| Ganoderic acid T (GA-T), one kind of triterpenoids, is isolated from Ganoderma lucidum. Domestic and international research showed that GA-T could inhibit tumor cell invasion and metastasis in vitro and in vivo, induce apoptosis of cancer cells, increase natural killer cell activity, improve immune level and so on. In this paper, we studied on preparation of GA-T tablet and its pharmacokinetics.A selective and sensitive HPLC method has been developed and validated for the quantification of GA-T in rat plasma. A reverse-phase column was used with UV detection at 245 nm. The mobile phase consisted of methanol-water-acetic acid (95.5:4.5:0.05, v/v/v) run at a flow rate of 1 mL/min. Testosterone propionate was used as the internal standard. The standard curve was linear over the range of 0.05-50μg/mL in rat plasma with a linear correlation coefficient greater than 0.999. The lower limit of quantification of this assay was 20 ng/mL. The recoveries of samples at 0.05,2 and 40μg/mL were 97.6%,98.4% and 103.2%, respectively. The relative standard deviations of intra-and inter-day assay variations were less than 8.2%. The usefulness of the assay was confirmed by the successful analysis of plasma samples from a pharmacokinetics study in rats. Following a single dose of ganoderic acid T (5 mg/kg for i.v. or 14 mg/kg for p.o.), the main pharmacokinetic parameters by intravenous injection were:1/2α:(5.46±1.25) min; t1/2β:(227.18±11.40) min; CL:(1.09±0.16) mL/kg/min; AUC0-12h:(3939.13±311.14)μg-min/mL; AUC0-∞:(4681.96±710.70)μg-min/mL and the absolute bioavailability was (41.98±2.40)%. This method is simple, sensitive and accurate. It is suitable for pharmacokinetic studies of ganoderic acids in rats.GA-T tablets were prepared by direct powder compression. The excipients were selected on the basis of flowability and compressibility of the powder. The appearance, hardness, disintegration time and tablet weight variations were investigated. The type and amount of excipients were investigated by single-factor method. Microcrystalline cellulose and spray-dried lactose were selected as excipients. Silica powder was added as glidant and magnesium stearate as lubricant. The formulation of GA-T tablet was optimized. GA-T tablets were prepared by equivalently mixing GA-T powder, microcrystalline cellulose and spray-dried lactose. Silica powder and magnesium stearate were added before tabletting. GA-T tablet had a good appearance and qualified tablet weight variations. Its disaggregattion was quickly and dissolution was completely. The evaluation indexes were accorded with the 2010 version Chinese Pharmacopoeia. Results of influence factor experiments showed that GA-T tablet resist to high temperature and strong light. At high humidity condition (75%), GA-T showed significantly lower of dissolution rate, indicating that the preparation was moisture-sensitive. It was suggested that the GA-T tablet should be kept in dry place.An HPLC method was established for the determination of GA-T in rabbit plasma. Following a single dose of GA-T (1.5 mg/kg for i.v. or 7 mg/kg for p.o. or a tablet (20 mg) for p.o.), the concentration of drug in plasma was determined and plasma concentration-time curves were obtained. The main pharmacokinetic parameters were analyzed by pharmacokinetic software kinetica 4.41. The absolute bioavailability of GA-T after oral administration was (37.16±8.53)%. The absolute bioavailability of oral GA-T tablet was (33.03±9.82)%.
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