Method for coating pharmaceutical substrates

Abstract

The present invention relates to the field of coating pharmaceutical substrates. In particular, the invention relates to methods of coating of pharmaceutical substances, pharmaceutical ingredients or a blend of them. The invention also provides a method of making a pharmaceutical formulation which maybe processed into a pharmaceutical dosage form, which utilizes solid pharmaceutical particles and a pharmaceutical formulation obtained by the method. The methods of the invention utilize atomic layer deposition technology. The novel methods allow difficult, moisture sensitive and electrically charged pharmaceutical substrates to be easily processable.

1 . A method of coating a pharmaceutical substrate, characterized by:
 providing a pharmaceutical substrate, which is a particle in a solid form;   and depositing a coating layer over the pharmaceutical substrate by atomic layer deposition method (ALD method).   
     
     
         2 . The method of  claim 1 , characterized in that the pharmaceutical substrate comprises at least one active pharmaceutical substance, pharmaceutical ingredient, or a blend of them. 
     
     
         3 . A method of  claim 1  or  2 , characterized in that the coating layer comprises of one or more different inorganic or organic materials or a combination of them. 
     
     
         4 . A method of  claim 3 , characterized in that the inorganic material comprises a metal oxide, preferably aluminum oxide Al 2 O 3  or titanium oxide TiO 2 . 
     
     
         5 . A method of  claim 3 , characterized in that the organic material comprises of taste-masking agents. 
     
     
         6 . A method of  claim 5 , characterized in that the tastemasking agent is a sweetener. 
     
     
         7 . A method of  claim 6 , characterized in that the tastemasking agent is a sugar alcohol. 
     
     
         8 . A method of making a pharmaceutical formulation, the method comprising:
 coating a pharmaceutical substrate by ALD;   optionally forming a mixture of the coated pharmaceutical substrate with excipients;   and   processing the mixture into a dosage form, which utilizes solid pharmaceutical particles.   
     
     
         9 . A method of  claim 8 , wherein processing of the mixture is performed by compressing. 
     
     
         10 . A method of  claim 9 , wherein the mixture is compressed into a tablet. 
     
     
         11 . A pharmaceutical formulation, wherein a pharmaceutical substrate is distributed as particles, and wherein a coating layer is deposited by ALD and the coating layer conformally coats over the individual particles of the pharmaceutical substrate. 
     
     
         12 . A pharmaceutical formulation of  claim 11 , which is in a dosage form, which utilizes solid pharmaceutical particles. 
     
     
         13 . A pharmaceutical formulation of  claim 12 , which is a tablet. 
     
     
         14 . Use of the ALD method for coating a pharmaceutical substrate, which is a particle.