REVIEW ARTICLE- SPHERICAL CRYSTALLIZATION– A NOVEL DRUG DELIVERY SYSTEM

Abstract

Spherical crystallization is the novel agglomerated technique that can directly transform the fine crystals produced in the crystallization process into a spherical shape. It is the particle engineering technique by which crystallization and agglomeration can be carried out simultaneously in one step to transform crystals directly into compacted spherical form. Spherical crystallization of drugs is the process of obtaining larger particles by agglomeration during crystallization. The most common techniques used to obtain such particles are spherical agglomeration and quasi-emulsion solvent diffusion. Ammonia diffusion systems and crystalloid- co-agglomeration are extensions of these techniques. 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. To improve the dissolution rate of poorly soluble drugs, fine crystals are referred and this micronisation can change drug powder properties such as wet ability, compressibility, packability and flow. General methods of spherical crystallization are spherical agglomeration, emulsion, solvent diffusion method, ammonia diffusion method, neutralization method. The principle steps involved in the process 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.