Encapsulation Techniques and Controlled Release

Abstract

Encapsulation is the protection of at least one active ingredient by at least one kind of coating material, provided that it is released under appropriate conditions and at the desired dose. The used material must be biocompatible and biodegradable, as well as ensuring the stability of the active ingredient. Controlled release systems have numerous advantages; such as, enhanced efficacy, high stability against enzymatic etc. degradation of encapsulated or immobilized components, reduced toxicity, and easy application. The release systems can be in different forms such as sphere, capsule, rod, membrane, slab, etc. Its dimensions, on the other hand, can be of different sizes due to the purpose of use; it can vary between nano, micro or milli levels. These forms, which are generally called micro- and nanoparticles; can be carriers of active ingredients such as drugs, vitamins, minerals, volatile aromatic compounds and various nutritional supplements called nutraceuticals. The main goal in encapsulation is the preservation of sensitive components and their release over time to a set extent. There are different techniques commonly used for the encapsulation of active substances into micro or nanoparticles. These are the techniques; thermal phase separation (coacervation), spray cooling and freezing, melt dispersion, solvent evaporation, fluidized bed coating, spray drying, homogenization of water and organic phases, rotary suspension separation, extrusion and inclusion complex, etc. The aim of this review is to give general information about the controlled release of active ingredients with different encapsulation techniques.

Keywords

• Controlled release
• Encapsulation
• Active substance

Enkapsülasyon Teknikleri ve Kontrollü Salım

Öz

Enkapsülasyon, en az bir aktif bileşenin en az bir çeşit kaplama materyali tarafından uygun koşullarda ve istenilen dozda salınması koşuluyla koruma altına alınmasıdır. Kullanılacak malzemenin biyouyumlu ve biyobozunur olması yanı sıra aktif bileşenin stabilitesini sağlıyor olması da gereklidir. Kontrollü salım sistemleri; gelişmiş etkinlik, enkapsüle veya immobilize edilmiş bileşenlerin enzimatik vb. degradasyonuna karşı yüksek stabiliteye sahip olması, azaltılmış toksisite, kolay uygulama gibi sayısız avantajlara sahiptirler. Salım sistemlerinin formu küre, kapsül, çubuk, membran, slab gibi farklı biçimlerde olabilmektedir. Boyutları ise kullanım amacı sebebiyle farklı ölçülerde olabilmekte; nano, mikro veya mili seviyeler arasında değişebilmektedir. Genel olarak mikro- ve nanoparçacıklar olarak isimlendirilen bu formlar; ilaçlar, vitaminler, mineraller, uçucu aromatik bileşikler ve nutrasötik olarak adlandırılan çeşitli besin takviyeleri gibi aktif bileşenlerin taşıyıcısı olabilmektedirler. Enkapsülasyonda asıl hedef hassas bileşenlerin korunması ve zamanla ayarlanan ölçüde salınmasıdır. Mikro veya nanopartiküller içindeki aktif maddelerin enkapsülasyonu için yaygın olarak kullanılan farklı teknikler mevcuttur. Bunlar; termal faz ayırma (koaservasyon), sprey soğutma ve dondurma, eriyik dağılımı, çözücü buharlaşması, akışkan yatak kaplaması, sprey kurutma, su ve organik fazların homojenizasyonu, dönel süspansiyon ayırma, ekstrüzyon ve inklüzyon kompleksi vb. tekniklerdir. Bu derlemenin amacı farklı enkapsülasyon teknikleri ile aktif bileşenlerin kontrollü salımı hakkında genel bilgiler vermektir.

Anahtar Kelimeler

• Kontrollü salım
• Enkapsülasyon
• Aktif bileşen

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