Physicochemical Characterization and Clinical Evaluation of Final Formulation of Shallomin Liposomal Gel on Cold Sore

Acyclovir is used locally or systemically to treat cold sore and totally have no side effect. However, this antiviral drug is not suitable for some people. The main aim of this study was to prepare and characterize shallomin liposomal hydrogel formulation and evaluation and comparison of dermal efficacy of this new formulation with acyclovir ointment on cold sores. Thin-Film Hydration was used to prepare liposome consisting of lecithin and cholesterol (molar ratio: 1:1). Morphology, size analysis and liposome encapsulation efficiency were determined. For preparation of hydrogel, Hydroxyethyl cellulose (HEC) was used. In vitro Skin permeation assay through abdominal region skin of male wistar rat was also determined. After preparing liposomal shallomin 1% in hydrogel a randomized controlled trial was performed on three groups (15 students in each groups) who showed cold sore within 24 hours. Liposomal shallomin gel, acyclovir and placebo was used every 6 hours for the first, second and third groups, respectively. The size of liposomal shallomin particles were 139±31.8 nm whereas polydispersity index values were 0.219 ± 0.01. The TEM images showed that the shape of particles was spherical and any aggregation or fusion were not seen. Furthermore, the particle size diameter was < 150 nm. The encapsulation capacity with the liposomes was approximately calculated 82.7%. The cold sore and tingling was disappeared in liposomal shallomin gel treated group within 0-12 hours in 12 cases (80%) and within 12-24 hours in 2 cases. In the acyclovir treated group, skin was cleared from cold sore in 8 cases (53%) within 24-48 hours after using drug. Regarding the obtained results, the liposomal shallomin gel caused a significant improvement in the removing cold sores within 12 hours related to acyclovir (P=0.001). Because mucoidal properties of hydrogel can facilitate adhesion between the shallomin and skin membrane, which extend keeping of shallomin at the site of administration and enhancing drug permeation so, liposomal shallomin gel is more effective treatment than shallomin extract and acyclovir with fewer side effects for cold sores treatment.