Preparation, characterization, and pharmacokinetics study of apocynin and vanillic acid via hydroxypropyl-beta-cyclodextrin encapsulation

Abstract

Apocynin (AP) and vanillic acid (VA) are rich antioxidant has a broad spectrum of pharmacological activities. However, its practical administration has been limited due to poor aqueous solubility and bioavailability. Hence Cyclodextrins are used to improve the solubility and oral bioavailability of AP and VA via Hydroxypropyl beta-cyclodextrin (HPBCD) formulation. HPBCD inclusion complex with AP-VA was synthesized and characterized for its physicochemical properties. The average particle size of HPBCD-AP-VA was 164.1 ± 1.3nm, 146.7 ± 2.0nm, and zeta potential was -30.0 mv and -17.3 mv. The encapsulation `efficiency was found to be 97% and 95%, respectively. AFM, SEM, and TEM confirmed the size, spherical nature, and smooth surface of the inclusion complex. The results of XRD, DSC and FTIR, indicated that AP-VA successfully entered the cavity of HPBCD. In vitro bioaccessibility result revealed that HPBCD inclusions were more accessible when compared to Native form. Further, in vivo bioavailability study showed high concentration of HPBCD-AP-VA complex in plasma (25mg/kg bwt) and compared to Native. The Tmax and AUC of HPBCD complex in plasma was 2h and 253.46 ± 3.42, 249.28 ± 2.31 respectively. The results of the study revealed that using HPBCD to encapsulate AP-VA can be beneficial for the pharmacological uses.