PCT
`INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT)
`(51) International Patent Classification 6 :
`
`WORLD INTELLECTUAL PROPERTY ORGANIZATION
`International Bureau
`
`(11) International Publication Number: (cid:9)
`
`WO 99/39700
`
`A61K 9/51, 38/23, 31/725, 31/12
`
`Al
`
`(43) International Publication Date: (cid:9)
`
`12 August 1999 (12.08.99)
`
`(21) International Application Number: (cid:9)
`
`PCT/EP99/00782
`
`(22) International Filing Date: (cid:9)
`
`5 February 1999 (05.02.99)
`
`(30) Priority Data:
`MI98A000234 (cid:9)
`
`6 February 1998 (06.02.98) (cid:9)
`
`IT
`
`(71) Applicant (for all designated States except US): VECTOR-
`PHARMA S.P.A. [IT/IT]; Via del Follatoio, 12, 1-34148
`Trieste (IT).
`
`(72) Inventors; and
`(75) Inventors/Applicants (for US only): ESPOSITO, Pierandrea
`[IT/IT]; Via Montona, 4, 1-34100 Trieste (IT). COLOMBO,
`Italo [IT/IT]; Via Don Sturzo, 15, 1-20065 Inzago (IT).
`COCEANI, Nicoletta [IT/IT]; Via Firmano, 10, 1-33043
`Cividale (IT). DEL CURTO, Maria, Dorly [IT/IT]; Via
`Oratorio, 4, 1-27050 Corvino Sanquirico (IT). CARLI, Fabio
`[IT/IT]; Salita Cedassammare, 3/1, 1-34136 Trieste (IT).
`
`(74) Agent: GERVASI, Gemma; Notarbartolo & Gervasi S.p.A.,
`Corso di Porta Vittoria, 9, 1-20122 Milan (IT).
`
`(81) Designated States: AL, AM, AT, AU, AZ, BA, BB, BG, BR,
`BY, CA, CH, CN, CU, CZ, DE, DK, EE, ES, FI, GB, GD,
`GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, KE, KG, KP,
`KR, KZ, LC, LK, LR, LS, LT, LU, LV, MD, MG, MK,
`MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG,
`SI, SK, SL, TJ, TM, TR, TT, UA, UG, US, UZ, VN, YU,
`ZW, ARIPO patent (GH, GM, KE, LS, MW, SD, SZ, UG,
`ZW), Eurasian patent (AM, AZ, BY, KG, KZ, MD, RU, TJ,
`TM), European patent (AT, BE, CH, CY, DE, DK, ES, FI,
`FR, GB, GR, IE, IT, LU, MC, NL, PT, SE), OAPI patent
`(BF, BJ, CF, CG, CI, CM, GA, GN, GW, ML, MR, NE,
`SN, TD, TG).
`
`Published
`With international search report.
`Before the expiration of the time limit for amending the
`claims and to be republished in the event of the receipt of
`amendments.
`
`(54) Title: PHARMACEUTICAL COMPOSITIONS IN FORM OF NANOPARTICLES COMPRISING LIPIDIC SUBSTANCES AND
`AMPHIPHILIC SUBSTANCES AND RELATED PREPARATION PROCESS
`
`(57) Abstract
`
`Pharmaceutical compositions in form of nanoparticles comprising a composite material, consisting of at least one lipidic substance
`and of at least one amphiphilic substance, and of a pharmaceutically active principle. Said compositions, thanks to the surface and mass
`properties of said composite material, show an improvement in the incorporation of the active principles and an increase in the bioavailability
`of the poorly absorbable active principles.
`
`Exhibit 1024
`ARGENTUM
`IPR2018-00080
`
`000001
`
`

`

`FOR THE PURPOSES OF INFORMATION ONLY
`
`Codes used to identify States party to the PCT on the front pages of pamphlets publishing international applications under the PCT.
`
`AL
`AM
`AT
`AU
`AZ
`BA
`BB
`BE
`BF
`BG
`BJ
`BR
`BY
`CA
`CF
`CG
`CH
`CI
`CM
`CN
`CU
`CZ
`DE
`DK
`EE
`
`Albania
`Armenia
`Austria
`Australia
`Azerbaijan
`Bosnia and Herzegovina
`Barbados
`Belgium
`Burkina Faso
`Bulgaria
`Benin
`Brazil
`Belarus
`Canada
`Central African Republic
`Congo
`Switzerland
`Cote d'Ivoire
`Cameroon
`China
`Cuba
`Czech Republic
`Germany
`Denmark
`Estonia
`
`ES
`Fl
`FR
`GA
`GB
`GE
`GH
`GN
`GR
`HU
`IE
`IL
`IS
`IT
`JP
`KE
`KG
`KP
`
`KR
`KZ
`LC
`LI
`LK
`LR
`
`Spain
`Finland
`France
`Gabon
`United Kingdom
`Georgia
`Ghana
`Guinea
`Greece
`Hungary
`Ireland
`Israel
`Iceland
`Italy
`Japan
`Kenya
`Kyrgyzstan
`Democratic People's
`Republic of Korea
`Republic of Korea
`Kazakstan
`Saint Lucia
`Liechtenstein
`Sri Lanka
`Liberia
`
`LS
`LT
`LU
`LV
`MC
`MD
`MG
`MK
`
`ML
`MN
`MR
`MW
`MX
`NE
`NL
`NO
`NZ
`PL
`PT
`RO
`RU
`SD
`SE
`SG
`
`Lesotho
`Lithuania
`Luxembourg
`Latvia
`Monaco
`Republic of Moldova
`Madagascar
`The former Yugoslav
`Republic of Macedonia
`Mali
`Mongolia
`Mauritania
`Malawi
`Mexico
`Niger
`Netherlands
`Norway
`New Zealand
`Poland
`Portugal
`Romania
`Russian Federation
`Sudan
`Sweden
`Singapore
`
`SI
`SK
`SN
`SZ
`TD
`TG
`TJ
`TM
`TR
`TT
`UA
`UG
`US
`UZ
`VN
`YU
`ZW
`
`Slovenia
`Slovakia
`Senegal
`Swaziland
`Chad
`Togo
`Tajikistan
`Turkmenistan
`Turkey
`Trinidad and Tobago
`Ukraine
`Uganda
`United States of America
`Uzbekistan
`Viet Nam
`Yugoslavia
`Zimbabwe
`
`000002
`
`

`

`WO 99/39700 (cid:9)
`
`PCT/EP99/00782
`
`1
`
`PHARMACEUTICAL COMPOSITIONS IN FORM OF NANOPARTICLES
`
`COMPRISING LIPIDIC SUBSTANCES AND AMPHIPHILIC SUBSTANCES AND
`
`RELATED PREPARATION PROCESS
`Prior art
`
`5 (cid:9)
`
`In the research field of the new vehicles suitable to the administration of active
`
`principles, a great interest has been directed towards the polymeric systems
`
`having size in the micrometer range and to the polymeric systems having size in
`
`the nanometer range.
`
`Among the mostly used polymers the polyalkylcyanoacrylates and the poly-lactic
`
`10 (cid:9)
`
`acid (PLA) and poly-lactic glycolic acid (PLA-PLGA) derivatives are to remember.
`
`Such systems show however some disadvantages.
`
`For example the polyalkylcyanoacrylates are metabolized by the organism in a 24
`
`hours interval and release formaldehyde, a potentially toxic derivative; the PLA
`
`and PLA-PLGA polymers do not produce toxic metabolites but they have long
`
`15 (cid:9)
`
`degradation times ranging from some weeks to some months, and then they may
`
`show dangerous accumulation phenomena.
`
`Moreover, the preparation methods of these systems need the use of potentially
`
`toxic organic solvents which may remain in traces in the final form.
`
`In the end, the size of the majority of said systems exclude their use for
`
`20
`
`intravenous way because extraneous bodies having size higher than 5 ptm
`
`injected in vein may cause embolisms.
`
`These negative aspects generated greater attention for administration systems
`
`having greater biocompatibility and lower toxicity: the first among all these are the
`
`lipidic colloidal systems such as oil/water emulsions, liposomes, lipidic micro- and
`
`25
`
`nanoparticles.
`
`Oil/water emulsions, consisting of lipidic droplets having size in the range of
`
`nanometers, dispersed in an external aqueous phase, have been used as a
`
`vehicle for the parenteral feeding (JP Patent No. 55,476, 1979, Okamota, Tsuda
`
`and Yokoama).
`
`30 (cid:9) Oil/water emulsions containing active principles have been described in the Patent
`
`WO 91/02517, 1991, Davis and Washington. Such systems have a high capacity
`
`000003
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`

`

`WO 99/39700 (cid:9)
`
`PCT/EP99/00782
`
`2
`
`to incorporate active principles in the internal lipidic phase, but the active
`
`principles easily diffuse from such phase towards the external phase originating
`
`stability problems and limitations for the optional development of a protracted
`
`release form.
`
`5 The liposomes are colloidal structures having an aqueous internal phase
`
`sorrounded by one or more layers of phospholipids. The use of liposomes as
`
`vehicles for the administration of drugs is described for example in the U.S. Patent
`
`No. 3,993,754 (1976, Rahman and Cerny).
`
`However typically, such systems show stability problems during the stocking, a
`
`10 (cid:9)
`
`poorly reproducible preparation method and a low potentiality to incorporate and
`
`retain active principles.
`
`Fountain and others invented lipidic microparticles in globular form having size
`
`ranging from 0.5 ?Am to 100 µm as vehicles for the administration of active
`
`principles. Such invention is disclosed in the U.S. Patent No. 4,610,868 (1986).
`
`15 (cid:9) Domb and others (US Patent 435,546) invented the LiposheresTM, insoluble
`
`particles having size about equal to 40 µm, suspended in an aqueous
`
`environment, consisting of a lipophilic internal phase surrounded by external
`
`layers of phospholipids, added to the composition and adsorbed on the surface of
`
`the particles themselves. These systems were developed for the controlled
`
`20 (cid:9)
`
`release of anaesthetic drugs (Domb and others, US Patent 5227165) and of active
`
`principles having insecticide and pesticide activity (Domb and others US Patent
`
`5227535). However the technique for the preparation of such systems requires the
`
`help of solvents which remain in traces in the final form.
`
`The per os administration turns out to be difficult for active principles which are not
`
`25 (cid:9) much soluble, not much absorbed in the gastroenteric tract or which are sensible
`
`to the pH or the action of the proteolytic enzymes (proteins and peptides). The
`
`incorporation of such substances in lipidic nanoparticles allows to overcome such
`
`difficulties because these nanoparticle systems may be absorbed along the
`
`gastrointestinal tract. Their reduced size allow to exploit the mechanisms of the
`
`30 (cid:9)
`
`passive transmucosal absorption, or to pass through the intercellular junctions or
`
`the ionic channels or to use the endocytosis mechanism or to enter the lymphatic
`
`000004
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`

`

`WO 99/39700 (cid:9)
`
`PCT/EP99/00782
`
`flux.
`
`3
`
`Solid lipidic systems consisting of nanopellets were developed by Speiser and
`
`others (US Patent 4,880,634, 1989), and destined to the oral administration of
`
`poorly absorbed drugs. The lipidic pellets are prepared emulsifying lipidic
`
`5 (cid:9)
`
`substances in an aqueous environment with a high energy mixer, then cooling the
`
`emulsion at room temperature and obtaining the pellets by sonication.
`
`Gasco (EP 0526666A1, 05/08/1991) invented a technique for the preparation of
`
`lipidic nanoparticles. A microemulsion is prepared adding to an aqueous phase a
`
`lipid melted in the presence of surfactants and cosurfactants, which is then
`
`io (cid:9)
`
`dispersed in an aqueous environment maintained at a temperature around 10 °C.
`
`The solid nanoparticles are obtained in an aqueous suspension, but may be
`
`subsequently deprived of the residual surfactants by ultrafiltration and recovered
`
`by filtration or freeze-drying.
`
`Such technique turns out to be advantageous from the point of view of the saving
`
`15 (cid:9)
`
`of energy with respect to the high energy homogenization, it allows to obtain
`
`smaller nanoparticles, having average diameters ranging from 90 nm to 900 nm,
`
`with a more uniform size distribution and a low polydispersion index. However the
`
`preparation of a microemulsion needs the melting of the lipidic material which is
`
`for most used lipidic substances about 70 °C, which limits the use of such
`
`20 (cid:9)
`
`technique for the thermolable substances.
`
`Summary of the invention
`
`The invention relates to pharmaceutical compositions in form of nanoparticles,
`
`having a diameter lower than 1000 nm and preferably ranging from 50 to 500 nm,
`
`comprising a composite material, consisting of at least one lipidic substance and
`
`25 (cid:9)
`
`at least one amphiphilic substance, and a pharmaceutically active principle.
`
`We have unexpectedly found that, operating according to the present invention,
`
`said composite material and the relative particles have characteristics not
`
`achievable by an usual mixing of a lipidic substance with an amphiphilic substance
`
`or by the adsorption of an amphiphilic substance on lipidic particles.
`
`30 (cid:9)
`
`The amphiphilic substance may be preferentially distributed on the surface of the
`
`nanoparticles or it may be preferentially distributed inside the nanoparticles or it
`
`000005
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`

`

`WO 99/39700 (cid:9)
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`PCT/EP99/00782
`
`4
`
`may be homogeneously distributed on the surface of and inside the nanoparticles.
`
`The formation of the composite material allows to obtain nanoparticles:
`
`1. with surface characteristics helping the oral administration absorption and the
`
`half-life time in the circulatory system;
`
`5
`
`2. with mass characteristics, as the low melting temperature, allowing to
`
`incorporate thermolable drugs;
`
`3. suitable, thanks to the presence of lipophilic zones and partially hydrophilic
`
`zones in the composite material, to the vehiculation both of hydrosoluble drugs
`
`and of liposoluble drugs;
`
`10 (cid:9)
`
`4. able to homogeneously incorporate the hydrophilic drugs (for example peptides)
`
`inside an essentially lipophilic matrix.
`Detailed description of the invention
`
`The invention relates to the preparation of compositions for pharmaceutical use in
`
`form of particles having size lower than one micrometer (nanoparticles),
`
`15 (cid:9)
`
`comprising a composite material consisting of lipidic and amphiphilic substances,
`
`the latter being of lipidic or polymeric kind.
`
`Generally, the nanoparticles according to the invention are prepared starting from
`
`a composite material obtained by comelting or cosolubilization of the lipidic
`
`material and the amphiphilic substances. The comelted mixture, at the subsequent
`
`20 (cid:9)
`
`cooling, results in a composite material having new characteristics with respect to
`
`the two starting materials, showing more hydrophilic zones and more lipophilic
`
`zones thanks to the reciprocal disposition of the components or to the segregation
`
`of the amphiphilic material towards the surface or inwards the mass of the
`
`nanoparticles. These characteristics are substantially different from the surface
`
`25 (cid:9)
`
`adsorption of an amphiphilic substance on a lipophilic surface. Such properties will
`
`be described in detail in the Characterization Examples reported below.
`
`The drug may be dissolved or suspended in said comelted mixture during the
`
`preparation process and, thanks to the new properties of the composite material, it
`
`may divide, according to its characteristics, preferentially inside the more
`
`30 (cid:9)
`
`hydrophilic areas or the more lipophilic areas. Moreover, the hydrophilic drugs (for
`
`example peptides) charged on the nanoparticles turn out to be unexpectedly
`
`000006
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`

`

`WO 99/39700 (cid:9)
`
`PCT/EP99/00782
`
`5
`
`distributed in an homogeneous way inside the nanoparticles themselves while the
`
`peptide fraction adsorbed on the surface turns out to be very low, and lower with
`
`respect to the Examples of the prior art (particles consisting of lipidic core and
`
`adsorbed amphiphilic substance).
`
`5 The nanoparticles obtained from the comelted mixture maintain the same
`
`characteristics of the starting composite material.
`
`The nanoparticles may be obtained with different preparation techniques:
`
`- 1. a technique providing for the dispersion of a oil in water microemulsion
`
`(consisting of, as oil phase, lipidic and amphiphilic materials kept at a temperature
`
`io higher than the melting point of the composite mixture and one or more
`
`surfactants and cosurfactants) in an aqueous medium, utilising the temperature
`
`gradient.
`
`- 2. A technique providing for the high pressure homogenization of a fine emulsion
`
`of a composite material, at a temperature higher than the melting temperature of
`
`is (cid:9)
`
`the materials forming the composite, or of a fine suspension of a composite
`
`material, below the melting temperature of the composite, in presence of
`
`surfactant agents.
`
`The preparation of the invention according to the microemulsion-dispersion
`
`process (technique 1), provides for the initial comelting or cosolubilization of two
`
`20 (cid:9)
`
`or more lipidic and amphiphilic components, taken to the melting temperature of
`
`the components themselves or at least to the melting of one of the two
`
`components, when the latter is soluble in the former; an appropriate volume of an
`
`aqueous solution containing ore or more surfactants and cosurfactants, warmed at
`
`the same temperature of the composite material melted, under mild stirring is
`
`25 (cid:9)
`
`added to such melted composite material.
`
`It is also possible to form the microemulsion simultaneously taking to the melting
`
`temperature the lipidic and amphiphilic components in presence of the water and
`
`the surfactants and cosurfactants needed to formation of the microemulsion itself.
`
`The active pharmaceutical principle may be dissolved or dispersed in the starting
`
`30 (cid:9) melted composite material or added directly to the microemulsion during the
`
`preparation of the microemulsion itself, depending on the properties of the active
`
`000007
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`WO 99/39700
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`PCT/EP99/00782
`
`6
`
`principle itself. The distribution of the active principle occurs into the composite
`
`material, allowing an unexpected decrease of the drug amount adsorbed on the
`
`surface and submitted to the degradating action of the enzymes and of the
`external environment.
`
`5 The so formed oil/water microemulsion is subsequently dispersed in water or in
`
`aqueous medium, in controlled volume and stirring conditions, at a temperature
`
`generally ranging from +1° to +10 °C, but that may also range from -15 to -30 °C
`
`using non aqueous solvents miscible with water, originating in this way the
`
`composite nanoparticles in solid form in aqueous suspension. Said nanoparticles
`
`io (cid:9)
`
`have a diameter lower than 1000 nm. The nanoparticles turn out to be different
`
`with respect to the systems obtained by the techniques of amphiphilic substances
`
`adsorption on the surface of the lipidic particles (Domb) or by the use of
`
`amphiphilic substances as surfactants for the formation of lipidic nanoparticles
`
`(Gasco).
`
`15 Subsequently, the nanoparticle suspensions may be washed with water or
`
`aqueous solutions through an ultrafiltration system (or dialysis) which allows to
`
`remove the surfactant, cosurfactant and free drug excess. Therefore such process
`
`allows to remove the undesired possible effects due to the surfactants presence in
`
`the pharmaceutical form. Moreover, with such a procedure it is possible to
`
`20 (cid:9)
`
`quantitatively determine the percentage of the active principle not incorporated or
`
`adsorbed on the nanoparticles.
`
`The composition described above may be administered as an aqueous
`
`suspension or it is recovered as a solid by freeze-drying, filtration, evaporation of
`
`the aqueous solvent or spray-drying techniques.
`
`25 The nanoparticles according to the present invention have the following
`
`quantitative composition by weight:
`
`- lipidic substances from 0.5 to 99.5%, and preferably from 10% to 90%;
`
`amphiphilic substances from 0.5 to 99.5% and preferably from 10% to 90%;
`
`- pharmacologically active principle from 0.001 to 99%, and preferably from 0.01%
`
`30
`
`to 50% with respect to the sum of the lipidic substances and amphiphilic
`
`substances.
`
`000008
`
`(cid:9)
`

`

`WO 99/39700 (cid:9)
`
`PCT/EP99/00782
`
`7
`
`In the preparation process of the nanoparticles according to the technique (1), the
`
`component substances are used in the following proportions by weight:
`in the microemulsion:
`
`- lipidic components, from 0.1% to 50% by weight and preferably from 10 to 25%;
`
`5 (cid:9)
`
`- amphiphilic components, from 0.1% to 50% by weight and preferably from 0.5%
`to 25%;
`
`- surfactants, from 5% to 30% and preferably from 10% to 20%;
`
`- cosurfactants, from 0% to 15% and preferably from 3% to 7%;
`
`- water, or aqueous solutions, from 40% to 75% by weight and preferably from
`
`10 (cid:9)
`
`50c/0 to 70%;
`
`- pharmaceutical active principles, directly incorporated in the composite material
`
`or dissolved in the microemulsion, in concentrations variable on the base of the
`
`incorporation efficacy and of the desired dosages and ranging from 0.001% to
`
`99% and preferably from 0.001% to 50% by weight with respect to the sum of the
`
`15 (cid:9)
`
`lipidic components and amphiphilic components.
`
`In the dispersion:
`
`- the microemulsion prepared as described above is dispersed in aqueous
`
`environment (water or aqueous solutions) with volumetric dilutions from 1:2 to
`
`1:200, preferably from 1:5 to 1:50.
`
`20 (cid:9)
`
`To the dispersion
`
`- coadjuvants of the dispersion, from 0.05% to 5% by weight;
`
`- viscosizing agents, of polymeric kind, from 0.05% to 5% by weight
`
`may be added.
`
`The preparation according to the high pressure homogenization technique
`
`25 (cid:9)
`
`(technique 2) provides for the dispersion of the composite material, added with
`
`one or more adjuvant substances, in an aqueous environment. The composite
`
`material is homogenized to form nanoparticles maintaining the system at the
`
`melting temperature of the material itself or just below such temperature
`
`("softening") or at temperatures maintaining the composite material at the solid
`
`30
`
`state.
`
`The composite material may be initially prepared by comelting or cosolubilization,
`
`000009
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`

`

`WO 99/39700 (cid:9)
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`PCT/EP99/00782
`
`8
`
`analogously to what is reported for the technique 1, proceeding to the comelting of
`
`two or more lipidic and amphiphilic components taken to the melting temperature
`
`of the components themselves or at least to the melting of one of the two
`
`components when the latter is soluble in the former.
`
`5 (cid:9)
`
`The composite material may be preliminarly dispersed in an aqueous solution
`
`containing surfactant substances, stabilizing substances and/or viscosizing
`
`substances by dispersion or low energy homogenization techniques (for example
`
`using Silverson L2R or Ultra-Turrax kind equipments). After such treatment, which
`
`may be not necessary if the composite material shows surface characteristics
`
`10 (cid:9)
`
`such as to help its dispersion in water, the system is submitted to high pressure
`
`homogenizator (for example of APV Gaulin, APV Rannie Mini-Lab, Microfluidizer
`
`kind) to repeated homogenization cycles which cause nanoparticle dispersions.
`
`The high pressure homogenization treatment may occur at the composite material
`
`melting temperature, at "softening" temperature or at temperatures at which the
`
`15 (cid:9) material is present in a solid state in micronized form.
`
`The active principle may be comelted, dissolved or dispersed in the composite
`
`material or in each of its constituents during the comelting of the system, or added
`
`during the subsequent process phases, as it is or in presence of surfactants which
`
`helps its incorporation in the nanoparticles or the adsorption on their surface.
`
`20 Subsequently, the nanoparticle suspensions may be washed with water or
`
`aqueous solutions, analogously to what is described for the technique (1), through
`
`a ultrafiltration system.
`
`Analogously, the composition may be administered as aqueous suspension or
`
`recovered as a solid by freeze-drying, filtration or aqueous solvent evaporation or
`
`25 (cid:9)
`
`spray-drying techniques.
`
`In the preparation process of the nanospheres according to the technique (2), the
`
`substances composing the invention are used in the following proportions by
`
`weight:
`
`- lipidic components, from 0.1% to 50% by weight, preferably from 0.5 to 15%;
`
`30 (cid:9)
`
`- amphiphilic components, from 0.1% to 50%, preferably from 0.5% to 15%;
`
`- surfactants, from 0.05% to 10%, preferably from 0.5% to 5%;
`
`000010
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`

`

`WO 99/39700 (cid:9)
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`PCT/EP99/00782
`
`9
`
`- water, or aqueous solutions of hydrosoluble components, from 45% to 99.5%,
`preferably from 50% to 80%;
`
`- dispersion coadjuvants from 0.05% to 5%;
`
`viscosizing agents, of polymeric kind from 0.05% to 1%;
`
`5 (cid:9)
`
`- pharmaceutical active principles, directly incorporated in the composite material
`
`or dissolved in the microemulsion, in concentrations variable on the base of the
`
`incorporation efficacy and of the desired dosages, and ranging from 0.001% to
`
`99.9% and preferably from 0.001% to 50% by weight with respect to the sum of
`
`the lipidic components and the amphiphilic components.
`
`lo (cid:9)
`
`Among the lipidic materials usable according to the invention we can mention both
`
`natural products and synthetic or semi-synthetic kind products definable as "fats"
`
`in that they are not miscible or only partially miscible with water:
`
`1) natural fats either saturated or unsaturated and partially or totally hydrogenated
`
`vegetal oils, for example hydrogenated cotton oil (LubritabTM), hydrogenated palm
`
`15 (cid:9)
`
`oil (Dynasan TM P60) and hydrogenated soy-bean oil (SterotexTM HM);
`
`2) semi-synthetic and synthetic mono-, di- and triglycerides containing saturated
`
`and/or unsaturated fatty acids (having aliphatic chain length ranging from Cio to
`
`C22) and their polyhydroxyethylated derivatives, for example tristearine, caprico-
`
`caprylic triglycerides (MygliolTM, CaptexTM, LabrafacTM Lipo), behenic triglycerides
`
`20
`
`(CompritolTM) monoglycerides as glyceril monostearate (MyvaplexTM 600) or
`
`glyceril palmitostearate (PrecirolTM) and saturated or unsaturated polyhydroxylated
`
`triglycerides (series of LabrafilTM, LabrafacTM Hydro, Gelucire Tm);
`
`3) "liquid waxes", for example isopropyl myristate, isopropyl-caprinate, -caprylate, -
`
`laurate, -palmitate, -stearate and esters of fatty acids, such as ethyl oleate and
`
`25 (cid:9)
`
`oleyl oleate;
`
`4) "solid waxes", for example carnauba wax and bees-wax;
`
`aliphatic alcohols, for example cetyl alcohol, stearyl alcohol, lauryl alcohol,
`
`cetylstearyl alcohol and their polyhydroxyethylated derivatives;
`
`6) aliphatic carboxylic acids preferably having medium and long chain (C10-C22),
`
`30 (cid:9)
`
`saturated (decanoic acid, lauric acid, palmitic, stearic, docosanoic acid, etc.),
`
`unsaturated (oleic, linoleic, etc.) and their polyhydroxyethylated derivatives.
`
`000011
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`WO 99/39700
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`PCT/EP99/00782
`
`10
`
`Among the amphiphilic materials of lipidic kind one can use lipids having in their
`
`structure some hydrophilic components, such as for example:
`
`1) phospholipids belonging to the series: phosphatidyl glycerol,
`
`phosphatidylcholine and phosphatidic acid (e.g. dimiristoyl phosphatidyl glycerol);
`
`2) mono- and di-glycerides such as glyceril monostearate (MyvaplexTM 600) or
`
`glyceril palmitostearate (PrecirolTM);
`
`3) triglycerides and saturated or unsaturated polyhydroxylated triglycerides (e.g.
`
`series of LabrafilTM, LabrafacTM Hydro, GelucireTM);
`
`4) esters of fatty acids, such as decylester of oleic acid: CetiolTM V and
`
`10
`
`isopropylmyristate;
`
`5) medium chain fatty acids (such as capric, caproic and lauric acids).
`
`Among the amphiphilic materials of polymeric kind, polymers may be used such
`
`as:
`
`1) Polyethylene glycols (PEG), both liquid (from PEG 200 to PEG 1000) and solid
`
`15 (cid:9)
`
`(from PEG 1500 to PEG 20,000);
`
`2) poly-(propyleneoxide) poly-(ethyleneoxide) copolymers, Poloxamer (LutrolTM
`
`188, LutrolTM 407);
`
`3) Polyvinyl alcohol;
`
`4) Polyacrylates (CarbopolTM, PemulenTM, NoveonTM);
`
`20 (cid:9)
`
`5) Poly-(methylvinyl ether) -maleic anhydride (GantrezTM) copolymers;
`
`6) Polysaccharides of natural origin such as chitosan and derivatives, ialuronic
`
`acid and derivatives, xanthan, scleroglucan, gellan, guar gum, locust bean gum,
`
`alginate and dextran;
`
`7) Polyesters such as for example poly-c-caprolactone.
`
`25 As reported above the composite materials according to the invention may be
`
`prepared by mixing, comelting or cosolubilization of the components selected
`
`among the lipidic materials and among the amphiphilic materials of lipidic or
`
`polymeric kind. For example, composite materials according to the invention, may
`
`be formed from mixtures of fatty acids (stearic acid-decanoic acid), of fatty acids
`
`30 (cid:9)
`
`and phospholipids (stearic acid-dimiristoyl phosphatidyl glycerol or dimiristoyl
`
`phosphatidylcholine), fatty acids and triglycerides or polyhydroxylated triglycerides
`
`000012
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`(cid:9)
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`WO 99/39700 (cid:9)
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`PCT/EP99/00782
`
`11
`
`(stearic acid and LabrafilTM 2130), mono- or di-glycerides with fatty acids (glyceril
`
`palmitostearate with stearic acid), fatty acids with polyethylene glycol (stearic acid-
`
`PEG), mono and diglycerides with copolymers of polyethylene oxide-
`
`polypropylene oxide (glycerilpalmitostearate with poloxamer).
`
`5 As aqueous phases according to the invention (aqueous phase of the
`
`microemulsion according to the technique 1 and/or dispersing phase according to
`
`the techniques 1 and 2) may be mentioned:
`
`1) water as it is or buffered at different pH and ionic strength;
`
`2) aqueous solutions of hydrophilic, hydrosoluble or hydrodispersable polymers
`
`10
`
`such as polyethylene glycol, polyvinyl pyrrolidone, polyacrylic acids and
`
`derivatives (e.g. Carbopol®, Pemulen®, etc.), polymethacrylic acids and
`
`derivatives (e.g. Eudragit®), copolymers of polyoxyethylene-polyoxypropilene (e.g.
`
`Poloxamer, Lutrol®), polysaccharides of various nature such as for example
`
`dextran, xanthan, scleroglucan, gum arabic, guar gum, chitosan, cellulose and
`
`15 (cid:9)
`
`starch derivatives;
`
`3) aqueous solutions of saccharides (e.g. sorbitol, mannitol, xylitol);
`
`3) mono or polyhydroxylic aliphatic alcohols, preferably having short chain (C2-
`
`C4);
`
`4) polyethylene glycols (e.g. PEG 200, PEG 400, PEG 600, PEG 1000);
`
`20 (cid:9)
`
`5) polyglycolic glycerides (e.g. LabrasolTM);
`
`6) polyglycols, such as for example propylene glycol, tetraglycol, ethoxydiglycol
`
`(Transcutolni).
`
`Among the surfactants, to use in techniques 1 and 2, we may not exhaustively
`
`mention all the non ionic surfactants with a HLB value generally but non
`
`25 (cid:9)
`
`necessarily greater than 7, such as for example: sorbitan-esters of fatty acids (e.g.
`
`Span®, Arlacel®, Brij®), polyoxyethylen sorbitan esters of fatty acids (e.g.
`
`Tween®, Capmul®, Liposorb®), copolymers of polypropileneoxide-
`
`polyethyleneoxide (Poloxamer), esters of polyethylene glycol (PEG)-glycerol
`
`(Labrasol®, Labrafil® with HLB 6-7), esters of PEG and acids or long chain
`
`30 (cid:9)
`
`aliphatic alcohols (e.g. Cremophor®), polyglycerid esters (Plurol®), esters of
`
`saccharides and fatty acids (sucro-esters). When needed, even anionic
`
`000013
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`WO 99/39700 (cid:9)
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`PCT/EP99/00782
`
`12
`
`surfactants (e.g. sodium lauryl sulfate, sodium stearate, sodium oleate), bile salts
`
`(e.g. sodium glycocholate, taurodeoxycholate, taurocholate, ursodeoxycholate) or
`cationic (e.g. tricetol), as well as low HLB surfactants, lecithins as they are (Lipoid
`S75) and hydrogenated (e.g. Lipoid S75, S75-3), phospholipids and their
`
`5 (cid:9)
`
`semisynthetic or synthetic derivatives may be used.
`
`Among the cosurfactants needed for the formation of the microemulsion we
`
`remember short chain alcohols such as for example ethanol, 2-propanol, n-
`
`butanol, isopropanol; short and medium aliphatic acids (e.g. butyric acid, valeric
`
`and capronic acids), aromatic alcohols (e.g. benzyl alcohol); medium chain
`
`10 (cid:9)
`
`alcohols and aliphatic acids (C8-C12) such as decanoic acid, lauric acid, caprynil
`
`alcohol and lauryl alcohol. Moreover, as cosurfactants may be used also esters or
`
`ethers of acids or medium-long chain aliphatic alcohols with mono- or
`
`polyhydroxylated alcohols. Some of the components mentioned among the
`
`cosurfactants may at the same time form the oil phase of the microemulsion.
`
`15 The pharmaceutical active principles usable in the invention may be both
`
`hydrosoluble (e.g. peptides or proteins) and liposoluble (e.g. steroidal hormones),
`
`as well as poorly soluble in both vehicles (e.g. acyclovir). The surface and mass
`
`properties of the nanoparticles according to the invention allow important
`
`advantages such as for example:
`
`20 (cid:9)
`
`1) the possibility of administering by oral or transmucosal way molecules usually
`
`not absorbable by such a way (e.g. polypeptides and proteins);
`
`2) the possibility of administering by oral and/or parenteral way lipophilic highly
`
`insoluble and poorly absorbable molecules;
`
`3) an improvement in the biopharmaceutical properties of the active principles
`
`25 (cid:9)
`
`(e.g. controlled or prolonged release and increase of the plasmatic half-life time);
`
`4) the possibility of administering by topical way molecules active at the mucosal
`
`or dermal level (e.g. antiviral, antimicotic, antipsoriatic drugs);
`
`5) the possibility of encapsulating active principles having unpleasant flavour,
`
`administrable in immediate release formulations.
`
`30 (cid:9)
`
`The active principle groups which may be advantaged from the invention include:
`
`non steroidal (NSAID) and steroidal (SAID) anti-inflammatories, estrogenic or
`
`000014
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`

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`WO 99/39700 (cid:9)
`
`PCT/EP99/00782
`
`13
`
`progestational (cid:9)
`
`antivirals, (cid:9)
`cardiovasculars, (cid:9)
`antimycotics,
`antineoplastics, hypolipidemics, peptides and proteins having different action.
`
`hormones, (cid:9)
`
`Among said active principles we may mention, however as a not exhaustive
`
`example:
`
`5 ergot alkaloids and derivatives: dihydroergotamine, didhydroergotoxine and
`
`bromocriptine.
`
`Analgesics and non steroidal anti-inflammatories, and their salts: diclofenac
`
`sodium, diclofenac hydroxyethil pyrrolidine, diclofenac diethylamine, ibuprofen,
`
`flurbiprofen, ketoprofen, indomethacin, mefenamic acid, naproxen, nimesulide and
`
`10 piroxicam.
`
`Antiarrhythmics: amiodarone, diisopyramide, propranolol and verapamil.
`
`Antibactericals: amoxicillin, flucloxacillin, gentamicin, rifam