Spherical crystallization –A novel drug delivery system

Abstract

Today, the tablet is the most popular dosage form, covering around 50% of total oral drug delivery system and accounting 75% of all pharmaceutical preparation produced .It promotes statbility, portability and acceptable patient compliance .The quality of solid dosage form is primarily influenced by micromeritic characteristics such as the shape and size of drug crystal, especially in the case of poorly soluble drugs. To improve the dissolution rate of poorly soluble drugs, fine crystals are referred and this micronisation can change drug powder properties such as wettability, compressibility, packability and flow. Further, it is more beneficial to convert micro crystalline drugs into an agglomerated form using spherical crystallization technique. The resulting spherically agglomerated crystals can be directly prepared into a tablet, thus direct tabletting saves time and reduces cost .General methods of spherical crystallization are spherical agglomeration, emulsion, solvent diffusion method, ammonia diffusion method, neutralization method .The principle steps involved in the process of sc are flocculation zone, zero growth zone, fast growth zone, constant size zone .There is a wide application of spherical crystallization:-improvement of flow ability, compressibility of poorly compressible drug, masking bitter taste of drug, improving solubility and dissolution rate of poorly soluble drug and thus improve bioavailability of drug.