Process for cleaning hard gelatine capsules

A process for cleaning the inner wall of a hard gelatine capsule for use in inhalation therapy to at least remove lubricant or mould release agent thereon, wherein the process comprises:

• (a) screening one or more ingredients in a powder formulation with a screen;
• (b) mixing the ingredient or ingredients from step (a) in a mixer;
• (c) transferring the powder formulation obtained from step (b) into a gelatine capsule, wherein the powder formulation content in the gelatine capsule is from 6% (v/v) to 50% (v/v) of maximum capacity of the gelatine capsule;
• (d) placing multiple capsules from step (c) into a mixing container, and agitating the mixing container for about 20 minutes to 150 minutes, resulting in cleaning of the capsule walls at least by removing lubricant or mould release agent thereon;
• (e) visually monitoring the cleaning to a selected endpoint comprises opening the capsule to determine the point at which powder no longer can be observed on the capsule inner wall;
• (f) emptying and refilling the gelatine capsule with an active substance formulation;
• and
• wherein steps (a) through (f) are performed at a temperature of between about 15° C. and 50° C. and a relative humidity of between about 35% and 65%, and the cleaning step (d) is carried out without the use of solvents.