ABSTRACT
OBJECTIVE: To establish a mini-column centrifugation method to determine the encapsulation efficiency (EE) of novel solid lipid nanoparticles containing oleic acid-CAT3 conjugates (OA-CAT3-SLN) and normal CAT3 SLN (CAT3-SLN). METHODS: Sephadex G-50 mini-columns were used to separate the encapsulated drug and free drug in the solid lipid nanoparticles (SLN) with the help of centrifugation. The boundary point of the elution between the encapsulated drug and free drug was established by the elution curve. The encapsulated drug in the SLN was eluted with 1 mL water for three times. Then 2 mL of ethanol was used to elute the separated free drug for three times. The eluted CAT3 was quantified by the verified HPLC-UV method and used to calculate the EE. The method was verified with the recovery and repeatability test. Finally, the EE of three batches of OA-CAT3-SLN and CAT3-SLN were determined. RESULTS: The mini-column centrifugation method could effectively separate the free drug from the encapsulated drug in SLN. The column recovery was (99.64±1.97)% (n=9), and the result of EE repeatability test of OA-CAT3-SLN was (83.71±0.70)% (n=5). The EE of OA-CAT3-SLN and CAT3-SLN were (86.26±2.65)% and (72.22±4.52)%, respectively (n=3). CONCLUSION: The established separation method is simple and reliable, with high recovery and good repeatability, and can distinguish different preparation processes.
ABSTRACT
Objective: To prepare and characterize gambogenic acid loaded nanostuctured lipid carrier (GNA-NLC). Methods: GNA-NLC was prepared by emulsion evaporation-low temperature solidification method, and its optimal prescription was selected by orthogonal test design. The characteristics, such as encapsulation efficiency (EE), average diameter, and Zeta potential, were studied. Results: GNA-NLC had a spherical shape with smooth surface with the average diameter of (144.07 ± 1.44) nm, polydispersity index (PI) of 0.24 ± 0.01, Zeta potential of (-28.03 ± 0.29) mV. The EE and drug loading were (84.65 ± 0.98)% and (4.21 ± 0.05)%, respectively. DSC indicated that GNA was dispersed as non-crystalline in matrix. Conclusion: Emulsion evaporation-low temperature solidification method is easy, simple, and feasible to prepare GNA-NLC.