Preparation and characteristics of hydroxypropyl-β-cyclodextrin polymeric nanocapsules loading nimodipine

Preparation and characteristics of hydroxypropyl-β-cyclodextrin polymeric nanocapsules loading nimodipine

http://www.ebiochem.com/product/hydroxypropyl-beta-cyclodextrin-98-4518

Cyclodextrins, as they are known today, were called "cellulosine" when first described by A. Villiers in 1891. Soon after, F. Schardinger identified the three naturally occurring cyclodextrins -α, -β, and -γ. These compounds were therefore referred to as "Schardinger sugars". For 25 years, between 1911 and 1935, Pringsheim in Germany was the leading researcher in this area, demonstrating that cyclodextrins formed stable aqueous complexes with many other chemicals. By the mid 1970s, each of the natural cyclodextrins had been structurally and chemically characterized and many more complexes had been studied. Since the 1970s, extensive work has been conducted by Szejtli and others exploring encapsulation by cyclodextrins and their derivatives for industrial and pharmacologic applications. Among the processes used for complexation, the kneading process seems to be one of the best.

Nimodipine loaded hydroxypropyl-β-cyclodextrin polymeric nanocapsules were prepared by interfacial polyaddition of hydroxypropyl-β-cyclodextrin and isophorone diisocyante in a miniemulsion system(By Zhejiang University).The effects of ultrasonicate times on the preparation of miniemulsion, the total amount of hydroxypropyl-β-cyclodextrin and isophorone diisocyante, and the molar ratio of isophorone diisocyante to hydroxypropyl-β-cyclodextrin on the capsule size and drug release behavior from capsule were investigated. The chitosan based polymeric nanocapsules were prepared as a control to study the effect of hydroxypropyl-β-cyclodextrin molecules in capsule matrix on the drug release. The results indicated that the droplet size of miniemulsion and capsule size decreased with increasing sonicate times. When the total amount of hydroxypropyl-β-cyclodextrin and isophorone diisocyante, and the molar ratio of isophorone diisocyante to hydroxypropyl-β-cyclodextrin were increased, the capsule as well, but the drug release rates from capsules became slower. The drug release behaviors from hydroxypropyl-β-cyclodextrin polymeric nanocapsules were affected by the drug diffusion through the polymer matrix and the formation of inclusion complex between drug and hydroxypropyl-β-cyclodextrin.

The hydroxypropyl-β-cyclodextrin-based polymeric capsules loading nimodipine with nanosized dimension could be prepared by interfacial polyaddition reaction in a miniemulsion system. The capsule size could be controlled by the sonicate treatment times in the preparation of miniemulsion. The total amount of hydroxypropyl-β-cyclodextrin and isophorone diisocyante, and the molar ratio of isophorone diisocyante to hydroxypropyl-β-cyclodextrin also affected the size of resulted capsule and the drug release behavior in vitro from the nanocapsules. The drug release behaviors in vitro from hydroxypropyl-β-cyclodextrin based polymeric capsules were influenced by the drug diffusion from polymeric matrix and the inclusion of drug and hydroxypropyl-β-cyclodextrin.