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Objective:To study the in vitro and in vivo transdermal penetration of testosterone undecanoate ( TU) binary ethosomes gel. Methods:TU binary ethosomes were prepared by an ethanol injection method, and using carbopol 941 as the gel base, TU binary ethosomes gel was prepared. Using mouse skin as the barrier, Franz cells were applied to explore the in vitro transdermal penetration of TU binary ethosomes and the gel. Rats were used as the animals, and TU binary ethosomes and the gel was respectively administrated on the back skin. At the predetermined time points, plasma samples were withdrawn to detect the concentration of TU, and the main pharmacokinetics parameters were calculated. Results: The in vitro transdermal penetration of TU binary ethosomes and the gel was both fitted first-order equation:Q=8. 68t+6. 78(r=0. 998 2) and Q=6. 09t+3. 09(r=0. 999 3), and the stable penetration rate was 8. 68 μg·cm-2 ·h-1 and 6. 09μg·cm-2 ·h-1 , respectively. After the 24-hour penetration, the residual amount in skin of TU binary ethosomes and the gel was (208. 80 ± 55. 26)μg·g-1 and (225. 60 ± 38. 90)μg·g-1 , respectively. The main pharmacokinet-ics parameters of TU binary ethosomes and the gel were Cmax of(18.50 ±2.75)mg·L-1 and(20.80 ±2.42)mg·L-1, tmax of(6.20 ± 0. 14)h and(9. 54 ± 0. 52)h, and AUC0-48h of(336. 74 ± 2. 05)h and(486. 30 ± 1. 68)h. Conclusion:TU binary ethosomes and the gel both exhibit promising in vitro transdermal penetration, and the gel shows better sustained release property.
RESUMO
To screen the optimal formula and evaluate the quality of testosterone undecanoate ( TU) binary ethosomes to lay the foundation for the transdermal delivery system of TU. Methods:The mixture of ethanol and propylene glycol was used as the softeners, and TU binary ethosomes were prepared by ethanol injection method. The ratio of TU to lipids ( A) , the quality percentage of the mixture of ethanol and propylene glycol ( B) and the ratio of ethanol to propylene glycol ( C) as the influencing factors, and the entrapment efficiency as the index, an orthogonal test was used to optimize the formula of TU binary ethosomes. The morphology, size, zeta potential, in vitro drug release and stability of TU binary ethosomes were studied. Results:The optimal formula of TU binary etho-somes were as follows:the ratio of TU to lipids was 1∶15, the quality percentage of the mixture of ethanol and propylene glycol was 10% and the ratio of propylene glycol to ethanol was 6∶4. The optimal TU binary ethosomes were concentric circles under an optical microscope with uniform size, and the average size was (185. 5 ± 52. 8)nm, zeta potential was ( -15. 87 ± 0. 26)mV, and the entrap-ment efficiency was (79. 14 ± 0. 66)%. TU release from the binary ethosomes in vitro was fitted the first-order equation:Q=20. 79t-11. 01 (r2 =0. 998 4). Under the high temperature, the entrapment efficiency was decreased significantly, while under the other test conditions, all the indices of TU binary ethosomes showed no significant difference. Conclusion:The optimal TU binary ethosomes are easy to be prepared with promising quality and sustained release property in vitro, which are valuable to be studied further.
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Objective:To establish a method to determine the entrapment efficiency of loratadine binary ethosomes. Methods:The gel microcolumn centrifugation method was employed to separate the free drug from loratadine binary ethosomes. The content of lorata-dine was determined by HPLC to calculate the entrapment efficiency. Results: A calibration linear curve of loratadine concentration was within the range of 10. 2-102. 0 μg·ml-1(r=0. 999 5). The average entrapment efficiencies of three batches of loratadine binary ethosomes were 86. 75%, 87. 26% and 86. 00%, respectively. Conclusion:The method is simple and rapid, and can be used to de-termine the entrapment efficiency of loratadine binary ethosomes accurately.