Category: Formulation and Quality
Purpose: We have developed a stability enhanced nano shell(SENS) delivery system composed of an amphiphilic block copolymer, anionic polymer, cationic lipid, helper lipid and anionic siRNA. According to guidance for industry for liposome drug products(April 2018, CDER(FDA)), drug product specification should include liposome contained and free drug substance (or encapsulation efficiency). So, we developed free siRNA quantitative analysis method using size exclusion chromatography(SEC).
Methods: The chromatographic analysis for SEC was performed on Shodex OHpak SB-804HQ (8.0x300 mm, 10 μm) using phosphate buffered saline solution (mobile phase) with a flow rate of 0.75 mL/min at column temperature 25℃ and detection was performed at UV 260nm. Due to size difference, free siRNA can be separated from the siRNA encapsulated SENS formulation at this analytical condition.
Results: Total siRNA amount was measured by IP-RP(Ion pairing-reverse phase chromatography) analysis. Thus free siRNA content(%) can be calculated to [(total siRNA amount-free siRNA amount)/total siRNA amount]x100%.
Conclusion: This method was validated according to the guidelines of International Conference on Harmonization (ICH) and showed to be high specific, precise and accurate. And it is also sensitive and does not need additional sample preparations.
Jiyeong Kim– Deputy Senior Manager, Instrument analysis/ R&D center/ Samyang Biopharmaceuticals corp., Seongnamsi, Kyonggi-do, Republic of Korea
kyujin Kyung– Seongnam-si, Kyonggi-do, Republic of Korea
Sukyen Ko– Samyang Biopharmaceuticals Corporation, Seongnam, Kyonggi-do, Republic of Korea