WO2003045353A1

WO2003045353A1 - Method for the preparation of pharmaceutical nanosuspensions using supersonic fluid flow

Info

Publication number: WO2003045353A1
Application number: PCT/GB2002/005187
Authority: WO
Inventors: Guy Vergnault; Pascal Grenier; Alain Nhamias; Samya Belaredj; Sabine Desset
Original assignee: Jagotec Ag; Bassil, Nicholas, Charles
Priority date: 2001-11-20
Filing date: 2002-11-19
Publication date: 2003-06-05
Also published as: AU2002343033A1; GB0127832D0

Abstract

A method of making a drug carrier is provided which comprises subjecting at least one solid therapeutically active compound dispersed in a solvent to high pressure in a supersonic fluid flow through a nozzle to form particles having an average diameter, determined by photon correlation spectroscopy (PCS) of 40 nm to 500 nm, the proportion of particles larger than 2µm in the total population being less than 0.1% (volume weighted determined by laser diffractometry ), wherein said active compound is solid at room temperature and is insoluble, only sparingly soluble or moderately soluble in water, aqueous media and/or organic solvents. Also provided are uses of apparatus in said methods and particles prepared according such methods or uses.

Description

METHOD FOR THE PREPARATION OF PHARMACEUTICAL NANOSUSPENSIONS USING SUPERSONIC FLUID FLOW

The present invention relates to a method for the preparation of pharmaceutical nanosuspensions which are particularly useful in formulations of drug substances that are only sparingly soluble or moderately soluble in water.

Nanosuspensions of poorly soluble drug substances are a means for enabling the preparation of pharmaceutical compositions that would otherwise be difficult to achieve. Examples of methods of preparation of such nanosuspensions include the use of a piston gap homogeniser (WO 96/14830). Such methods enable the production of particles having an average diameter, determined by photon correlation spectroscopy (PCS) of 10 nm to 1000 nm. However, there is a need for smaller particle sizes so as to permit the improved preparation of pharmaceutical formulations of poorly soluble drugs.

Devices used to prepare nanosuspensions have been described previously. Devices used for homogenisation to prepare emulsions, dispersions, liposomes and cell ruptures have also been described (WO 00/39056, US-A-5720551). These devices have not been used to prepare nanosuspensions as defined in US-A-5858410 and nor have they been suggested for such purposes (www.beei.com).

According to a first aspect of the invention there is provided a drug carrier comprising particles of at least one therapeutically active compound which is insoluble, only sparingly soluble or moderately soluble in water, aqueous media and/or organic solvents. The active ingredient is solid at room temperature and has an average diameter, determined by photon correlation spectroscopy (PCS) of 10 nm to 1,000 nm, the proportion of particles larger than 2μm in the total population being less than 0.1% (volume weighted determined with laser diffractometry). When the active compound is introduced into water, aqueous media and/or organic solvents, according to

Thomson-freundlich equation it has an increased saturation solubility and an increased rate of dissolution compared with micronized powders of the active compound prepared using a ball mill, a pearl mill or a jet mill when the solid particles have been comminuted using a supersonic fluid flow through a nozzle.

The nozzle through which passes the fluid at high velocity can also be defined as a supersonic jet nozzle. The process can be described as being carried out according to the supersonic jet stream principle. In a preferred embodiment of this aspect of the invention, the active ingredient is solid at room temperature and has an average diameter, determined by photon correlation spectroscopy (PCS) of 40 nm to 500 nm.

The active compound may comprise at least one compound selected from the group consisting of: analgesics, anaesthetics, antirheumatics, antiallergics, antibiotics, antiepileptics, antimycotics, calcium metabolism regulators, chemotherapeutics, corticoids, cytokines, cytostatics, dermatics, hypnotics, immunotherapuetics, local anaesthetics, metastasis inhibitors, migraine agents, ophthalmics, parathyroid hormones, psychotropics, sedatives, hypolipidaemics and sex hormones.

Preferably, the fluid has a velocity of greater than 332 metres per second / 1195 km/h), where the speed of sound is defined as 332 meters per second in air at 0°C. Suitable ranges of speed include, 1000 km/h to 4000 km/h, preferably, 2000 km h to 3000km/h.

The operating pressures can be calculated accordingly, so for a preferred velocity of 3000 km/h, pressure is 45000 psi. Suitable ranges for operating pressure are therefore 2,000 to 45,000 psi where the back pressure may be from 0 to 5,000 psi.

As the fluid is accelerated through the nozzle from virtually zero-velocity in an axial direction, the fluid containing particles is accelerated to a velocity exceeding 332 ms^"1. Suitable continuous fluid flow may be in the range of 60 litre/hour. Once through the nozzle, the sudden drop in pressure combined with the severe acceleration causes cavitation in the space within the nozzle. The diameter of the nozzle can be selected as appropriate for the speed/pressure desired, suitable nozzle diameters may be 0.381 μm (0.015 inch), 0.813μm (0.032 inch), or 0.127μm (0.005 inch). Suitable ranges include 0.9 μm to 0.05μm. The precise diameter can be selected to provide the desired pressure with respect to the capacity the pump moving the fluid.

The drug carriers are therefore prepared without the use of ultrasonic probes or ball or pearl mills, or a piston gap homogenizer or microfluidizer.

In certain embodiments, the drug carrier may be prepared using synthetic, semi- synthetic or naturally occurring surfactants in concentrations of 0.001-30%. It may be preferred to exclude the presence of organic solvents. Suitably, the proportion of the internal or drug phase, based on the total weight of said carrier, is in the range of from 0.1 to 50 wt. %, 0.5 to 25 wt.%, or 10 to 20 wt.%.

The active compound or active compounds formulated in the drug carrier are slightly soluble or insoluble in water or aqueous solutions. Generally, this can mean a water solubility of less than 2.5% or below, 1.5% or below, or 1% or below. The term "poorly soluble" is also widely understood in the art to represent solubility below about lOmg/ml (lOg/1 or 1%). The definitions of solubility terms from the British Pharmacopoeia 2001 (BP 2001) and the European Pharmacopoiea (Ph. Eur.) are as follows and the terms "solubility" and "partly soluble" are used in the present specification in conformity with the definitions given in the above references. Solubility is therefore defined as approximate solubility in water at a temperature of between 15°C and 25°C. The term partly soluble is used to describe a mixture of which only some of the components dissolve in water.

In some embodiments, the drug carrier may comprises one or more dispersion- stabilising substances. The dispersion-stabilising substances may be present in an amount of 0.001 to 20 wt. %, based on the total weight of said carrier. These substances may include, but are not limited to, compounds from the series consisting of poloxamers, poloxamines, ethoxylated mono-and diglycerides, ethoxylated lipids and lipoids, ethoxylated fatty alcohols and alkylphenols, ethoxylated fatty acid esters, polyglycerol ethers and esters, lecithins, esters and ethers of sugars or sugar alcohols with fatty acids or fatty alcohols, phospholipids and sphingolipids, sterols, esters or ethers thereof and mixtures of these compounds. Alternatively, the substances may comprise egg lecithin, soya lecithin or hydrogenated lecithin, mixtures thereof or mixtures of one or both lecithins with one or more phospholipid components, cholesterol, cholesterol palmitate, or stigmasterol.

The drug carriers may further comprising charge stabilisers, which may be present in an amount of 0.01 to 20 wt. %, based on the total weight of said carrier. The charge stabilisers may comprise dicetyl phosphate, phosphatidylglycerol, saturated or unsaturated fatty acids, sodium cholate, anti-flocculants or amino acids.

The drug carriers may further comprising one or more viscosity-increasing substances which may be present in an amount of 0.1 to 20 wt. %, based on the total weight of said carrier. The viscosity-increasing substances may comprise cellulose ethers and esters, polyvinyl alcohol, alginates, xanthans, pectins, polyacrylates, poloxamers and poloxamines. Other adjuvants may include a compound selected from the group consisting of sugars or sugar alcohols, glucose, mannose, trehalose, mannitol and sorbitol.

The drag carriers may also further comprising charge carriers. Suitably, the drug carriers are dispersed in distilled water or an aqueous medium or in an aqueous medium with additions of electrolytes, mono- and disaccharides, polyols or mixtures thereof. Such additions may include, but are not limited to sodium chloride, mannose, glucose, fructose, xylose, mannitol, sorbitol, xylitol and glycerol.

The particles which form the drug carriers may be lyophilised or spray dried as part of the process of preparation. The drug carriers may comprise additional active compounds. In the case of several active compounds, one active compound or several active compounds may be dissolved or dispersed in another or several others, adsorbed onto the surface thereof or dispersed as a solution in the particle. Suitably, the particles which form the drug carrier may be dispersed in a non-aqueous medium, which may be a liquid, semisolid or solid medium. The liquid medium may be a liquid oily medium which may comprise lipids or lipoids or mixtures thereof, such as mono-, di- or tiiglycerides, waxes, fatty alcohols and fatty alcohol esters, beeswax, oleyl oleate, isopropyl myristate, wool fat or mixtures thereof. Alternatively, the medium may comprise longer-chain organic molecules of polymers, of liquid, semisolid or solid polyethylene glycols, poloxamers, poloxamines or mixtures thereof.

According to a second aspect of the invention there is provided a drug carrier comprising particles of at least one therapeutically active compound which is insoluble, only sparingly soluble or moderately soluble in water, aqueous media and/or organic solvents. The active ingredient is solid at room temperature and has an average diameter, determined by photon correlation spectroscopy (PCS) of 40 nm to 500 nm, the proportion of particles larger than 2μm in the total population being less than 0.1% (volume weighted determined with laser diffractometry, the solid particles have been comminuted using a supersonic fluid flow through a nozzle.

According to a third aspect of the invention there is provided a drug carrier comprising particles of at least one therapeutically active compound which is insoluble, only sparingly soluble or moderately soluble in water, aqueous media and/or organic solvents. The active ingredient is solid at room temperature and has an average diameter, determined by photon correlation spectroscopy (PCS) of 10 nm to 1,000 nm, the proportion of particles larger than 2 μm in the total population being less than 0.1% (volume weighted determined by laser diffractometry), and, when introduced into water, aqueous media and/or organic solvents, the active compound having an increased saturation solubility and an increased rate of dissolution compared with micronized powders of the active compound prepared using a ball mill, a pearl mill or a jet mill, the solid particles having been comminuted by using cavitation or shearing and impact forces with introduction of a high amount of energy using a supersonic fluid flow through a nozzle. According to a fourth aspect of the invention there is provided a method of making a drug carrier comprising the steps of: subjecting at least one solid therapeutically active compound dispersed in a solvent to high pressure in a supersonic fluid flow through a nozzle to form particles having an average diameter, determined by photon correlation spectroscopy (PCS) of 10 nm to 1,000 nm, the proportion of particles larger than 2μm in the total population being less than 0.1% (volume weighted determined by laser diffractometry. The active compound is solid at room temperature and is insoluble, only sparingly soluble or moderately soluble in water, aqueous media and/or organic solvents. Suitably, when the active compound is introduced into water, aqueous media and/or organic solvents, according to Thomson-freundlich equation it has an increased saturation solubility and an increased rate of dissolution compared with micronized powders of the active compound prepared using a ball mill, a pearl mill or a jet mill when the solid particles have been comminuted using a supersonic fluid flow through a nozzle according to a method of the invention.

According to a fifth aspect of the invention there is provided the use of an apparatus comprising a nozzle arranged for delivering a coherent jet of fluid, and an elongated chamber having an open end for receiving said jet of fluid, a reflective surface at the other end of the chamber for reflecting the jet, and a mechanism for adjusting the distance from the reflective surface to the open end in the preparation of suspensions of particles having an average diameter, determined by photon correlation spectroscopy (PCS) of 10 nm to 1,000 nm, the proportion of particles larger than 2μm in the total population being less than 0.1% (volume weighted determined by laser diffractometry, wherein the fluid flow through the nozzle is a supersonic fluid flow.

In an alternative configuration of the apparatus, the following features may be included. Interchangeable reflective surfaces may be provided, each surface being suitable for a different application. A removable insert may be provided for insertion into the chamber at the open end, the insert having an orifice of a smaller dimension than the inner wall of the chamber. The removable inserts may be interchangeable so that each insert is suitable for a different application. In another construction, the apparatus may comprise two nozzles (or more), configured to deliver respective jets of fluid along two different paths, an elongated chamber that contains an interaction region in which the two paths meet. The chamber may be configured to form a stream of fluid from the two jets, the stream of fluid following a path that has essentially the opposite direction from one of the paths of one of the jets, thereby causing the jets kinetic energy to be absorbed by the fluid streams. Intense forces of shear, impact and/or cavitation break down the oil phase into extremely small and highly uniform droplets, and allows sufficient time for the emulsifier to interact with the oil droplets.

Alternatively, the nozzles may be aligned essentially opposite one another. The apparatus may also include an inlet port configured for receiving a second fluid, the inlet port aligned to position the received second fluid such that the jets cause shear and cavitation in the second fluid. The apparatus may include an outlet port configured to emit the stream. The apparatus may further include a port that may be configured to be either an inlet port or an outlet port.

Preferably the chamber of the above invention includes at least one reactor which may be interchangeable with other reactors having a different reactor characteristic, for example reactor inner diameter, reactor contour and reactor material composition. Preferably there is at least one seal positioned between the reactors which may be interchangeable with other seals having a different seal characteristic such as seal diameter.

A commercially available apparatus such as the DeBEE 2000 may be purchased from BEE (Best Emulsifying Equipment) International Ltd. at www.beei.com (Migdal Haemek, Israel). The DeBEE 2000 has an emulsifying cell consisting of a nozzle and a facing absorption cell. The emulsifying cell uses an extremely high velocity fluid jet, produced by the nozzle, which enters the absorption cell. The kinetic energy of the fluid jet is then translated into forces of shear, cavitation and/or impact, which break the processed products droplets. The geometry of the cell creates a second, high velocity fluid stream. The interaction between these two streams generates the forces, which act on the processed product. The dual feed emulsifying cell configuration enables introducing one or more of the processed product ingredients directly into the emulsifying cell. This feature is particularly useful for extremely hard, abrasive, or viscous materials, as well as for fast reacting products. The continuous phase of the processed product is fed into the emulsifying cell nozzle by the system's high pressure pump. The discontinuous phase of the product is fed into the emulsifying cell, downstream to the nozzle, by means of standard metering pump. The problems associated with introducing difficult materials into the high-pressure pump and through the nozzle are eliminated, while the process in the emulsifying cell is just as effective as with conventional feed.

Machines of this type are further described in WO 00/39056 and US 5,720,551 which contain descriptions of single or dual fluid flow apparatus.

Without being bound by theory, it is believed that the methods and uses described in accordance with the present invention are not dependent upon the precise construction of the apparatus used, but rather it is the flow of fluid at supersonic speeds through a nozzle to generate the forces of shear, impact and/or cavitation.

According to a sixth aspect of the invention there is provided the use of an apparatus comprising two nozzles configured to deliver respective jets of fluid along two different paths, and an elongated chamber that contains an interaction region in which the two paths meet, the chamber being configured to form a stream of fluid from the two jets, the stream of fluid following a path that has essentially the opposite direction from one of the paths of one of the jets to prepare a drug carrier comprising an active ingredient which is solid at room temperature and has an average diameter, determined by photon correlation spectroscopy (PCS) of lOnm to 1,000 nm, the proportion of particles larger than 2μm in the total population being less than 0.1% (volume weighted determined by laser diffractometry), wherein the fluid flow through the nozzle is a supersonic fluid flow.

According to a seventh aspect of the invention there is provided the use of an apparatus comprising a nozzle arranged for delivering a coherent jet of fluid, an elongated chamber having an open end for receiving said jet of fluid, a reflective surface at the other end of the chamber for reflecting the jet and, a mechanism for adjusting the distance from the reflective surface to the open end to prepare a drug carrier comprising an active ingredient which is solid at room temperature and has an average diameter, determined by photon correlation spectroscopy (PCS) of lOnm to l,000nm, the proportion of particles larger than 2μm in the total population being less then 0.1% (volume weighted determined by laser diffractometry), wherein the fluid flow through the nozzle is a supersonic fluid flow.

The fields of use for the medicament carriers according to the invention are diverse.

For example, they can be used for parenteral (in particular intravenous administration and for lymphatic absorption), enteral (in particular mucoadhesive drug forms), pulmonary and topical (nasal, dermal, intraocular) drug administration and for administration into body cavities.

Parenteral administration is:

1. Intravenous administration (targeting to the liver, spleen, bone marrow, lung and blood cells, such as lymphocytes, monocytes and granulocytes, generation of particles circulating in the blood with continuous dissolution of the active compound in the blood compartment).

2. Lymphatic absorption of medicament carriers by injection close to lymph vessels (targeting of cytostatics to lymph nodes).

3. -Intramuscular administration (depot form for prolonged or sustained release of active compounds, e.g. corticoids. Because of the reduced amount of fluid in the tissue, a retarded dissolving process occurs, above all with sparingly soluble to practically insoluble active compounds).

4. Intra-articular administration (e.g. for antirheumatics and immunosuppressives for arthritis).

5. Intracavital administration (e.g. cytostatics for forms of cancer in the peritoneum and in the pleural cavity).

6. Subcutaneous and intradermal administration (e.g. depot forms and cytostatics for skin cancer).

Enteral administration forms are used, in particular, for:

1. Increasing absorption by the preparation of mucoadhesive drug carriers which increasingly accumulate on the mucosa and also remain there longer.

2. Oral immunisation due to interaction of the drug carrier with e.g. M cells in Peyer's patches.

3. Absorption of active compounds via the M cells.

4. Increase in the absorption of lipophilic active compounds by non-specific accumulation on the mucosa, e.g. lipophilic vitamins.

5. Absorption of drag carriers into the lymphatic system.

Possible pulmonary administration forms are, in particular:

1. Aerosols, metered aerosols (spraying an aqueous dispersion of the drag carrier). 2. Aerosols, metered aerosols (spraying a powder, where the medicament carriers in the nanometer range have been sprayed onto carrier particles, such as lactose, in the micrometer range. The lactose dissolves in the lung, and releases the medicament carriers, e.g. for the purpose of absorption by macrophages, or e.g. they remain on the surface of the lung, and active compounds with the target group of peritoneal cells I or II dissolve).

3. Instillation of the dispersion, where substances which promote spreading, such as phospholipids or phospholipid-associated proteins, are possibly added.

Examples of topical use:

1. Dermatological medicaments for administration of e.g. corticoids and antimycotics. Due to the increased saturation solubility of the medicament carriers, a higher concentration gradient results than with active compound crystals in the micrometer range, and absorption into the skin is promoted. In addition, because of their small size, the drag carriers have the possibility of entering between the intermediate spaces of the stratum corneum cells (analogously to liposomes), which also promotes absorption into the skin.

2. Ophthalmic suspensions, ophthalmic gels or inserts, e.g. for pilocarpine or beta- blockers. Because of the particulate structure, prolonged residence times occur, as are already described for nanoparticles of polymers. Because of the slow solubility, the inserts have the effect of sustained release without using a control membrane.

3. Cosmetics analogous to liposomal preparations.

4. Particulate administration of active compounds into the nose for the purpose of nasal absorption. Examples of medicament groups which are to be processed in the form of a nanosuspension are (where appropriate in the form of the sparingly water-soluble form, e.g. as the base instead of the hydrochloride):

1. Analgesics/antirheumatics, e.g. morphine, codeine, piritramide, fentanyl, levomethadone, tramadol, diclofenac, ibuprofen, indomethacin, naproxen, piroxicam.

2. Antiallergics, e.g. pheniramine, dimethindene, terfenadine, astemizole, loratidine, doxylamine and meclozine.

3. Antibiotics/chemotherapeutics, e.g. rifampicin, ethambutol, thiacetazone.

4. Antiepileptics, e.g. carbamazepine, clonazepam, mesuximide, phenytoin, valproic acid.

5. Antimycotics a) internal: e.g. natamycin, amphotericin B, miconazole. b) external also: e.g. clotrimazole, econazole, fenticonazole, bifonazole, ketoconazole, tolnaftate.

6. Corticoids (internal preparations) e.g. aldosterone, fludrocortisone, betamethasone, dexamethasone, triamcinolone, fluocortolone, hydroxycortisone, prednisolone, prednylidene, cloprednol, methylprednisolone, spironolactone.

7. Dermatics

a) Antibiotics: e.g. tetracycline, erythromycin, framycetin, tyrothricin, fusidic acid.

b) Nirostatics as above, and also: e.g. vidarabine. c) Corticoids as above, and also: e.g. amcinonide, fluprednidene, alclometasone, clobetasol, diflorasone, halcinonide, fluocinolone, clocortolone, flumethasone, diflucortolone, fludroxycortide, halomethasone, desoximetasone, fluocinolide, fluocortin butyl, fluprednidene, prednicarbate, desonide.

8. Hypnotics, sedatives, e.g. cyclobarbital, pentobarbital, methaqualone, benzodiazepines, (flurazepam, midazolam, nitrazepam, lormetazepam, flunitrazepam, triazolam, brotizolam, temazepam, loprazolam)

9. Immunotherapeutics and cytokines, e.g. azathioprine, ciclosporin.

10. Local anaesthetics a) Internal: e.g. butanihcaine, mepivacaine, bupivacaine, etidocaine, lidocaine, articaine. b) External also: e.g. oxybuprocaine, tetracaine, benzocaine.

11. Migraine agents, e.g. lisuride, methysergide, dihydroergotamine, ergotamine.

12. Anaesthetics, e.g. methohexital, propofol, etomidate, ketamine, thiopental, droperidol, fentanyl.

13. Parathyroid hormones, calcium metabolism regulators e.g. dihydrotachysterol.

14. Ophthalmics, e.g. cyclodrin, cyclopentolate, homatropine, tropicamide, pholedrine, edoxudine, aciclovir, acetazolamide, diclofenamide, carteolol, timolol, metipranolol, betaxolol, pindolol, bupranolol, levobununol, carbachol.

15. Psychotropics, e.g. benzodiazepines (lorazepam, diazepam), clomethiazole. 16. Sex hormones and their inhibitors, e.g. anabolics, androgens, antiandrogens, gestagens, oestrogens, antioestrogens.

17. Cytostatics and metastasis inhibitors

a) alkylating agents, such as melphalan, carmustine, lomustine, cyclophosphamide, ifosfamide, trofosfamide, chlorambucil, busulphan, prednimustine, thiotepa

b) antimetabolites, such as fluorouracil, methotrexate, mercaptopurine, tioguanine

c) alkaloids, such as vinblastine, vincristine, vindesine

d) antibiotics, such as dactinomycin

e) taxol and related or analogous compounds

f) dacarbazine, oestramustine, etoposide.

18. Hypolipidaemic agents e.g. fibrates, such as bezafibrate, ciprofibrate, fenofibrate and gemfibrizol.

Preferred features for the second and subsequent aspects of the invention are as for the first aspect mutatis mutandis.

The invention will now be further described by way of reference to the following Examples which are provided for the purposes of illustration only and are not to be construed as being limiting on the invention. Example 1: Fenofibrate

The formulation is shown in the table below.

A) Preparation of the hot raw emulsion

The active drag (100 g) was melted at 95°C under magnetic stirring (IKA, 500 RPM).

The same quantity of water for injection was heated at 95°C under magnetic stirring.

The melted active drag was incorporated into the water at 95 °C with a high shear dispersing instrument (Ultra Turrax, 9000 rpm) until a homogenous emulsion was obtained.

B) Preparation of the nanosuspension (lOOOg)

The remaining water (800g) was fed into the Debee 2000 apparatus used in the Dual Feeding / Dual Jet configuration. In this configuration, water was forced through two nozzles at a pressure of 45000 psi corresponding to a velocity of 3000 km/h and forming a supersonic jet.

The resulting raw emulsion from Example 1(A) was incorporated using the Dual Feeding system. The emulsion was sucked up the feeding beaker thanks to the Nentury effect generated by the supersonic jet of water.

During one pass, the coarse drag particles are comminuted to nanoparticles because of the cavitation, shear forces and impact forces.

The intensity and volume average particle diameters (in nm), as measured by laser diffractometry (Νicomp), were:

The intensity, volume and number average particle sizes (in nm) as measured by PCS (Photon Correlation Spectroscopy-Nicomp) were:

Example 2: Fenofibrate

The DeBEE 2000 machine was used in dual jet/dual feeding mode

9420-050 Fenofibrate

78AN:Two litres of a 0.25% w/w Vitamin E TPGS aqueous solution were forced through two nozzles at a pressure of 45000 psi (3000 km/h velocity) to form two colliding supersonic fluid jets. The powdered active drug was sucked directly into the liquid phase by one of the jets . The resulting suspension containing 2.5 % of fenofibrate was recirculated into the 2 nozzles again at supersonic speed. After 2 cycles the particle size obtained had an average diameter of less than 1000 nm determined with PCS and less than 0.1% was greater than 2 μ for volume weighted determined with laser diffraction.

79 AN: In this example the active drug was melted prior to incorporation in one of the supersonic jet. Particle size results obtained were similar to those of the previous experiment.

82 AN: In this experiment, an aqueous dispersion of Phospholipon 6PL85 was forced through two nozzles at a pressure of 45000 psi (3000 km/h velocity) to form two colliding supersonic fluid jets. The powdered active drug was sucked directly into the liquid phase by one of the jets. The resulting suspension containing 5 % of fenofibrate was recirculated into the 2 nozzles again at supersonic speed. After 2 cycles the particle size obtained had an average diameter of less than 1000 nm determined with

PCS and less than 0.1% was greater than 2 μ for volume weighted determined with laser diffraction.

Example 3: Spironolactone

3011: Spironolactone

04 AN: In this experiment, an aqueous dispersion of Octowet 70 (30 %sodium doccusate solution in propylene glycol ) was forced through two nozzles at a pressure of 45000 psi (3000 km/h velocity) to form two colliding supersonic fluid jets. The powdered active drug was sucked directly into the liquid phase by one of the jets. The resulting suspension containing 5 % of fenofibrate was recirculated into the 2 nozzles again at supersonic speed. After 2 cycles the particle size obtained had an average diameter of less than 1000 nm, determined with PCS and less than 0.1% was greater than 2 μ for volume weighted determined with laser diffraction.

Claims

1. A drug carrier comprising particles of at least one therapeutically active compound which is insoluble, only sparingly soluble or moderately soluble in water, aqueous media and/or organic solvents, wherein the active ingredient is solid at room temperature and has an average diameter, determined by photon correlation spectroscopy (PCS) of 10 nm to 1,000 nm, the proportion of particles larger than 2μm in the total population being less than 0.1% (volume weighted determined with laser diffractometry), and, when introduced into water, aqueous media and/or organic solvents, according to the Thomson-Freundlich equation the active compound has an increased saturation solubility and an increased rate of dissolution compared with micronized powders of the active compound prepared using a ball mill, a pearl mill or a jet mill when the solid particles have been comminuted using a supersonic fluid flow through a nozzle.

2. Carrier according to claim 1, wherein the particles of the main population have an average diameter of between 40 and 500 nm.

3. Carrier according to claim 1 or claim 2, wherein said carrier is prepared using synthetic, semi-synthetic or naturally occurring surfactants in concentrations of 0.001- 30%.

4. Carrier according to any one of claims 1 to 3, wherein said carrier is prepared with exclusion of the use of organic solvents.

5. Carrier according to any one of claims 1 to 4, wherein the proportion of the internal or drug phase, based on the total weight of said carrier, is 0.1 to 50 wt. %.

6. Carrier according to any one of claims 1 to 5, wherein the drug caiτier comprises an active compound or active compounds which are partly soluble in water with a solubility of less than 2.5%.

7. Camer according to any one of claims 1 to 6, wherein said carrier comprises one or more dispersion or stabilising substances.

8. Carrier according to claim 7, wherein said carrier comprises the dispersion or stabilising substances in an amount of 0.001 to 20 wt. %, based on the total weight of said carrier.

9. Carrier according to claim 7 or claim 8, wherein the dispersion or stabilising substances are compounds from the series consisting of poloxamers, poloxamines, ethoxylated mono-and diglycerides, ethoxylated lipids and lipoids, ethoxylated fatty alcohols and alkyiphenols, ethoxylated fatty acid esters, polyglycerol ethers and esters, lecithins, esters and ethers of sugars or sugar alcohols with fatty acids or fatty alcohols, phospholipids and sphingolipids, sterols, esters or ethers thereof and mixtures of these compounds.

10. Carrier according to claim 7 or claim 8, wherein the stabilising substance comprises egg lecithin, soya lecithin or hydrogenated lecithin, mixtures thereof or mixtures of one or both lecithins with one or more phospholipid components, cholesterol, cholesterol palmitate, or stigmasterol.

11. Carrier according to any one of claims 1 to 10, further comprising charge stabilisers.

12. Carrier according to claim 11, further comprising charge stabilisers in an amount of 0.01 to 20 wt. %, based on the total weight of said carrier.

13. Carrier according to claim 11 or claim 12, wherein the charge stabilisers comprise dicetyl phosphate, phosphatidylglycerol, saturated or unsaturated fatty acids, sodium cholate, anti-flocculants or amino acids. i

14. Carrier according to any one of claims 1 to 13, further comprising one or more viscosity-increasing substances.

15. Carrier according to claim 14, further comprising viscosity-increasing substances in an amount of 0.1 to 20 wt. %, based on the total weight of said carrier.

16. Carrier according to claim 14 or claim 15, wherein the viscosity-increasing substances comprises cellulose ethers and esters, polyvinyl alcohol, alginates, xanthans, pectins, polyacrylates, poloxamers and poloxamines.

17. Carrier according to any one of claims 14 to 16, further comprising a compound selected from the group consisting of sugars or sugar alcohols, glucose, mannose, trehalose, mannitol and sorbitol.

18. Carrier according to any one of claims 1 to 17, characterised in that the particles are dispersed in distilled water or an aqueous medium or in an aqueous medium with additions of electrolytes, mono- and disaccharides, polyols or mixtures thereof.

19. Carrier according to claim 18, wherein the additions comprise sodium chloride, mannose, glucose, fructose, xylose, mannitol, sorbitol, xylitol and glycerol.

20. Carrier according to any one of claims 1 to 19, wherein the particles are lyophilised or spray dried.

21. Carrier according to any one of claims 1 to 20, further comprising one or more additional active compounds.

22. Carrier according to claim 21, wherein, in the case of several active compounds, one active compound or several active compounds are dissolved or dispersed in another or several others, adsorbed onto the surface thereof or dispersed as a solution in the particle.

23. Carrier according to any one of claims 1 to 22, wherein said particles arc dispersed in a non-aqueous medium.

24. Carrier according to claim 23, wherein said particles are dispersed in a liquid, semisolid or solid medium.

25. Carrier according to claim 23, wherein said particles are dispersed in a liquid oily medium.

26. Carrier according to claim 25, wherein the medium comprises lipids or lipoids or mixtures thereof.

27. Carrier according to claim 26, wherein the medium comprises mono-, di- or triglycerides, waxes, fatty alcohols and fatty alcohol esters, beeswax, oleyl oleate, isopropyl myri state, wool fat or mixtures thereof.

28. Carrier according to claim 26, wherein the medium comprises longer-chain organic molecules of polymers, of liquid, semisolid or solid polyethylene glycols, poloxamers, poloxamines or mixtures thereof.

29. Drug earner comprising particles of at least one therapeutically active compound which is insoluble, only sparingly soluble or moderately soluble in water, aqueous media and/or organic solvents, wherein the active ingredient is solid at room temperature and has an average diameter, determined by photon correlation spectroscopy (PCS) of 40 nm to 500 nm, the proportion of particles larger than 2μm in the total population being less than 0.1% (volume weighted determined with laser diffractometry, the solid particles have been comminuted using a supersonic fluid flow through a nozzle.

30. Drug carrier comprising particles of at least one therapeutically active compound which is insoluble, only sparingly soluble or moderately soluble in water, aqueous media and/or organic solvents, wherein the active ingredient is solid at room temperature and has an average diameter, determined by photon correlation spectroscopy (PCS) of 10 nm to 1,000 nm, the proportion of particles larger than 2 μ in the total population being less than 0.1% (volume weighted determined by laser diffractometry), and, when introduced into water, aqueous media and/or organic solvents, the active compound having an increased saturation solubility and an increased rate of dissolution compared with micronized powders of the active compound prepared using a ball mill, a pearl mill or a jet mill, the solid particles having been comminuted by using cavitation or shearing and impact forces with introduction of a high amount of energy using a supersonic fluid flow through a nozzle.

31. A drug carrier as claimed in any one of claims 1 to 30, wherein said active compound comprises at least one compound selected from the group consisting of analgesics, anaesthetics, antirheumatics, anti allergies, antibiotics, antiepileptics, antimycotics, calcium metabolism regulators, chemotherapeutics, corticoids, cytokines, cytostatics, dermatics, hypnotics, immunotherapuetics, local anaesthetics, metastasis inhibitors, migraine agents, ophthalmics, parathyroid hormones, psychotropics, sedatives, hypolipidaemics, and sex hormones.

32. A drug carrier according to claim 31, wherein said active compound comprises an analgesic selected from the group consisting of morphine, codeine, piritramide, fentanyl, levomethadone, tramadol, diclofenac, ibuprofen, indomethacin, naproxen, and piroxicam.

33. A drug carrier according to claim 31, wherein said active compound comprises an antiallergic selected from the group consisting of pheniramine, dimethindene, terfenadine, astemizole, loratidine, doxylaminc and meclozine.

34. A drug carrier according to claim 31, wherein said active compound comprises an antibiotic selected from the group consisting of rifampicin, ethambutol, and thiacetazone.

35. A drug earner according to claim 31, wherein said active compound comprises an antiepileptic selected from the group consisting of clonazepam, mesuximide, phenytoin, and valproic acid.

36. A drag carrier according to claim 31, wherein said active compound comprises an antimycotic selected from the group consisting of natamycin, amphotericin B, miconazole, clotrimazole, econazole, fenticonazole, bifonazole, ketoconazole, and tolnaftate.

37. A drug carrier according to claim 31, wherein said active compound comprises a corticoid selected from the group consisting of aldosterone, fludrocortisone, betamethasone, dexamethasone, triamcinolone, fluocortolone, hydroxycortisone, prednisolone, prednylidene, cloprednol and methylprednisolone.

38. A drug carrier according to claim 31 , wherein said active compound comprises a dermatic selected from the group consisting of tetracycline, erythromycin, framycGtin, tyrothricin, fusidic acid, vidarabine, amcinonide, fluprednidene, alclometasone, clobetasol, diflorasone, halcinonide, fluocinolone, clocortolone, flumethasone, diflucortolone, fludroxycortidc, halomethasone, desoximetasone, fluocinolide, fluocortin butyl, fluprednidene, prednicarbate and desonide.

39. A drug carrier according to claim 31, wherein said active compound comprises a hypnotic selected from the group consisting of cyclobarbital, pentobarbital, methaqualone and benzodiazepines.

40. A drug carrier according to claim 31, wherein said active compound comprises an immunotherapeutic selected from the group consisting of azathioprine and ciclosporin.

41. A drug carrier according to claim 31 , wherein said active compound comprises a local anaesthetic selected from the group consisting of butanihcaine, mepivacaine, bupivacaine, etidocaine, lidocaine, articaine, oxybuprocaine, tetracaine and benzocaine.

42. A drug carrier according to claim 31, wherein said active compound comprises a migraine agent selected from the group consisting of lisuride, methysergide, dihydroergotamine and ergotamine.

43. A drug carrier according to claim 31, wherein said active compound comprises an anaesthetic selected from the group consisting of methohexital, propofol, etomidate, ketamine, thiopental, droperidol and fentanyl.

44. A drug carrier according to claim 31, wherein said active compound comprises dihydrotachysterol.

45. A drug carrier according to claim 31, wherein said active compound comprises an ophthalmic selected from the group consisting of cyclodrin, cyclopentolate, homatropine, tropicamide, pholedrine, edoxudine, aciclovir, acetazolamide, diclofenamide, carteolol, timolol, metipranolol, betaxolol, pindolol, bupranolol, levobununol and carbachol.

46. A drug carrier according to claim 31, wherein said active compound comprises a psychotropic selected from the group consisting of benzodiazepines.

47. A drug carrier according to claim 31, wherein said active compound comprises a sex hormone selected from the group consisting of anabolics, androgens, antiandrogens, gestagens, oestrogens and antioestrogens.

48. A drug carrier according to claim 31, wherein said active compound comprises a cytostatics or metastasis inhibitors selected from the group consisting of alkylating agents, antimetabolites, alkaloids, antibiotics, taxol and dacarbazine.

49. A drug carrier according to claim 31, wherein the hypolipidaemic agent comprises bezafibrate, ciprofibrate, fenofibrate or gemfibrizol.

50. A method of making a drug carrier comprising subjecting at least one solid therapeutically active compound dispersed in a solvent to high pressure in a supersonic fluid flow through a nozzle to form particles having an average diameter, determined by photon correlation spectroscopy (PCS) of 40 nm to 500 nm, the proportion of particles larger than 2μm in the total population being less than 0.1% (volume weighted determined by laser diffractometry ), wherein said active compound is solid at room temperature and is insoluble, only sparingly soluble or moderately soluble in water, aqueous media and/or organic solvents.

51. The use of an apparatus comprising a nozzle arranged for delivering a coherent jet of fluid, and an elongated chamber having an open end for receiving said jet of fluid, a reflective surface at the other end of the chamber for reflecting the jet, and a mechanism for adjusting the distance from the reflective surface to the open end in the preparation of suspensions of particles having an average diameter, determined by photon correlation spectroscopy (PCS) of 10 nm to 1,000 nm, the proportion of particles larger than 2μm in the total population being less than 0.1% (volume weighted determined by laser diffractometry.

52. A use as claimed in claim 51, wherein the apparatus comprises two nozzles configured to deliver respective jets of fluid along two different paths

53. The use of an apparatus comprising two nozzles configured to deliver respective jets of fluid along two different paths, and an elongated chamber that contains an interaction region in which the two paths meet, the chamber being configured to form a stream of fluid from the two jets, the stream of fluid following a path that has essentially the opposite direction from one of the paths of one of the jets to prepare a drug carrier comprising an active ingredient which is solid at room temperature and has an average diameter, determined by photon correlation spectroscopy (PCS) of lOnm to 1,000 nm, the proportion of particles larger than 2μm in the total population being less than 0.1% (volume weighted determined by laser diffractometry).

54. The use of an apparatus comprising a nozzle arranged for delivering a coherent jet of fluid, an elongated chamber having an open end for receiving said jet of fluid, a reflective surface at the other end of the chamber for reflecting the jet and, a mechanism for adjusting the distance from the reflective surface to the open end to prepare a drug carrier comprising an active ingredient which is solid at room temperature and has an average diameter, determined by photon correlation spectroscopy (PCS) of lOnm to l,000nm, the proportion of particles larger than 2μm in the total population being less then 0.1% (volume weighted determined by laser diffractometry).