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A rapid, sensitive, and simple gas chromatographic method with flame ionization detection is developed for the simultaneous determination of tetramethylpyrazine phosphate (TMPP) and borneol in mouse plasma and brain tissue. Sample preparations are carried out by deproteinization with an internal standard solution in methanol. The analytes and internal standard (dimethyl sulfoxide) are well-separated on an HP-5 MS capillary column. The analytical curves are linear over a wide concentration range of 0.02-40 microg/mL for both TMPP and borneol in plasma and brain tissue, with the intra- and inter-day precision (the relative standard deviation values) at less than 15%. TMPP and borneol are both stable under different conditions. The method described is successfully applied to the pharmacokinetic study of mouse plasma and brain tissue after oral administration of the Fufang TMPP and TMPP tablets to mice.

The main purpose of this study was to illustrate the effect of synthetical borneol (SB) on the plasma and brain concentration profile of tetramethylpyrazine phosphate (TMPP) in mice after oral administration of TMPP without or with different amounts of SB. The concentrations of TMPP on the plasma and brain in mice were determined by GC-FID. The pharmacokinetic parameters were computed by software program 3p97. Our data showed that after oral administration of 15, 30, 90 mg kg(-1) of SB, oral bioavailability of TMPP in plasma was 1.52, 2.21, 2.95 times increase, respectively, than that without SB, and 1.12, 1.62, 1.93 times increase, respectively, in brain tissue. The pharmacokinetic data were simulated by non-linear least squares. The results showed that both open two-compartment model and one-order absorption were fitted to TMPP plasma and brain concentration-time course in vivo in mice. The MRT of TMPP showed same results under the conditions without or with SB. SB did enhance the oral absorption of TMPP and the concentration of TMPP in brain tissue, especially in the early period. But the use of SB did not change the behavior in vivo of TMPP.

The aim of the present study was to find a method to increase oral bioavailability of silymarin, that is to say, by the preparation of silymarin proliposome and to compare the pharmacokinetic characteristics and bioavailability after oral administration of silymarin proliposome and silymarin in beagle dogs. Silymarin proliposome was prepared by the film-deposition on carriers. After the proliposome was contacted with water, the silymarin liposome suspensions formed automatically. The tests of physicochemical properties including SEM, TEM, encapsulation efficiency, dissolution studies, particle size of the reconstituted liposome and stability of the silymarin proliposome were determined by laser-particle-sizer, HPLC, etc. The concentrations of silymarin in plasma of beagle dogs and its pharmacokinetic behaviors after oral administration of silymarin liposome suspensions and silymarin were studied by RP-HPLC. The pharmacokinetic parameters were computed by software program 3p97. The encapsulation efficiency of silymarin liposome could be more than 90%, with an average particle size of about 196.4 nm and the proliposome appeared a very stability at 40 degrees C during 3 months. It was found that mean plasma concentration-time curves of silymarin after oral administration of liposome suspensions and silymarin in beagle dogs were both in accordance with open two-compartments model and first-order absorption. Pharmacokinetic parameters of silymarin proliposome and silymarin in beagle dogs were Tmax both 30 min; Cmax 472.62 and 89.78 ng mL(-1); and AUC0-infinity 2606.21 and 697 ng mL(-1)h, respectively. The high bioavailability of silymarin proliposome could be obtained by oral administration. Silymarin proliposome was stable and did enchance the gastrointestinal absorption of silymarin.