Quantification of uptake and clearance of acyclovir in skin layers

Feasibility of Enhancing Skin Permeability of Acyclovir through Sterile Topical Lyophilized Wafer on Self-Dissolving Microneedle-Treated Skin

Acyclovir is an antiviral drug that is frequently prescribed for the herpes virus. However, the drug requires frequent dosing due to limited bioavailability (10–26.7%). The rationale of the present study was to develop a self-dissolving microneedle system for local and systemic delivery of acyclovir using a topical lyophilized wafer on microneedle-treated skin to provide the drug at the site of infection. The microneedles prepared with hydroxypropyl methylcellulose (HPMC) (8% w/w) or HPMC (8% w/w)-polyvinyl pyrrolidone (PVP) (30% w/w) penetrated excised rat skin, showing sufficient mechanical strength and rapid polymer dissolution. The topical wafer was prepared with acyclovir (40% w/w; equivalent to 200 mg of drug), gelatin (10% w/w), mannitol (5% w/w), and sodium chloride (5% w/w). The uniform distribution of acyclovir within the wafer in an amorphous form was confirmed by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). No polymer–drug interaction was evident in the lyophilized wafer as per Fourier transform infrared spectroscopy (FTIR) analysis. The wafer showed a sufficiently porous structure for rapid hydration as per scanning electron microscopy (SEM) analysis. During ex-vivo analysis, the skin was pre-treated with a self-dissolving microneedle array for 5 minutes, and the wafer was placed on this microporated-skin. Topical wafer provided ∼7–11 times higher skin concentration than the ID₉₉ reported with a lower lag-time. Based on in-vivo testing, ∼2.58 µg/ml of Cmax was achieved in rabbit plasma during 24 hours’ study. Our findings suggest that the self-dissolving microneedle-assisted topical wafer, proposed for the first time, would be efficacious against the infection residing in the skin layer and for systemic therapy.

Pluronic F127-tailored lecithin organogel of acyclovir: preclinical evidence of antiviral activity using BALB/c murine model of cutaneous HSV-1 infection

Herpes is a well-known contagious infection equally affecting both sexes. Among many antiviral drugs employed for its treatment, acyclovir (ACY) is the drug of choice. The currently available therapies of ACY suffer from limitations like poor oral bioavailability (10-15%) and high-dose requirement. The present scientific study aims to explore pluronic lecithin organogel (PLO) as a novel drug delivery platform for ACY to bring an improvement in its delivery through topical route. The properties of organogel like biocompatibility and amphiphilic nature which facilitates dissolution of various drugs of different solubility characteristics along with enhancing the permeation potential of active molecules make it a favorable drug delivery platform for the management of topical diseases. The developed PLO formulations were characterized for micromeritic characteristics, viz., zeta potential, percentage drug content, organogel morphology, skin permeation, retention, and stability studies. The selected topical formulation was further compared with the marketed one for its therapeutic efficacy by inducing cutaneous Herpes simplex virus type 1 infection followed by confirmation of viral load by immunofluorescence and PCR analyses. The developed formulation showed significant improvement over the marketed product as reflected in lesion scoring index and PCR analysis. Further, it proved better to the marketed formulation in t.i.d. treatment regimen in comparison to control. The improvement in overall performance leading to enhanced bioavailability and safety is attributed to the synergism between excipient properties and formulation characteristics. The drug ACY in this micro environment not only finds an improved delivery vehicle but it also offers enhanced drug-target interactions.

Transdermal Film Loaded with Garlic Oil-Acyclovir Nanoemulsion to Overcome Barriers for Its Use in Alleviating Cold Sore Conditions

The exponentially mounting cases of herpes simplex virus infection or cold sores have become a serious global concern. Acyclovir (ACV) and garlic oil (GO)-loaded lipid nanocarrier could be a promising therapeutic approach in alleviating cold sores, as well as limiting the biopharmaceutical constraints associated with ACV absorption and therapeutic efficacy. Therefore, the objective of the current research study was to formulate an ACV-GO self-nanoemulsifying drug delivery system (ACV-GO-SNEDDS) as transdermal films. The prepared SNEDDS was optimized using an experimental mixture design. The optimized ACV-GO SNEDDS was loaded in transdermal film and was evaluated for ex vivo skin permeation and in vivo pharmacokinetic prospects. An optimized ACV-GO SNEDDs formulation constituted of 10.4% (w/w) of GO, 64.8% (w/w) of surfactant mixture (Tween 20^®-Span 20^®); 24.8%(w/w) of co-surfactant (Propylene glycol^®), and 200mg of ACV, respectively, were prepared and characterized for particle size (Y). The observed globule size of the optimized ACV-GO SNEDDS is 170 ± 13.45 nm. The results of stability studies indicated that the stability index of optimized ACV-GO-SNEDDS was more than 92 ± 3%. This optimized ACV-GO SNEDDS was loaded in hydroxypropyl cellulose transdermal film. The outcome of the ex vivo skin permeation study demonstrated a 2.3-fold augmented permeation of ACV from the optimized ACV-GO SNEDDS HPC transdermal film in comparison to the raw ACV transdermal film. There was a 3-fold increase in the relative bioavailability of the optimized ACV-GO SNEDDS transdermal film compared to the raw ACV-HPC film. The study findings confirmed that the ACV-GO SNEDDS transdermal film exhibited excellent potential to enhance the bioavailability of ACV.

Intranasal delivery of influenza antigen by nanoparticles, but not NKT-cell adjuvant differentially induces the expression of B-cell activation factors in mice and swine

Intranasal vaccination of pigs with poly lactic-co-glycolic acid and polyanhydride nanoparticles delivered inactivated influenza virus provides cross-reactive T-cell response, but not antibody response, resulting in incomplete protection and no reduction in nasal virus shedding. Expression of BAFF and Th2 transcription factor GATA-3 were downregulated in lungs of pigs vaccinated with influenza nanovaccine, but in mice it upregulated the expression of BAFF and cytokine TGFβ in cervical lymph nodes. However, the intranasal iNKT cell adjuvant, α-Galctosylceramide upregulates the expression of BAFF in pig lungs. In conclusion, expression of BAFF is differentially regulated by intranasal nanovaccine and α-Galctosylceramide in pig respiratory tract.