ABSTRACT
OBJECTIVE To prepare Xiongzhi shigao decoction soluble microneedles， characterize it and investigate its transdermal properties in vitro. METHODS Two-step centrifugal method was used to prepare Xiongzhi shigao decoction soluble microneedles. The formability and mechanical property of the microneedles were evaluated from aspects of stroma fluidity， microneedle formability， needle hardness， etc. The appearance， mechanical strength， dissolution performance， skin barrier recovery performance and drug loading of the prepared microneedles were characterized by using active components of the soluble microneedle （chlorogenic acid， ferulic acid， notopterol， imperatorin， ligustilide， isoimperatorin） as indicators. The in vitro transdermal performance was investigated by Franz diffusion cell. RESULTS The soluble microneedle tips of Xiongzhi shigao decoction prepared in this study were conical， evenly distributed and of the same thickness， with good mechanical properties； the tip of the needle could be almost completely dissolved after being penetrated into the skin of rats for 2 hours， and the skin barrier recovery performance was good； the drug loading of chlorogenic acid， ferulic acid， notopterol， imperatorin， ligustilide and isoimperatorin were （87.04±1.12）， （67.69±1.23）， （20.65±0.17）， （35.00±0.11）， （153.83±0.21） and （23.52±0.50） μg per patch respectively. The results of in vitro transdermal study showed that cumulative release rates of 6 active components in this microneedle after 72 hours were 36.94%， 56.72%， 19.36%， 57.98%， 11.06% and 35.19%， respectively. CONCLUSIONS Xiongzhi shigao decoction soluble microneedles are prepared successfully in this study and have good formability， mechanical properties and pliable backing， which can significantly promote the transdermal drug delivery.
ABSTRACT
Triptolide(TP), the main active and toxic component of Tripterygium wilfordii, has the limitations of low bioavailability, poor absorption, low concentration in plasma, and small lethal dose. Microneedle(MN), the hybrid of hypodermic needle and transdermal patch, is a physical penetration-enhancing system. Dissolving microneedles(DMNs) can be tailored to specific needs of degradation rate. In this study, the TP-loaded DMNs(DMNs-TP) were prepared with the two-step centrifugation method. The optimal ratio of PVA to PVP K30, water content in matrix solution, demoulding method, and plasticizer for preparing DMNs were investigated with the indexes of formability and mechanical strength. The drug loading capacity was determined by HPLC and morphological characteristics were observed under an optical microscope. The mechanical properties were investigated by H&E staining and Franz diffusion cell was used to detect the in vitro skin permeation characteristics. Through the experiment, we confirmed that the optimal backing material should be PVA and PVP K30(3∶1) and the optimal ratio of matrix material to water should be 3∶4. The prepared DMNs-TP were pyramidal with smooth surface and length of approximately 550 μm. Each patch(2.75 cm~2) had the drug loading capacity of(153.41±2.29) μg, and TP was located in the upper part of the needle. The results of in vitro skin permeation assay demonstrated that the cumulative penetration of TP in DMNs-TP reached 80% in 24 h, while little TP solution penetrated the skin, which proved that DMNs promoted the transdermal delivery of TP.
Subject(s)
Administration, Cutaneous , Diterpenes , Drug Delivery Systems , Epoxy Compounds , Needles , Phenanthrenes , SkinABSTRACT
Objective: To investigate the changes of matrine concentration in rat local skin with time after transdermal administration of matrine transfersomes, and to evaluate the transdermal delivery properties. Methods: The matrine transfersomes were applied non-occlusively onto rat skin in vivo with abdominal hair removal, and the concentration of drugs in microdialysate of skin was detected by microdialysis and reverse phase high performance liquid chromatography. Furthermore, the concentration-time curves of matrine in microdialysates of skin were compared among marine transfersomes, liposomes, and deoxysodium cholate solution. Results: After the transfersomes were given to rats, the maximum peak time (tmax) of matrine skin concentration appeared at (4.200 ± 0.447) h. The maximum skin concentration (Cmax) was (0.927 ± 0.251) μg/mL and area under the curve (AUC0-8) was (5.033 ± 1.526) μg·h·mL-1, which were much higher than those of the liposomes and the solution (containing 0.8% sodium deoxycholate, P < 0.05), while tmax shortened much more than that of them. Conclusion: In vivo skin microdialysis could be used to assess the transdermal delivery properties of matrine transfersomes. And matrine transfersomes have the good transdermal permeability and efficacy.