Carrageenan-Acyclovir Complex and Its Liposomal Form

Sulfated polysaccharides, carrageenans (CRGs) derived from Chondrus armatus, were used as mucoadhesive matrices for incorporating the antiviral drug acyclovir (ACV). Through IR spectroscopy and quantum-chemical calculations, it was demonstrated that CRGs interact with ACV, forming complexes via intermolecular hydrogen bonding and coordination interactions, with an enthalpy of approximately 15-20 kcal/mol. The monomodal ζ-potential distribution observed in the CRG/ACV mixture confirmed the successful formation of this complex. The antiviral efficacy of the CRG/ACV complex was evaluated during the early stages of herpes simple virus (HSV-1) infection, focusing on its ability to inhibit the cytopathic effects of the virus on host cells. Notably, CRGs enhanced antiviral activity by allowing a reduction in the ACV dosage. Unlike ACV alone, the CRG complex exhibited a prophylactic effect, with therapeutic efficacy comparable to that of ACV. When incorporated into liposomes, the CRG/ACV complex displayed excellent mucoadhesive properties. This liposomal formulation demonstrated notable antiviral activity against infected cells with selective index (SI) 344 and a heightened prophylactic effect (SI 128) compared to the complex alone. Overall, these new antiviral compounds show promise in selectively inhibiting viral adsorption and replication processes without adversely affecting the host organism.