Quantification of Liposomally Incorporated Imidazoquinolines or Oxoadenines using Size Exclusion Chromatography

Authors' Names

Kristopher Short

Presentation Type

Poster Presentation

Abstract/Artist Statement

Imidazoquinolines (IQ) and oxoadenines (OA) are two classes of chemical compounds that are candidates for use as adjuvants in vaccine formulations since they drive specific immune responses through toll-like receptors 7 and 8 (TLR7/8). In order to increase desirable pharmacokinetic properties, IQs and OAs can be chemically modified through the addition of lipid tails and then be stably incorporated into liposomal formulations. Liposomal incorporation could allow more control of delivery of IQs/OAs, including potentially better stability, bioavailability, and efficacy at lower dosage. IQ or OA incorporated liposomes formulations may contain compound incorporated into the liposomal bilayer or existing free in solution as micelles. It is necessary to determine the amount of incorporated and free compound in liposomal formulations to better determine dosage. Traditional reverse phase high pressure liquid chromatography (RP-HPLC) can be used to determine a total amount of IQ/OA in a formulation but gives no information about the fraction of compound incorporated in liposomes compared to free compound existing as micelles. We hypothesize that size exclusion chromatography (SEC) can be used as a novel application to determine IQ/OA dosage within the liposomal or micellular fractions of a formulation.

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Apr 27th, 11:00 AM Apr 27th, 12:00 PM

Quantification of Liposomally Incorporated Imidazoquinolines or Oxoadenines using Size Exclusion Chromatography

UC Ballroom (Center)

Imidazoquinolines (IQ) and oxoadenines (OA) are two classes of chemical compounds that are candidates for use as adjuvants in vaccine formulations since they drive specific immune responses through toll-like receptors 7 and 8 (TLR7/8). In order to increase desirable pharmacokinetic properties, IQs and OAs can be chemically modified through the addition of lipid tails and then be stably incorporated into liposomal formulations. Liposomal incorporation could allow more control of delivery of IQs/OAs, including potentially better stability, bioavailability, and efficacy at lower dosage. IQ or OA incorporated liposomes formulations may contain compound incorporated into the liposomal bilayer or existing free in solution as micelles. It is necessary to determine the amount of incorporated and free compound in liposomal formulations to better determine dosage. Traditional reverse phase high pressure liquid chromatography (RP-HPLC) can be used to determine a total amount of IQ/OA in a formulation but gives no information about the fraction of compound incorporated in liposomes compared to free compound existing as micelles. We hypothesize that size exclusion chromatography (SEC) can be used as a novel application to determine IQ/OA dosage within the liposomal or micellular fractions of a formulation.