The Study Of Biopharmaceutics Classification System And Plasma Protein Binding Of Alliin

Objective: To study on the intrinsic dissolution rate, lipid-water partition coefficient and intestinal absorption of alliin for determining solubility and permeability, according to biopharmaceutics classification system research contents. To determine the bind rate for studying on the binding of plasma protein and alliin. Methods: 1. The apparatus for intrinsic dissolution test recorded in United States Pharmacopeia(USP) integrating with fiber-optic drug dissolution test system(FODT) were used to real-time monitor intrinsic dissolution processes of alliin in four media which were water, solution of HCl with pH1.2,buffer solution of acetate with pH4.5, and buffer solution of phosphate with pH6.8. The intrinsic dissolution rates(IDR) were calculated. 2. The partition coefficients for the n-octanol-water systems of alliin were determined by shaking flask method. 3. Ussing Chamber model was used to study on the permeabilities of alliin across the duodenum,jejunal, ileal and colonic membrances in rats. 4. Ultrafiltration was employed to determinate plasma protein binding rate of alliin. Results: 1. The IDR values of alliin with rotating disk system were 5.88, 8.35, 7.04 and 7.88 mg·cm-2·min-1 in four media,respectively. And the IDR values of alliin with stationary disk system were 10.88, 12.88,14.42 and 16.34 mg·cm-2·min-1, respectively. The similarity factors were 56.42, 50.75,40.30 and 40.64, respectively. 2. The lipid-water partition coefficient of alliin measured by the shaking flask method was-0.86±0.01. 3. The apparent permeability coefficients of alliin in aforesaid four intestinal segments were more than 1×10-6cm·s-1, and were not affected by the alliin concentration. The Ka increased along with the raised dosage. 4. The plasma protein binding rates of alliin were(54.85±5.95)%,(54.06±9.53)% and(45.01±3.95)% in human,(62.04±1.92)%,(55.05±2.77)% and(47.55±1.18)% in rat and(65.76±1.46)%,(64.99±2.99)% and(51.08±0.89)% in dog at 37℃, respectively.Conlusion: 1. The results showed that the intrinsic alliin dissolution rates were much greater than 1 mg·cm-2·min-1. It was infered that alliin dissolution would not be the rate limiting step to absorption. 2. Alliin dissolves in water easily, and the lipophilic propertywas poor. 3. Alliin is absorbed moderately by entire intestine of rat. The main absorption sites were in the ileum and jejunum. Absorption mechanism was probably facilitated diffusion. 4. Alliin is bonded with protein moderately at 37℃. There are significant differences between several species of plasma protein binding rates of alliin(P < 0.05).The largest plasma protein binding rate of alliin was of dog plasma.