LAYERING AND MICROENCAPSULATION OF THERMAL SENSITIVE BIOLOGICALLY ACTIVE MATERIAL USING HEAT ABSORBING MATERIAL LAYERS HAVING INCREASING MELTING POINTS
A layered microencapsulation structure and a method of preparation of the layered structure are provided herein. The layered microcapsules comprises different coating layers having a specific arrangement order where each layer is composed of at least one phase change material which is able to absorb heat from surroundings and still to keep constant temperature or an insignificant increase in temperature via a fusion process occurring at a specific temperature (e.g. melting point) and a core substrate that has a heat-sensitive component which is entrapped therein. The layered microencapsulation structure is designed in such a way that the layers are arranged with increasing order of the melting point from inside to outside. The method of microencapsulation comprises the step of dry cold granulation of a sensitive active material using a melt material resulting in a core substrate and layering using heat absorbing materials having increasing melting points. The core substrate is coated by different layers of phase change material having different melting points resulting in a layered microcapsule structure. After layering process the layered microcapsule may be optionally coated by an outermost layer which is soluble in GI tract.Linvention concerne une structure de microencapsulation stratifiée et une méthode de préparation de la structure stratifiée. Les microcapsules stratifiées comprennent différentes couches de revêtement arrangées dans un ordre donné, chaque couche étant composée dau moins un matériau à changement de phase qui est capable dabsorber la chaleur de son environnement tout en maintenant une température constante ou en subissant une augmentation de température négligeable grâce à un processus de fusion se produisant à une température spécifique (le point de fusion par exemple) et un substrat central qui comporte un composant sensible à la chaleur piégé à lintérieur. La structure de microencapsulation stratifiée est conçue de façon que les couches soien
