HU224988B1 - Process for the production of powdered pulmonary surfactant preparations - Google Patents

Description

The present invention relates to the preparation of powdered lung surfactant compositions.

The lungs of all vertebrates contain a mixture of substances called 'lung surfactants'. This mixture has surfactant properties and reduces surface tension in the alveolar region of the lungs to such an extent that collapse of the final respiratory tract can be avoided upon exhalation. Said mixture of materials dynamically controls the surface tension, thereby avoiding the expected collapse of small lung bladders in favor of large lung bladders under the Laplace Law by the appropriate adjustment of the surface tension. As a result, a well-balanced, histologically and physiologically stable lung structure is formed.

The lung surfactants are shown in Table II. type alveolar pneumocytes are excreted in the form of lamellar bodies. They are compact units of phospholipid bilayers containing a high proportion of dipalmitoyl phosphatidylcholine (DPPC) and phosphatidylglycerol (PG). Other important components of the lung surfactants are the proteins SP-A, SP-B and SP-C. SP-A is a large molecule glycoprotein that plays a crucial role in the regulation of secretion.

The hydrophobic SP-C protein, and to a lesser extent the hydrophobic SP-B protein, plays the role of a "thermodynamic catalyst" in the formation of the monomolecular surface film (in the narrower sense). The presence of these proteins accelerates the spread kinetics to an extremely large extent. Only in this way can the surfactant mixture adapt to the current surface tension requirements without delay. These properties are reflected in the extreme hydrophobic nature of proteins, especially SP-C.

The lungs of premature babies are not or insufficiently capable of producing surfactants, and this leads to life-threatening oxygen deficiency ("IRDS") (Infant Respiratory Distress Syndrome). In preterm infants, IRDS is considered to be the leading cause of death.

It has been a proven practice for many years to treat IRDS by administering a lung surfactant formulation to the lungs of children to be treated. Lung surfactant formulations are known to be clinically effective in the treatment of ARDS (Aduit Respiratory Distress Syndrom), including ALI (Acute Lung Injury).

Lung surfactant formulations can be recovered from animal lungs by costly extraction and centrifugation (pulmonary rinsing) processes or by reconstitution of the individual components.

WO 92/06703 discloses the preparation of synthetic lung surfactant formulations. The process involves evaporating a chloroform solution containing phospholipids [e.g., dipalmitoylphosphatidylcholine (DPPC) and dioleyl phosphatidylethanolamine (DOPE)] and cholesterol in a rotary evaporator to a thin film, which is optionally buffered with appropriate proteins.

According to WO 91/00871, an organic solution of a lung surfactant composition containing a genetically engineered lung surfactant protein is rehydrated with a buffer and then lyophilized. The resulting lyophilisate has the disadvantage that it must be rehydrated at 37 ° C for 15 minutes prior to administration, which is cumbersome for the user and also a source of error.

According to the process described in European Patent 0 119 056, all components are dissolved in an organic solvent to produce lung surfactant formulations, the resulting solution is evaporated to dryness in vacuo, the residue is resuspended in an aqueous medium for an extended period of time and the resulting suspension freeze-dried. This process is also extremely expensive from a technical point of view.

According to German Patent Publication No. 3,229,179, a protein-free lung surfactant composition is prepared by dissolving the components in glacial acetic acid and freeze-drying the resulting solution. The disadvantage of the process is that the application of glacial vinegar requires complex security measures.

According to European Patent 0 655 237, pharmaceutical formulations for administration by inhalation in the form of suspension aerosols are prepared by spray drying from ethanol-water mixtures. This process is suitable, inter alia, for the preparation of compositions containing hydrophilic proteins (e.g., ecatibant acetate, human insulin and buzerelin acetate).

SUMMARY OF THE INVENTION It is an object of the present invention to provide a process which produces the least costly and advantageously storage stable product for the production of protein-containing powdered lung surfactant compositions containing hydrophobic lung surfactant proteins.

Surprisingly, it has been found that the above object can be achieved by spray drying an organic solution or suspension containing hydrophobic lung surfactant proteins and optionally further components.

The product of the present invention is stable for storage over a long period of time and can be resuspended at no expense before use. A particular advantage of the powder obtained is the small particle size (1-5 µm) which enables inhalation administration. The above aspect of the invention is of particular importance in the use of a pulmonary surfactant composition as a carrier for a drug for pulmonary delivery.

It is extremely surprising and, to the best of our knowledge, it cannot be explained that the temperature-sensitive components of the lung surfactants are partially resistant to the conditions of the spray drying process. For example, it is known that "SP-C" lung surfactant protein aggregates very rapidly at temperatures above -20 ° C and is thus inactivated. In contrast, this protein does not undergo any noticeable degradation in the spray drying process of the present invention and produces a loose powder that can be stored at room temperature.

HU 224 988 Β1

The present invention relates to a process comprising spray drying an organic solution or suspension containing hydrophobic lung surfactant proteins and optionally further components.

Further objects of the present invention are described in the claims.

Hydrophobic lung surfactant proteins include both natural and synthetic (including genetically engineered) proteins, particularly SP-B and SP-C, and mixtures thereof. The term "synthetic protein" also includes proteins whose amino acid sequence differs to a lesser or greater extent from naturally occurring lung surfactant proteins, including synthetic proteins with fully independent amino acid sequences designed with respect to lung surfactant properties (see, e.g., / 22315 (synthetic proteins). These proteins can be isolated, synthesized and purified by known methods.

For the preparation of organic solutions or suspensions according to the invention, alcohols (e.g. methanol, ethanol, 1-propanol, 2-propanol, butanols), chlorinated hydrocarbons (e.g. dichloromethane, chloroform etc.), acetone, ethers, hydrocarbons (e.g. benzene, toluene) are used. and mixtures thereof. The solvent may also contain water to mix with water. The upper water content is 25% by weight, preferably 5-15% by weight. The choice of the most suitable solvent or mixture of solvents for the pulmonary surfactant mixture to be dried is within the skill of the art in light of the skill of the art in spray drying and, if necessary, by conventional experimentation.

Lung surfactant formulations may contain conventional substances (e.g., especially phospholipids, carboxylic acids and buffering agents) as additional components.

The solution may be filtered through a sterile filter prior to spray drying. Spray drying is carried out in a manner known per se. Known procedures are described in detail in K. Masters, Spray Drying Handbook, 5th Edition (1991) and J. Broadhead, S. K. Edmond Rónán, C. T. Rhodes, The Spray Drying of Pharmaceuticals, Drug Dev. Ind. Pharm. 18, 1169 (1992). Spray drying is based on the principle that the solution or suspension of the product to be dried is dispersed into fine droplets and dried under a hot stream of gas. The solids remaining after evaporation of the solvent are separated from the gas stream by means of a cyclone and / or filter unit and collected.

Suitable solvents according to the invention are alcohols and chlorinated hydrocarbons (especially methanol, ethanol, 2-propanol and chloroform) and mixtures thereof, optionally with the addition of a smaller amount of water (up to 25% by weight). In particular, air and nitrogen may be considered as drying gas.

The inlet temperature of the gas is 60-200 ° C, preferably 90-150 ° C. The outlet temperature of the gas is maintained at 40-80 ° C, preferably 50-70 ° C by appropriate control of the atomization power and / or gas volume.

The following examples further illustrate the invention without limiting the invention to the examples.

Production examples

Example 1

7.0 g of 1,2-dipalmitoyl-3-sn-phosphatidylcholine, 2.5 g of 1-palmitoyl-2-oleoyl-3-sn-phosphatidylglycerol sodium, 205 mg of calcium chloride dihydrate and 250 mg Palmitic acid was dissolved in 300 ml of a 85:15 ethanol-water mixture at 60 ° C. The solution was cooled to room temperature and mixed with a solution of SP-C 9: 1 chloroform: methanol (350 mL; c = 429 mg / mL). The resulting solution was spray-dried in a Büchi B 191 laboratory spray-drying apparatus. Spray drying conditions: dryer gas air; inlet temperature 90 'C; exit temperature 52-54 ° C. We get a loose port.

Example 2

A solution of bovine lung surfactant (obtained by extraction and purification steps, for example, as described in European Patent 406,732) with chloroform-methanol is spray-dried under the following conditions: Büchi B 191 Laboratory Staple Dryer; drying gas nitrogen; inlet temperature 80 'C; exit temperature 50-52 ° C. A fine yellow powder is obtained.

Example 3

10.95 g of 1,2-dipalmitoyl-3-sn-phosphatidylcholine, 4.6 g of 1-palmitoyl-2-oleoyl-3-sn-phosphatidylglycerol ammonium, 418 mg of calcium chloride dihydrate and 750 mg Palmitic acid was dissolved at 50 ° C in 330 mL of 2: propanol / water (85:15), and after cooling to 30 ° C, SP-C solution (620 mL, 95: 5 in isopropanol / water) (c = 484 mg) / liter). The resulting solution was spray dried in a Büchi B 191 laboratory spray dryer. Drying conditions: drying gas nitrogen; inlet temperature 100 ° C; exit temperature 58-60 'C. A colorless powder is obtained.

Example 4

3.74 g (5.1 mmol) of 1,2-dipalmitoyl-3-sn-phosphatidylcholine, 2.81 g (3.7 mmol) of 1-palmitoyl-2-oloyl-3-snphosphatidylcholine, 2, 9 g (3.9 mmol) of 1,2-dipalmitoyl phosphatidyl-3-sn-phosphatidyl glycerol sodium, 2.34 mg of palmitic acid and 2.79 mg (1.9 mmol) of calcium chloride dihydrate in 160 ml 85:15 2-propanol / water at 50 ° C and after cooling to 30 ° C with a solution of SP-C in 566 ml of a 92: 8 isopropanol / water mixture (c = 330 mg / liter) at 30 ° C. mix. The resulting solution was spray dried in a Büchi B 191 laboratory spray dryer. Spraying Condition3

EN 224 988 Β1: drying gas nitrogen; inlet temperature 90 ° C; exit temperature 58-60 ° C. A colorless powder is obtained.

Example 5

0.5 g of RLLLLRLLLLRLLLLRLLLLR (R = Arg, L = Leu), 7.125 g of 1,2-dipalmitoyl-3-sn-phosphatidylcholine and 2.43 g of 1-palmitoyl-2-oleoyl-3-sn-phosphatidyl glycerol-ammonium was dissolved in 500 ml of 1: 1 chloroform-methanol with heating at 45 ° C and then spray-dried in a Büchi B 191 laboratory spray dryer. Spraying conditions: drying gas nitrogen; inlet temperature 85 ° C; exit temperature 55 ° C. A colorless powder is obtained.

Claims (13)

PATENT CLAIMS A process for the preparation of a pulmonary surfactant composition comprising a hydrophobic lung surfactant protein, wherein the organic solution or suspension containing hydrophobic lung surfactant proteins and optionally further components is spray dried. 2. The method of claim 1, wherein the organic solution or suspension of the hydrophobic lung surfactant proteins SP-C and / or SP-B is used. 3. A process according to claim 2, wherein the organic solution or suspension of SP-C is used. The process of claim 1, wherein the organic solution or suspension is 5-15% by weight of water. 5. A process according to claim 1 wherein the further component is phospholipids. 6. The process of claim 1, wherein the spray drying is performed in a heated gas. 7. A process according to claim 6 wherein the gas is air or nitrogen. The process of claim 6, wherein the gas is introduced at an inlet temperature of 60-200 ° C and an outlet temperature of 40-80 ° C. 9. The process of claim 7, wherein the gas is introduced at an inlet temperature of 90-150 ° C and an outlet temperature of 50-70 ° C. 10. A powdered lung surfactant composition according to any one of claims 1-9. A process according to any one of claims 1 to 6. 11. The powdered lung surfactant composition of claim 10 having a particle size of 1-5 µm. A lung surfactant composition according to claim 10 or 11 for administration by inhalation. Use of a lung surfactant composition according to claim 10 or 11 for the manufacture of a medicament for inhalation administration.