicants: GIULIANI SPA, GIULIANI S.P.A.
Application year: 1991
Main classification: A61K9
IPC codes: A61K9, A61K36, A61K31, A61P1, A61K45, A61P31, A61P29