Formulation of dried lignans nanosuspension with high redispersibility to enhance stability, dissolution, and oral bioavailability / 中国天然药物

Herpetospermum caudigerum lignans (HTL), one of the potential drugs with anti-hepatitis B virus and hepatoprotective effects, has limited clinical applications because of poor aqueous solubility and low bioavailability. Both herpetrione (HPE) and herpetin (HPN) are the most abundant ingredients in HTL and exhibit weak acidity. The purpose of the present study was to produce dried preparations of HTL (composed of HPE and HPN) nanosuspensions (HTL-NS) with high redispersibility using lyophilization technology. The HTL-NS was prepared by utilizing precipitation-combined homogenization technology based on acid-base neutralization reactions, and critical formulation and process parameters affecting the characteristics of HTL-NS were optimized. The resultant products were characterized by particle size analysis, SEM, XRD, stability, solubility, dissolution and in vivo bioavailability. HTL-NS showed near-spherical-shaped morphology and the size was 243 nm with a narrow PDI value of 0.187. The dried preparations with a relatively large particle size of 286 nm and a PDI of 0.215 were achieved by using 4% (W/V) mannitol as cryoprotectants, and had a better stability at 4 or 25 °C for 2 months, compared to HTL-NS. In the in vitro test, the dried preparations showed markedly increased solubility and dissolution velocity. Besides, in the in vivo evaluation, it exhibited significant increases in AUC, CMRT and a decrease in T, compared to the raw drug. In conclusion, our results provide a basis for the development of a drug delivery system for poorly water-soluble ingredients with pH-dependent solubility.

Preparation of tanshinone ⅡA loaded nanostructured lipid carrier and its in vitro transdermal permeation characteristics / 中国中药杂志

To prepare tanshinone ⅡA loaded nanostructured lipid carrier (Tan ⅡA-NLC), and study its in vitro transdermal permeation characteristics. The Tan ⅡA-NLC was prepared by high pressure homogenization technology and optimized by Box-Behnken design-response surface method, and it was characterized in terms of morphology, particle size, zeta potention, et al. The transdermal permeation of Tan ⅡA-NLC was evaluated by using Franz diffusion cells. The results showed that, the optimal formulation was as follows: drug/lipid materials ratio 88, GMS/MCT ratio 2, emulsifier concentration 1%, average particle size (182±14) nm, polydispersity index PDI (0.190 6±0.024 5), zeta potential (－27.8± 5.4) mV, encapsulation efficiency EE (86.44%±9.26%) and drug loading DL (0.98%±0.18%), respectively. The in vitro transdermal permeation results showed that as compared with Tan ⅡA solution, Tan ⅡA-NLC had lower transdermal permeation amount after applying drug for 24 h, but its retention in the epidermis was 3.18 times that of solution. These results indicated that the prepared Tan ⅡA-NLC could effectively increase the regention of Tan ⅡA in the epidermis, and had a broad application prospect.