Disclosed are improved granular pharmaceutical preparations, together with improved methods and apparatus for preparation of granules for use in such preparations. Such methods are especially useful for making granules for solid oral dose pharmaceutical preparations, and are particularly suited to the production of granules comprising 5-aminosalicylic acid (5-ASA) for the treatment of inflammatory bowel disease. The granules exhibit a more sharply peaked length distribution, and hence aspect ratio distribution, and have a consequently much sharper dissolution profile after further processing.