Process of preparing aqueous suspension of chloramphenicol palmitate

Claim 2

A PROCESS FOR THE PREPARATION OF A BITTERLESS AQUEOUS SUSPENSION CONTAINING UNIFORM ALPHA-TYPE CRYSTALS OF CHLORAMPHENICOL PALMITATE WHICH COMPRISES MELTING FROM 1 TO 20 PARTS CHLOROAMPHENICOL PALMITATE ALONE AT A TEMPERATURE OF FROM 90*-95*C, MIXING THE MELT WITH AN AQUEOUS SOLUTION CONTAINING FROM 0.05 TO 10 PARTS OF ONE OR MORE PHARMACEUTICALLY ACCEPTABLE DISPERSING AGENTS SELECTED FROM THE GROUP CONSISTING OF POLYVINYL ALCHOL, POLYVINYLPYRROLIDONE, HYDROXYPROPYLCELLULOSE, SODIUM CARBOXYMETHYLCELLULOSE, HYDROXYPROPYL METHYLCELLULOSE, GUM ARABIC, CARBOXYVINYL POLYMER, POLYETHYLENE GLYCOLS, PROPYLENE GLYCOL, SORBITAN FATTY ACID ESTERS, POLYOXYETHYLENE SORBITAN FATTY ACID ESTERS, POLYOXYETHYLENE FATTY ACID ESTERS, SUCROSE FATTY ACID SARCOSINATES AND 70 TO 99 PARTS FATTY ACID ESTERS, SUCROSE FATTY ACID ESTERS ALKYL SULFATES, DIAL YLSULFOSUCCINATES AND FATTY ACID SARCOSINATES AND 70 TO 99 PARTS WATER AT A TEMPERATURE OF FROM 60*C TO THE MELTING POINT OF THE CHLORAMPHENICOL PALMITATE, COOLING THE RESULTING DISPERSION TO ROOM TEMPERATURE AND THEREAFTER REHEATING THE THUS COOLED DISPERSION TO A TEMPERATURE OF FROM 40* TO 60*C TO OBTAIN ALPHA-TYPE CRYSTALS OF CHLORAMPHENICOL PALMITATE HAVING AN AVERAGE PARTICLE DIAMETER OF FROM 0.06 TO 0.19 MICRONS.

Claim 3

A process for the preparation of a bitterless aqueous suspension containing uniform alpha-type crystals of chloramphenicol palmitate which comprises melting from 1 to 20 PARTS chloramphenicol palmitate at a temperature of 90* to 95*C, mixing the melt with an aqueous solution containing from 0.05 to 10 parts of one or more pharmaceutically acceptable dispersing agents selected from the group consisting of polyvinyl alcohol, polyvinylpyrrolidone, hydroxypropylcellulose, sodium carboxymethylcellulose, hydroxypropyl methylcellulose, gum arabic, carboxyvinyl polymer, polyethylene glycols, propylene glycol, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene fatty acid esters, polyoxyethylene castor oil derivatives, glyceryl fatty acid esters, sucrose fatty acid esters, alkyl sulfates, dialkylsulfosuccinates and fatty acid sarcosinates and 70 to 99 parts water at a temperature of from 60*C to the melting point of the chloramphenicol, cooling the resulting dispersion to room temperature, adding to the dispersion an aqueous solution containing 1 to 10 parts based on the total parts of the aqueous solution of one or more pharmaceutically acceptable surface active agents selected from the group consisting of sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene fatty acid esters, polyoxyethylene castor oil derivatives, glyceryl fatty acid esters, sucrose fatty acid esters, alkly sulfates, dialkylsulfosuccinates and fatty acid sarcosinates and reheating the resulting dispersion to a temperature of from 40* to 60*C to obtain alpha-type crystals of chloramphenicol palmitate having an average particle diameter of from 0.06 to 0.19 microns.

Claim 4

A process for the preparation of a bitterless aqueous suspension containing uniform alpha-type crystals of chloramphenicol palmitate which comprises melting from 1 to 20 PARTS chloramphenicol palmitate at a temperature of 90* to 95*C, mixing the melt with an aqueous solution containing from 0.05 to 10 parts of one or more pharmaceutically acceptable dispersing agents selected from the group consisting of polyvinyl alcohol, polyvinylpyrrolidone, hydroxypropylcellulose, sodium carboxymethylcellulose, hydroxypropyl methylcellulose, gum arabic, carboxyvinyl polymer, polyethylene glycols, propylene glycol, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene fatty acid esters, polyoxyethylene castor oil derivatives, glyceryl fatty acid esters, sucrose fatty acid esters, alkyl sulfates, dialkylsulfosuccinates and fatty acid sarcosinates and 70 to 99 parts water at a temperature of from 60*C to the melting point of the chloramphenicol, cooling the resulting dispersion to room temperature, adding to the dispersion an aqueous solution containing 1 to 10 parts based on the total parts of the aqueous solution of one or more pharmaceutically acceptable surface active agents selected from the group consisting of sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene fatty acid esters, polyoxyethylene castor oil derivatives, glyceryl fatty acid esters, sucrose fatty acid esters, alkly sulfates, dialkylsulfosuccinates and fatty acid sarcosinates and reheating the resulting dispersion to a temperature of from 40* to 60*C to obtain alpha-type crystals of chloramphenicol palmitate having an average particle diameter of from 0.06 to 0.19 microns.

Claim 5

A pharmaceutical preparation in the form of an aqueous suspension prepared by the process which comprises melting 1 to 20 parts chloramphenicol palmitate alone at a temperature of from 90* to 95*C, mixing the melt with an aqueous solution containing from 0.05 to 10 parts of one or more pharmaceutically acceptable dispersing agents selected from the group consisting of polyvinyl alcohol, polyvinylpyrrolidone, hydroxypropylcellulose, sodium carboxymethylcellulose, hydroxypropyl methylcellulose, gum arabic, carboxyvinyl polymer, polyethylene glycols, propylene glycol, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene fatty acid esters, polyoxyethylene castor oil derivatives, glyceryl fatty acid esters, sucrose fatty acid esters, alkyl sulfates, dialkylsulfosuccinates and fatty acid sarcosinates and 70 to 99 parts water at a temperature of from 60*C to the melting point of the chloramphenicol palmitate, cooling the resulting dispersion to room temperature, and subjecting the resulting cooled dispersion to A. reheating to a temperature of from 40* to 60*C, or B. addition of an aqueous solution containing from 1 to 10 parts based on the total parts of aqueous solution of 1 or more pharmaceutically acceptable surface active agents selected from the group consisting of sorbitan fatty acid esters, polyoxyethylene fatty acid esters, polyoxyethylene castor oil derivatives, glyceryl fatty acid esters, sucrose fatty acid esters, alkyl sulfates, dialkylsulfosuccinates and fatty acid sarcosinates and reheating the resulting solution to a temperature of from 40* to 60*C to obtain alpha-type crystals of chloramphenicol palmitate having an average particle diameter of from 0.06 to 0.19 microns.

Claim 6

A pharmaceutical preparation in the form of an aqueous suspension prepared by the process which comprises melting 1 to 20 parts chloramphenicol palmitate alone at a temperature of from 90* to 95*C, mixing the melt with an aqueous solution containing from 0.05 to 10 parts of one or more pharmaceutically acceptable dispersing agents selected from the group consisting of polyvinyl alcohol, polyvinylpyrrolidone, hydroxypropylcellulose, sodium carboxymethylcellulose, hydroxypropyl methylcellulose, gum arabic, carboxyvinyl polymer, polyethylene glycols, propylene glycol, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene fatty acid esters, polyoxyethylene castor oil derivatives, glyceryl fatty acid esters, sucrose fatty acid esters, alkyl sulfates, dialkylsulfosuccinates and fatty acid sarcosinates and 70 to 99 parts water at a temperature of from 60*C to the melting point of the chloramphenicol palmitate, cooling the resulting dispersion to room temperature, and subjecting the resulting cooled dispersion to A. reheating to a temperature of from 40* to 60*C, or B. addition of an aqueous solution containing from 1 to 10 parts based on the total parts of aqueous solution of 1 or more pharmaceutically acceptable surface active agents selected from the group consisting of sorbitan fatty acid esters, polyoxyethylene fatty acid esters, polyoxyethylene castor oil derivatives, glyceryl fatty acid esters, sucrose fatty acid esters, alkyl sulfates, dialkylsulfosuccinates and fatty acid sarcosinates and reheating the resulting solution to a temperature of from 40* to 60*C to obtain alpha-type crystals of chloramphenicol palmitate having an average particle diameter of from 0.06 to 0.19 microns.