Research on stability of melittin in different solvent systems / 中国中药杂志

The stability of melittin in different solvents (water, deoxygenated water, physiological saline, PBS, 50% ethanol, ethanol, glycerol)was studied and the results showed that the stability of melittin is not influenced by light, temperature and pH in 50% ethanol, which melittin can be completed dissolved when compared with ethanol and glycerol, in such, 50% ethanol was chosen as solvent storage when measured content of melittin. Then the effect of different concentrations of PBS, the pH of PBS and rat skin ho- mogenates were tested, and the results showed that melittin was degraded rapidly at low concentration solution and low ionic strength. Increasing pH of PBS and rat skin homogenate can accelerate the degradation of melittin. These researches provide an experimental ba- sis for further study of melittin.

Selecting solvent and solubilizer for puerarin nasal drops by solubility and irritation / 中国中药杂志

In order to test the equilibrium solubility of puerarin in different solvents and solubilizer,cilia toxicity and irritation of these excipient, the balance method, toad in the ciliary body toxicity and rat nasal mucosa irritation were used respectively. Results showed that puerarin solubility was 56.44 g x L(-1) in combined solvent of 30% PEG200 and 10% Kolliphor HS 15. With normal saline solution as negative control and sodium deoxycholate as positive control, the effects of 30% PEG200, 30% PEG 400, 10% Kolliphor HS 15 and combination of 30% of PEG200 and 10% Kolliphor HS 15 on toad palate cilium were observed and cilia movement duration was recorded. The results indicated that there was no significant difference in cilia movement duration among 30% PEG200, 10% Kolliphor HS 15 and normal saline group. The rats long-term nasal mucous membrane irritation of 30% PEG 400, 10% Kolliphor HS 15, which had no cilia toxicity, was studied, with normal saline solution as negative control. There were no significant difference revealed on rat nasal mucosa epithelial thickness among 30% PEG 400, 10% Kolliphor HS 15 and normal saline. Above researches showed 30% PEG 400, 10% Kolliphor HS 15 was ideal for solubility of puerarin nasal drops and showed a lower cilia toxicity and irritation, and can be used as the solvent and solubilizer of puerarin nasal drops.

Studies on transdermal delivery of ferulic acid through rat skin treated by microneedle arrays / 中国中药杂志

In order to investigate the characteristics of transdermal delivery of ferulic acid under the treated of microneedle arrays and the influence on permeability of rat skin capillaries, improved Franz-cells were used in the transdermal delivery experiment with the rat skin of abdominal wall and the length of microneedle arrays, different insertion forces, retention time were studied in the influence of characteristics of transdermal delivery of FA. The amount of FA was determined by HPLC system. Intravenous injection Evans blue and FA was added after microneedle arrays treated. Established inflammation model was built by daubing dimethylbenzene. The amount of Evans blue in the rat skin was read at 590 nm wavelength with a Multiskan Go microplate reader. Compared with passive diffusion group the skin pretreated with microneedle arrays had a remarkable enhancement of FA transport (P <0.01). The accumulation of FA increased with the enhancement of insertion force as to as the increase of retention time. Microneedle arrays with different length had a remarkable enhancement of FA transport, but was not related to the increase of the length. The research of FA on the reduce of permeability of rat skin capillaries indicated that the skin pretreated with microneedle arrays could reduce the content of Evans blue in the skins of rat significantly compared with the untreated group. The permeation rate of ferulic acid transdermal delivery had remarkable increase under the treated of microneedle arrays and the length of microneedle arrays ,the retention time so as to the insertion force were important to the transdermal delivery of ferulic acid.

Study on drug release performance of compound Nanxing pain pastes with different stromata / 中国中药杂志

Solvent and emulsion pressure-sensitive patches for compound Nanxing pain paste were prepared respectively in this study. Franz diffusion cell method was adopted to determine in vitro release of eugenol in compound Nanxing pain paste of the two stromata, with microfiltration membranes in place of skins. The results of the experiment demonstrated that solvent pressure-sensitive patches were superior to emulsion pressure-sensitive patches in terms of the accumulated release percentage of eugenol, with both of their release processes in line with Higuchi model and non-Fick diffusion mechanism. In conclusion, emulsion pressure-sensitive stroma was more beneficial to in vitro release of eugenol in compound Nanxing pain paste.