Topical delivery of acyclovir and ketoconazole

Improved Subcutaneous Delivery of Ketoconazole Using EpiDerm and HSPiP Software-Based Simulations as Assessed by Cell Viability, Cellular Uptake, Permeation, and Hemolysis In Vitro Studies

Ketoconazole (KETO) is the drug of choice to control local, systemic, and resistant types of fungal infections. Subcutaneous (sub-Q) delivery offers several benefits. The present study investigated the sub-Q delivery of KETO using HSPiP software based on optimized concentrations of dimethylacetamide (DMA) in binary solvents (DMA + water), in vitro cellular uptake (J774A.1) assays, cellular toxicity (L929), and in vitro hemolysis studies. Results showed that the estimated permeation coefficient (9.6 × 10^-3 cm/h) and diffusion coefficient (3.9 × 10^-3 cm²/h) of KETO (22.3 mg) in KF3 (300 mg of DMA + water) across EpiDerm were relatively higher as compared to the other formulations [KF1 (11.2 and 150 mg as KETO and DMA, respectively) and KF2 [(22.3 and 300 mg as KETO and DMA, respectively)] due to the increased content of DMA and KETO. HSPiP simulated and predicted the impact of constant and variable diffusion coefficients on the percent drug absorption across EpiDerm and the time needed to achieve equilibrium. The concentration-dependent diffusion coefficient fed into HSPiP predicted that the drug absorption and permeation values were linearly dependent on the square root of time. The HSPiP predicted permeation flux values from KF3, KF2, and KF1 across the EpiDerm were 4.07 × 10^-6, 4.01 × 10^-6, and 1.1 × 10^-6 g/cm²/s, respectively, at respective D range values. The selected K30G (324 mOsm/Kg) showed an optimal pH (6.9) and minimum drug loss (0.01%) over a period of 1 month at room temperature. KG30 was found to be less toxic to normal L292 cells and caused maximum cytotoxicity to candida cells residing within infected macrophage cells (J774A.1 incubated for 24 h), which was attributed to the slow diffusion of K30G compared to DS (the drug solution with an equivalent concentration). KG30 elicited substantial internalization with candida albicans (MTCC 4748) compared to the control group (24 h). Lastly, in vitro hemolysis studies (1 and 5 μg/mL) corroborated the safety of K30G for sub-Q delivery. Therefore, this new formulation and approach for delivering KETO is a promising alternative to conventional products to control fungal infections and, thus, should be further studied in vivo.

CaCO3-based carriers with prolonged release property for antifungal drug delivery to hair follicles

Superficial fungal infections are of serious concern worldwide due to their morbidity and increasing distribution across the globe in this era of growing antimicrobial resistance. Delivery of antifungals to target...

Experimental Solubility of Ketoconazole, Validation Models, and In vivo Prediction in Human Based on GastroPlus

The study aimed to identify a suitable cosolvent + water mixture for subcutaneous (sub-Q) delivery of ketoconazole (KETO). The solubility was assessed for several dimethyl acetamide (DMA) + water mixtures at T = 293.2 to 318.2 K and pressure P = 0.1 MPa. The experimental solubility (x_e) was validated using the Van 't Hoff and Yalkowsky models and functional thermodynamic parameters (enthalpy Δ_solH°, entropy Δ_solS°, and Gibbs free energy Δ_solG°). The in vitro drug release study was performed at physiological pH, and the data served as the input to GastroPlus, which predicted the in vivo performance of KETO dissolved in a DMA + water cosolvent mixture for sub-Q delivery in human. The maximum solubility (mole fraction) of KETO (9.81 × 10^-1) was obtained for neat DMA at 318.2 K whereas the lowest value (1.7 × 10^-5) was for pure water at 293.2 K. An apparent thermodynamic analysis based on x_e gave positive values for the functional parameters. KETO dissolution requires energy, as evidenced by the high positive values of Δ_solH° and Δ_solG°. Interestingly, Δ_solG° progressively decreased with increasing concentration of DMA in the DMA + water mixture, suggesting that the DMA-based molecular interaction improved the solubilization. Positive values of Δ_solG° and Δ_solS° for each DMA + water cosolvent mixture corroborated the endothermic and entropy-driven dissolution. GastroPlus predicted better absorption of KETO through sub-Q delivery than oral delivery. Hence, the DMA + water mixture may be a promising system for sub-Q delivery of KETO to control topical and systemic fungal infections.

Thermodynamic, Computational Solubility Parameters in Organic Solvents and In Silico GastroPlus Based Prediction of Ketoconazole

The study aimed to select a suitable solvent capable to solubilize ketoconazole (KETO) and serve as a permeation enhancer across the skin. Experimental solubility and Hansen solubility parameters were obtained in ethanol, dimethyl sulfoxide (DMSO), ethylene glycol, oleic acid, span 80, limonene, eugenol, transcutol (THP), labrasol, and propylene glycol. Thermodynamic functional parameters and computational models (van't Hoff and Apelblat) validated the determined solubility in various solvents at T = 298.2 K to 318.2 K and P = 0.1 MPa. The HSPiP software estimated the solubility parameters in the solvents. The maximum mole fractional solubility values of KETO were found to be in an order as oleic acid (8.5 × 10-3) > limonene (7.3 × 10-3) > span 80 (6.9 × 10-2) > THP (4.9 × 10-2) > eugenol (4.5 × 10-3) at T = 318.2 K. The results of the apparent thermodynamic analysis confirmed that the dissolution rate was endothermic and entropy driven. The GastroPlus program predicted significantly high permeation of KETO (79.1%) in human skin from the KETO-THP construct as compared to drug solution (38%) and excellent immediate release from THP-solubilized construct (90% < 1 h). Hence, THP could be a better option for topical, transdermal, and oral formulation.

Development and Evaluation of Polymeric Nanosponge Hydrogel for Terbinafine Hydrochloride: Statistical Optimization, In Vitro and In Vivo Studies

Terbinafine hydrochloride, although one of the prominent antifungal agents, suffers from low drug permeation owing to its hydrophobic nature. The approach of nanosponge formulation may thus help to resolve this concern. Thus, the present research was envisioned to fabricate the nanosponge hydrogel of terbinafine hydrochloride for topical delivery since nanosponge augments the skin retentivity of the drug. The optimized formulation was obtained using Box Behnken Design. The dependent and independent process parameters were also determined wherein polyvinyl alcohol (%), ethylcellulose (%), and tween 80 (%) were taken as independent process parameters and particle size, polydispersity index (PDI), and entrapment efficiency (EE) were the dependent parameters. The nanosponge was then incorporated into the hydrogel and characterized. In-vitro drug release from the hydrogel was 90.20 ± 0.1% which was higher than the drug suspension and marketed formulation. In vitro permeation potential of the developed formulation through rat skin showed a flux of 0.594 ± 0.22 µg/cm²/h while the permeability coefficient was 0.059 ± 0.022 cm/s. Nanosponge hydrogel was evaluated for non-irritancy and antifungal activity against C. albicans and T. rubrum confirming the substantial outcome. Tape stripping studies exhibited ten times stripping off the skin quantified 85.6 ± 0.21 μg/cm². The confocal analysis justified the permeation potential of the prepared hydrogel. The mean erythemal score was 0.0, confirming that the prepared hydrogel did not cause erythema or oedema. Therefore, based on results obtained, nanosponge hydrogel formulation is a potential carrier for efficient topical delivery of terbinafine hydrochloride.

Ionic liquids containing ketoconazole improving topical treatment of T. Interdigitale infection by synergistic action

This study aimed to exert the synergistic action of ketoconazole (KCZ) and ionic liquids (ILs) for improving antifungal effect. Various ILs were engineered and demonstrated different solubilization capacity for KCZ. Among them, the IL formed by choline and geranic acid ([Ch][Ger]) was the optimal one and able to imporve the solubility of KCZ by around 100-fold. The in vitro antifungal test revealed the [Ch][Ger] significantly inhibited the activity of T. Interdigitale and exerted the synergistic action with KCZ. Compared to Daktarin®, the [Ch][Ger] not only promoted KCZ to penetrate into deep skin layer but also improved in vivo anti-T. Interdigitale activity significantly. Besides, the [Ch][Ger] was able to strip the skin of the lesion site in a flaky manner to remove fungi more thoroughly. However, the skin can recover to be normal state after treatment and there was no evident skin irritation found in [Ch][Ger] group. The ILs may offer promising opportunities to deliver anti-fungal drugs to treat inner skin fungal infections by synergistic action.

Formulation and optimization of microsponge-loaded emulgel to improve the transdermal application of acyclovir-a DOE based approach

The cutaneous penetration of acyclovir from the conventional topical formulations such as cream and ointments is poor due to low water solubility and low octanol buffer partition coefficient of the drug. The present investigation was aimed to prepare acyclovir-loaded microsponge-based emulgel to improve its topical delivery. The microsponges were prepared by the quasi-emulsion diffusion method. The central composite design was employed to investigate the effect of changes in various formulation and process parameters on critical product attributes. Homogenization speed (X1), drug/polymer ratio (X2), and concentration of PVA (X3) were selected as independent variables while particle size,b% yield, % drug loading efficiency, % entrapment efficiency, the drug released at 0.25 h and 6 h were selected as response variables. The regression analysis proved a significant effect of all the independent variables on the dependent variables (p < 0.05). All the designed batches released more than 40% drug in less than 1 h and were also able to sustain the drug release for more than 6 h. Based on the solution suggested by the software, the optimized batch was prepared with 1000-rpm homogenization speed, 1.6:1 drug/polymer ratio, and 0.088% of PVA. The optimized microsponge-loaded emulgel had acceptable viscosity (10,897 to 12,416 centipoise), spreadability (32.5 to 36.57 g × cm/s), pH (between 6 and 7), and drug content (93 to 95%). The results of the ex vivo permeation study proved significant improvement in drug permeation from optimized microsponge-loaded emulgel compared to the marketed formulation (f2 < 50).

PEGylated Lipid Polymeric Nanoparticle-Encapsulated Acyclovir for In Vitro Controlled Release and Ex Vivo Gut Sac Permeation

Currently, pharmaceutical research is directed wide range for developing new drugs for oral administration to target disease. Acyclovir formulation is having common issues of short half-life and poor permeability, causing messy treatment which results in patient incompliance. The present study formulates a lipid polymeric hybrid nanoparticles for antiviral acyclovir (ACV) agent with Phospholipon® 90G (lecithin), chitosan, and polyethylene glycol (PEG) to improve controlled release of the drugs. The study focused on the encapsulation of the ACV in lipid polymeric particle and their sustained delivery. The formulation developed for the self-assembly of chitosan and lecithin to form a shell encapsulating acyclovir, followed by PEGylation. Optimisation was performed via Box-Behnken Design (BBD), forming nanoparticles with size of 187.7 ± 3.75 nm, 83.81 ± 1.93% drug-entrapped efficiency (EE), and + 37.7 ± 1.16 mV zeta potential. Scanning electron microscopy and transmission electron microscopy images displayed spherical nanoparticles formation. Encapsulation of ACV and complexity with other physical parameters are confirmed through analysis using Fourier transform infrared spectroscopy, differential scanning calorimetry, and X-ray diffraction. Nanoparticle produced was capable of achieving 24-h sustained release in vitro on gastric and intestinal environments. Ex vivo study proved the improvement of acyclovir's apparent permeability from 2 × 10-6 to 6.46 × 10-6 cm s-1. Acyclovir new formulation was achieved to be stable up to 60 days for controlled release of the drugs. Graphical abstract.

Colloidal lipid nanodispersion enriched hydrogel of antifungal agent for management of fungal infections: Comparative in-vitro, ex-vivo and in-vivo evaluation for oral and topical application

Ketoconazole (KZ) is broad spectrum antifungal drug, used for the treatment of fungal infections. KZ's clinical topical use has been associated with some adverse effects in healthy adults particularly local reactions, such as stinging, severe irritation, and pruritus. However, bioavailability of KZ after oral administration is low from tablets due to its low aqueous solubility. The objective of this investigation was development and characterization of KZ-containing solid lipid nanoparticles (KZ-SLNs) and SLN-containing hydrogel (KZ-SLN-H) for oral and topical delivery of KZ. KZ-SLNs were prepared using homogenization-sonication method. Optimal KZ-SLN formulation was selected based on physicochemical and in-vitro release studies. Optimized KZ-SLN converted to KZ-SLN hydrogel (KZ-SLN-H) using gelling polymers and optimized with rheological and in-vitro studies. Further, optimized KZ-SLN and KZ-SLN-H formulations evaluated for crystallinity, morphology, stability, ex-vivo and in-vivo pharmacokinetic (PK) studies in rats, comparison with KZ suspension (KZ-S) and KZ-S hydrogel (KZ-SH). Optimized KZ-SLN formulation showed desirable characters. KZ-SLN and KZ-SLN-H formulations exhibited spherical shape, converted to amorphous, sustained release behaviour and enhanced permeability (p < 0.05). Moreover, both formulations were stable for three months at 4 °C and 25 °C. PK studies revealed 1.9 and 1.5-folds, 3.5 and 2.8-folds enhancement of bioavailability of optimized KZ-SLN and KZ-SLN-H formulations (p < 0.05) compared with KZ-S and KZ-SH formulations, respectively. Overall, SLN and SLN-H formulations could be considered as an efficient delivery vehicles for KZ through oral and topical administration for better control over topical and systemic fungal infections.

Identification of critical formulation parameters affecting the in vitro release, permeation, and rheological properties of the acyclovir topical cream

To understand effects of formulation variables on the critical quality attributes (CQA) of acyclovir topical cream, this study investigated effects of propylene glycol (PG), poloxamer, and sodium lauryl sulfate (SLS) concentrations, acyclovir particle size, and formulation pH of the acyclovir cream. Fifteen formulations were prepared and characterized for rheological properties, particle size distribution, drug release and in vitro skin permeation. Drug distribution between various phases of the cream was determined. The concentration of soluble acyclovir in the aqueous phase was determined as a surrogate of the equilibrium with other acyclovir species in the cream. The interaction among effects of the formulation variables on the amount of acyclovir retained by skin was also evaluated. The results showed that PG significantly (p < 0.05) increased the yield stress, viscosity, drug concentration in the aqueous phase, and drug release. The PG and SLS significantly (p < 0.05) increased acyclovir retention by skin samples. Particle size of acyclovir inversely affected the drug release. This study revealed that the employed concentrations of PG and SLS and particle size of the dispersed acyclovir are critical formulation variables that should be carefully controlled when developing acyclovir topical creams with desired performance characteristics.

Microphysiological heart-liver body-on-a-chip system with a skin mimic for evaluating topical drug delivery

Body-on-a-chip in vitro systems are a promising technology that aims to increase the predictive power of drug efficacy and toxicity in humans when compared to traditional animal models. Here, we developed a new heart-liver body-on-a-chip system with a skin surrogate to assess the toxicity of drugs that are topically administered. In order to test the utility of the system, diclofenac, ketoconazole, hydrocortisone and acetaminophen were applied topically through a synthetic skin surrogate (Strat-M membrane) and the toxicity results were compared to those of acute drug exposure from systemically applying the compounds. The heart-liver system was successful in predicting the effects for both cardiac and liver functions changes due to the compounds. The difference in the concentrations of drugs applied topically compared to systemically indicates that the barrier properties of the skin surrogate were efficient. One important advantage of this heart-liver system was the capability of showing differential effects of acute and chronic drug exposure which is necessary as part of the International Conference in Harmonisation (ICH) tri-partate guidelines. In conclusion, this work indicates a promising heart-liver body-on-a-chip system that can be used for the assessment of potential drug toxicity from dermal absorption as well as evaluate transport dynamics through the skin in the same system.

Efficacy of ketoconazole gel-flakes in treatment of vaginal candidiasis: Formulation, in vitro and clinical evaluation

Candida albicans, as the main causative fungus of vaginal candidiasis, is currently a global issue of concern due to its high prevalence, biofilm formation and emergence of resistance. Ketoconazole (KTZ), an antifungal drug, which has poor water-solubility and penetration capacity, is ineffective against deep-seated Candida infection. Considering these issues, this work aimed to develop a novel multifunctional carrier for KTZ via encapsulation of KTZ/β-cyclodextrin (β-CD) co-ground mixture into chitosan/gellan gum gel-flakes (threadlike and polygonal structures). Analytical studies revealed existence of electrostatic-derived complexes between negatively charged gellan gum and positively charged chitosan. Gel-flakes were then loaded in in situ gel of pluronic F-127 (PF-127). Based on gelation temperature (T_gel), viscosity and release studies; selected formulation was further evaluated, showing significant in vitro anti-candida activity. Despite reduced dosage regimen (50 mg/daily/three days), KTZ flakes in situ gel was as effective as Gynoconazol vaginal cream® (80 mg terconazole/daily/three days) in improving patient complaints and Candida eradication. Multifunctionality of KTZ carrier was based on efficient spreading and coating of the vagina due to free-flowing properties during application, flakes entanglement within folded vaginal epithelia, sustained release and increased penetration capacity of KTZ to reach deep-seated infections. In conclusion, flakes in situ gel could be considered as a highly promising KTZ delivery option for treatment of vaginal candidiasis.

Potential Application of Nanoemulsions for Skin Delivery of Pomegranate Peel Polyphenols

Pomegranate peel and seeds have demonstrated to possess antioxidant compounds with potential application to protect the skin against the ultraviolet radiation damage. However, the photoprotection activity is dependent on the amount of these compounds that reach the viable skin layers. In this paper, we describe the in vitro skin permeation and retention of the major pomegranate peel polyphenols using Franz diffusion cells, after entrapping a ethyl acetate fraction (EAF) from Punica granatum peel extract into nanoemulsions (NEs) prepared with pomegranate seed oil (PSO) or medium chain triglyceride oil (MCT). The in vitro skin permeation of gallic acid (GA), ellagic acid (EA), and punicalagin (PC) was evaluated using a HPLC-DAD validated method. After 8 h of skin permeation, all polyphenol compounds were mostly retained in the skin and did not reach the receptor compartment. However, a 2.2-fold enhancement of the retained amount of gallic acid in the stratum corneum was verified after EAF-loaded NEs are applied, when compared with the free EAF. GA and EA were delivered to the viable epidermis and dermis only when nanoemulsions were applied onto the skin. The mean retained amounts of GA and EA in the EP and DE after applying the EAF-loaded PSO-NE were 1.78 and 1.36 μg cm^-2 and 1.10 and 0.97 μg cm^-2, respectively. Similar values were obtained after applying the EAF-loaded MCT-NE. The skin permeation results were supported by the confocal microscopy images. These results evidenced the promising application of nanoemulsions to deliver the pomegranate polyphenols into the deeper skin layers.

Novel reverse electrodialysis-driven iontophoretic system for topical and transdermal delivery of poorly permeable therapeutic agents

Topical and transdermal drug delivery has great potential in non-invasive and non-oral administration of poorly bioavailable therapeutic agents. However, due to the barrier function of the stratum corneum, the drugs that can be clinically feasible candidates for topical and transdermal delivery have been limited to small-sized lipophilic molecules. Previously, we fabricated a novel iontophoretic system using reverse electrodialysis (RED) technology (RED system). However, no study has demonstrated its utility in topical and/or transdermal delivery of poorly permeable therapeutic agents. In this study, we report the topical delivery of fluorescein isothiocyanate (FITC)-hyaluronic acid (FITC-HA) and vitamin C and the transdermal delivery of lopinavir using our newly developed RED system in the in vitro hairless mouse skin and in vivo Sprague-Dawley rat models. The RED system significantly enhanced the efficiency of topical HA and vitamin C and transdermal lopinavir delivery. Moreover, the efficiency and safety of transdermal delivery using the RED system were comparable with those of a commercial ketoprofen patch formulation. Thus, the RED system can be a potential topical and transdermal delivery system for various poorly bioavailable pharmaceuticals including HA, vitamin C, and lopinavir.

Delivery of Thermoresponsive-Tailored Mixed Micellar Nanogel of Lidocaine and Prilocaine with Improved Dermatokinetic Profile and Therapeutic Efficacy in Topical Anaesthesia

The topical delivery of local anaesthetics has always been a difficult task due to the limited percutaneous absorption of local anaesthetic drugs across the various barriers of the skin. In this pursuit, a thermoresponsive mixed micellar nanogel (MMNG) system of lidocaine and prilocaine has been attempted in the current piece of work. The system relies on the ability to alter its phase state (sol-to-gel) for feasibility of the topical application in response to change in temperature. The composition of MMNG entails majorly of Pluronic® F127 and Tween 80 in a fixed combination so as to provide the desired thermoreversibility for the skin application. The gels were optimized with respect to phase transition temperature (T _sol/gel), turbidity and viscosity. The optimized systems were then characterized for particle size, spreadability, syringeability, bioadhesive strength, ex vivo skin permeation, retention and dermatokinetic studies. The skin compatibility revealed that no histological changes were observed for optimized formulation, while the conventional system showed changes in the skin-tissues. Further, the enhanced intensity of anaesthetic effect was noted in an in vivo rabbit model and tail flick model in mice. The overall results suggest that the prepared MMNG system possesses the potential in providing an efficacious, safe and acceptable alternative therapeutic system for topical anaesthesia.

Advances in Hybrid Polymer-Based Materials for Sustained Drug Release

The use of biomaterials composed of organic pristine components has been successfully described in several purposes, such as tissue engineering and drug delivery. Drug delivery systems (DDS) have shown several advantages over traditional drug therapy, such as greater therapeutic efficacy, prolonged delivery profile, and reduced drug toxicity, as evidenced by in vitro and in vivo studies as well as clinical trials. Despite that, there is no perfect delivery carrier, and issues such as undesirable viscosity and physicochemical stability or inability to efficiently encapsulate hydrophilic/hydrophobic molecules still persist, limiting DDS applications. To overcome that, biohybrid systems, originating from the synergistic assembly of polymers and other organic materials such as proteins and lipids, have recently been described, yielding molecularly planned biohybrid systems that are able to optimize structures to easily interact with the targets. This work revised the biohybrid DDS clarifying their advantages, limitations, and future perspectives in an attempt to contribute to further research of innovative and safe biohybrid polymer-based system as biomaterials for the sustained release of active molecules.

Methoxy poly (ethylene glycol)-b-poly (δ-valerolactone) copolymeric micelles for improved skin delivery of ketoconazole

Ketoconazole is a broad spectrum imidazole antifungal drug. For the treatment of superficial fungal infections with ketoconazole, it needs to be permeated to deep skin layers. In order to develop topical formulation of ketoconazole for improving its skin deposition and water-solubility, ketoconazole-loaded methoxy poly (ethylene glycol)-b-poly (δ-valerolactone) micelles were developed through thin-film hydration method. Particle size, drug loading capacity, infrared spectrum and X-ray diffraction of drug-loaded micelles were characterized. The optimal drug formulation was selected for skin delivery and deposition investigation performed by use of mice skin, and its in vitro release and antifungal activity were also investigated. Penetration and distribution in the skin were also visualized using fluorescein-loaded micelles and fluorescence microscopy. The drug-loaded micelles were obtained with encapsulation efficiency of 86.39% and particle diameter of about 12 nm. The micelles made ketoconazole aqueous solubility increase to 86-fold higher than crude one. Ketoconazole-loaded micelles showed no skin permeation of ketoconazole, obviously enhance skin deposition and demonstrated similar antifungal activity as compared with marketed ketoconazole cream. Fluorescein-loaded micelles displayed higher skin deposition than fluorescein water solution. These results demonstrate that the MPEG-PVL micelle is a potential delivery system for ketoconazole in the field of skin delivery.

Influence of sonophoresis and chemical penetration enhancers on percutaneous transport of penbutolol sulfate

The effect of ultrasound and chemical penetration enhancers on transcutaneous flux of penbutolol sulfate across split-thickness porcine skin was investigated. Penbutolol sulfate is a potent, noncardioselective beta-blocker, which is used for the management of hypertension. The drug is one of the most lipid soluble of the β-adrenoceptor antagonists used clinically. It has an n-octanol/pH 7.4 buffer partition coefficient of 179 compared to a value of 22 for propranolol. The amount of penbutolol sulfate transported across the skin is low. In this project, we studied the effect of sonophoresis and chemical penetration enhancers on transdermal delivery of penbutolol sulfate. Low-frequency sonophoresis at a frequency of 20 kHz increased transcutaneous flux of penbutolol sulfate by 3.5-fold (27.37 ± μg cm^-2 h^-1) compared to passive delivery (7.82 ± 1.72 μg cm^-2 h^-1). We also investigated the effect of 50% ethanol, 1% limonene and 2% isopropyl myristate (IPM) on transcutaneous permeation of penbutolol sulfate. IPM, ethanol and limonene at the concentration of 1%, 50% and 2%, respectively, increased the steady-state flux values of penbutolol sulfate 2.2- (17.07 ± 3.24 μg cm^-2 h^-1), 2.6 - (19.40 ± 6.40 μg cm^-2 h^-1) and 3.4-times (26.38 ± 5.01 μg cm^-2 h^-1) compared to passive delivery (7.76 ± 2.9 μg cm^-2 h^-1). The results demonstrate that although there were slight increases in flux values, ultrasound, ethanol, limonene and IPM did not significantly enhance the transdermal delivery of penbutolol sulfate. Future studies will examine ways of optimizing sonophoretic and chemical enhancer parameters to achieve flux enhancement.

Synergetic skin targeting effect of hydroxypropyl-β-cyclodextrin combined with microemulsion for ketoconazole

The objective was to develop a ternary skin targeting system for ketoconazole (KET) using a combined strategy of microemulsion (ME) and cyclodextrin (HP-β-CD), i.e., KET-CD-ME, which exploits both virtues of cyclodextrin complex and ME to obtain the synergetic effect. KET-CD-ME was formulated using Labrafil M 1944 CS as oil phase, Solutol HS 15 as surfactant, Transcutol P as cosurfactant, and HP-β-CD solution as aqueous phase. The formulation of KET-CD-ME was optimized and the optimal formulation was characterized in terms of particle size, size distribution, pH value, and viscosity. Long term stability experiment showed that HP-β-CD could increase the physical stability of ternary system and KET chemical stability. Percutaneous permeation of KET from KET-CD-ME in vitro through rat skin was investigated in comparison with KET microemulsion (KET-ME), KET HP-β-CD inclusion solution (KET-CD), KET aqueous suspension, and commercial KET cream; the results showed that the combination of ME with HP-β-CD exhibited significantly synergistic effect on KET deposition within the skin (29.38 ± 1.79 μg/cm(2)) and a slightly synergistic effect on KET penetration through the skin (11.3 μg/cm(2)/h). The enhancement of the combination on skin deposition was further visualized by confocal laser scanning microscope (CLSM). In vitro sensitivity against Candida parapsilosis test indicated that KET-CD-ME enhanced KET antifungal activity mainly owing to the solubilization of HP-β-CD on KET in the ternary system. Moreover, the interactions between HP-β-CD and KET in the ternary system were elucidated through microScale thermophoresis (MST) and 2D (1)H NMR spectroscopy. The profiles from MST confirmed the host-guest interactions of HP-β-CD with KET in the ternary system and a deep insight into the interactions between KET and HP-β-CD were obtained by means of 2D (1)H NMR spectroscopy. The results indicate that the ternary system of ME combination with HP-β-CD may be a promising approach for skin targeting delivery of KET.