GB1149648A - Sterilisation of solids for use in aqueous suspensions - Google Patents

Abstract

1,149,648. Sterilising particulate materials. MERCK & CO. Inc. 5 Sept., 1966 [7 Sept., 1965], No. 39536/66. Headings A5B and ASG. particulate water-insoluble solid medicinal materials are sterilised by suspending them in an aqueous saturated solution of sodium chloride containing excess undissolved sodium chloride, heating the suspension to a temperature above 100‹C, and maintaining this temperature until sterilisation is effected, the excess of sodium chloride being sufficient to maintain saturation at the said temperature. Heating is preferably at 110‹ to 130‹C at elevated pressure, (e.g. by autoclaving); the sodium chloride may be present in 10% excess of the amount needed to form a saturated solution at 100‹C. The process is especially directed to sterilising steroids, such as dexamethasone or its phosphate, acetate or tertiary butyl-acetate, hydrocortisone, methyl prednisolone acetate, betamethasone acetate, and triamcinolone acetonide, but may also be used for any non- electrolyte salts or salt formers, e.g. indomethacin and thiobendazole. The aqueous suspension preferably includes a surface active agent, e.g. polyoxyethylene sorbitan monolaurate. Sterile compositions for parenteral use or opthalmic application are prepared, which contain in addition to one or more of the aforesaid ingredients, one or more suspending agents, e.g. sodium carboxymethyl cellulose, hydroxyethyl cellulose or sorbitol; chelating agents, e.g. N, - ethylene - diamine - tetra - acetate; preservatives, e.g. Na. - bisulphite or benzalkonium chloride; lecithin; creatinine; phenethyl alcohol; benzyl alcohol; and lidocaine. The process is useful for sterilizing drugs of pre-determined particle size, and is said not to cause alteration of the particle size.