Oral gel loaded with penciclovir–lavender oil nanoemulsion to enhance bioavailability and alleviate pain associated with herpes labialis

Abstract

Herpes labialis, caused by herpes simplex virus type 1, is usually characterized by painful skin or mucosal lesions. Penciclovir (PV) tablets are found to be effective against herpes labialis but suffer from poor oral bioavailability. This study aimed to combine the benefits of PV and lavender oil (LO), which exhibits anesthetic activity, in the form of a self-nanoemulsifying drug delivery system (SNEDDS) for the treatment of herpes labialis. Toward this purpose, LO (oil), Labrasol:Labrafil M1944 CS in the ratio of 6:4 (surfactant mixture), and Lauroglycol-FCC (co-surfactant, selected based on the solubility of PV) were evaluated as the independent factors using a distance quadratic mixture design. The formulation was optimized for the minimum globule size and maximum stability index and was determined to contain 14% LO, 40.5% Labrasol:Labrafil 1944 (6:4), and 45.5% Lauroglycol-FCC. The optimized PV-LO-SNEDDS was embedded in chitosan hydrogel and the resulting formulations coded by (O3) were prepared and evaluated. The rheological studies demonstrated a combined pseudoplastic and thixotropic behavior with the highest flux of PV permeation across sheep buccal mucosa. Compared to a marketed 1% PV cream, the O3 formulation exhibited a significantly higher and sustained PV release, nearly twice the PV permeability, and a relative bioavailability of 180%. Overall, results confirm that the O3 formulation can provide an efficient delivery system for PV to reach oral mucosa and subsequent prolonged PV release. Thus, the PV-LO-SNEDDS embedded oral gel is promising and can be further evaluated in clinical settings to establish its therapeutic use in herpes labialis.

Nanoemulsions: Formulation, characterization, biological fate, and potential role against COVID-19 and other viral outbreaks

“…Topical administration of NEs has also led to many successful antiviral drug delivery applications. Penciclovir–lavender oil NEs-based gels have shown promising results as topical anti-herpes virus treatments, particularly for herpes labialis disease due to improved skin permeation of protonated surfaces [ 182 ].…”

Development of Chitosan-Based Nanoemulsion Gel Containing Microbial Secondary Metabolite with Effective Antifungal Activity: In vitro and in vivo Characterizations

“…Topically applied transdermal formulations have numerous advantages including site targeting, 11 minimizing side effects associated with oral preparations, 12 high patient acceptance, enhanced patient compliance, and improved therapeutic efficacy. 13 The topical formulations show their efficacy if the drug from these formulations releases and penetrates the layers of skin, which will create an effective drug depot.…”

“… 13 The topical formulations show their efficacy if the drug from these formulations releases and penetrates the layers of skin, which will create an effective drug depot. 12 However, there are some limitations in therapeutic efficacy of several drugs. These may be due to impaired physicochemical properties of the drug substances and dosage forms.…”

“…These are colloidal dispersions having two immiscible liquids which are stabilized by the addition of surfactants or co-surfactants. 12 , 13 Nanoemulsions help to enhance the bioavailability and onset of action of drugs by improving solubility and dissolution. They have the ability to deliver both hydrophilic and hydrophobic drugs as well as to achieve sustained drug release.…”

“…Gels are widely accepted for dermatological application as they possess several favorable properties that include being emollient, non-staining, and easily removable, optimum spreadability, non-greasiness, higher compatibility with several other excipients, water-soluble and pseudo-plastic. 12 Gels can be incorporated into nanoemulsion leading towards the formation of nanoemulgel or nanoemulsion gel. The polymers in gels form a three-dimensional hydrogel network which entrap nanoemulsions globules.…”