Hydroxyapatite tissue filler and its preparation and use

Abstract

The invention pertains to a biocompatible composition, suitable for use in soft or hard tissue augmentation, wherein the composition is an aqueous suspension containing a carrier fraction of ceramic particles of less than 15 μm and an augmentation fraction of ceramic particles of at least 20 μm. The ceramics typically comprise calcium phosphate. The composition is a may be used in soft tissue repair as well as hard bone replacement. It advantageously avoids the need for foreign body materials which are conventionally applied to stabilize augmentation suspensions.

1 . An injectable, biocompatible aqueous suspension with ceramic augmentation particles having a size of 20 microns to 4 mm and 15-45 wt % ceramic carrier particles with 20-500 nm, wherein the sum of augmentation particles and carrier particles amounts to 30-75 wt % of the composition, said composition comprising 25-75 wt % water and optionally at least one therapeutic agent, and wherein the weight ratio of said augmentation particles to said carrier particles in said composition in a weight ratio of 0.5:1 to 10:1. 
     
     
         2 . The composition according to  claim 1 , wherein said composition comprises 10-60 vol % augmentation particles. 
     
     
         3 . The composition according to  claim 2 , wherein said ceramic particles comprise calcium phosphate. 
     
     
         4 . The composition according to  claim 1 , wherein said carrier particles have a size between 100 and 500 nm. 
     
     
         5 . The composition according to  claim 1 , wherein said carrier particles have a size between 25 and 300 nm. 
     
     
         6 . The composition according to  claim 1 , wherein the suspension is sterile. 
     
     
         7 . The composition according to  claim 1 , comprising 15-38 wt % of said carrier particles. 
     
     
         8 . The composition according to  claim 1 , wherein said carrier fraction comprises hydroxyapatite (HA) and/or tricalcium phosphate (TCP). 
     
     
         9 . The composition according to  claim 1 , wherein said augmentation particles have a size between 20 and 100 μm. 
     
     
         10 . The composition according to  claim 1 , wherein said augmentation particles have a size between 100 μm and 4 mm. 
     
     
         11 . The composition according to  claim 1 , wherein said augmentation particles comprise calcium phosphate, calcium silicate, calcium carbonate or fluorides. 
     
     
         12 . The composition according to  claim 11 , wherein said augmentation particles comprise hydroxyapatite (HA), fluorapatite, octacalcium phosphate and tricalcium phosphate (TCP). 
     
     
         13 . The composition according to  claim 1 , wherein said composition comprises 20-40 vol % augmentation particles. 
     
     
         14 . The composition according to  claim 1 , being free from resorbable lubricants. 
     
     
         15 . The composition according to  claim 1 , wherein said therapeutic agent is selected from at least one therapeutic substance selected from the group consisting of an anti-inflammation agent, an antibacterial agent, an antifungal agent, an anti-histamine agent, a cell adhesion promoter, a local anesthetic agent and an osteoinductive factor. 
     
     
         16 . The composition according to  claim 1 , comprising up to 5 wt % of therapeutic agents. 
     
     
         17 . The composition according to  claim 1 , said augmentation particles having a surface porosity of less than 30%. 
     
     
         18 . A method of treatment comprising introducing to a mammal's body the composition according to  claim 1 . 
     
     
         19 . The method according to  claim 18 , for hard tissue augmentation, and bone regeneration. 
     
     
         20 . An injectable, biocompatible aqueous suspension with ceramic augmentation particles having a size of 20 microns to 4 mm and ceramic carrier particles with 20-500 nm, wherein the sum of augmentation particles and carrier particles amounts to 30-75 wt % of the composition, said composition comprising 25-75 wt % water and optionally at least one therapeutic agent, wherein the weight ratio of said augmentation particles to said carrier particles in said composition in a weight ratio of 0.5:1 to 10:1, and wherein said composition comprises 10-60 vol % augmentation particles. 
     
     
         21 . The composition according to  claim 20 , wherein said composition comprises 20-40 vol % augmentation particles.