Improving Transungual Permeation Study Design by Increased Bovine Hoof Membrane Thickness and Subsequent Infection

Ungual formulations are regularly tested using human nails or animal surrogates in Franz diffusion cell experiments. Membranes sometimes less than 100 µm thick are used, disregarding the higher physiological thickness of human nails and possible fungal infection. In this study, bovine hoof membranes, healthy or infected with Trichophyton rubrum, underwent different imaging techniques highlighting that continuous pores traversed the entire membrane and infection resulted in fungal growth, both superficial, as well as in the membrane’s matrix. These membrane characteristics resulted in substantial differences in the permeation of the antifungal model substance bifonazole, depending on the dosage forms. Increasing the thickness of healthy membranes from 100 µm to 400 µm disproportionally reduced the permeated amount of bifonazole from the liquid and semisolid forms and allowed for a more pronounced assessment of the effects by excipients, such as urea as the permeation enhancer. Similarly, an infection of 400-µm membranes drastically increased the permeated amount. Therefore, the thickness and infection statuses of the membranes in the permeation experiments were essential for a differential readout, and standardized formulation-dependent experimental setups would be highly beneficial.

DEVELOPMENT OF METRONIDAZOLE MICROSPONGE INCORPORATED INTO CARBOMER-BASED VAGINAL GEL

Bacterial vaginosis (BV) is a vaginal infection caused by excessive bacterial growth, thus disrupting the natural balance of bacteria inside the vagina. Metronidazole becomes a drug of choice and a widely prescribed drug for the treatment of BV. However, when applied topically, metronidazole has a low vaginal residence time because of the natural washing mechanism of the vagina. This study aimed to improve the retention time of metronidazole inside the vagina and control its release profile. This study was prepared 4 formulas of gel for metronidazole microsponges with some concentration ratio of carbomer and triethanolamine. The evaluations carried out to test the efficacy of the developed formulation included organoleptic, pH measurement, spreadability, viscosity, mucoadhesive properties, permeation test using Franz diffusion cell and retention test. The results showed that the gel appearance was white, odourless and homogenous. The characteristics of all prepared gel for pH, viscosity, spreadability, and mucoadhesive ability were appropriate to the required standard for vaginal delivery. The permeation and retention test showed that F3 with the carbomer and triethanolamine concentration of 1.25%: 1.75% was able to retain and controlled the drug release locally in the vaginal mucosa. This study provides an alternative strategy in drug formulation for the treatment of BV.

THE EVALUATION OF ACTIVITY AND STABILITY OF ISOLATED BROMELAIN FROM PINEAPPLE CORES (ANANAS COMOSUS [L.] MERR) AND IN VITRO PENETRATION TEST OF NANOEMULSION TOPICAL BASE

Objective: Oral administration of bromelain as an anti-inflammation therapy still faces several challenges, such as the risk of contact with the gastric fluid and its low absorption rate. Therefore, bromelain isolated from the pineapple core will be formulated as a topical base in a nanoemulsion to increase its stability, activity, and ability to penetrate the skin. Methods: Bromelain was isolated from pineapple core using ammonium sulfate precipitation and dialysis, and then the isolated fraction was loaded into topical nanoemulsion for subsequent evaluation of its characteristics, stability, enzymatic activity, and for in vitro study of penetration using Franz diffusion cell. Results: The highest specific activity of bromelain fractions found in ammonium sulfate concentration is around 20–50%. After being dialyzed, the bromelain fraction showed an increase in specific activity 2.78-fold as compared to crude extract. The characteristics of bromelain nanoemulsion showed a globule size of 21.37±1.8 nm with a polydispersity index (pdI) 0.323±0.049, oil in water (o/w) type, and the type of rheology was plastic flow. The nanoemulsion stability base was observed, and there was no phase separation after centrifugation. Bromelain in nanoemulsion base showed a proteolytic activity of 5.00 U/ml with a protein content of 154.28 mg/l. In vitro penetration studies using Franz diffusion cell for 8 h showed isolated bromelain in nanoemulsion base has a total cumulative number value of 1386.94 μg/cm2 with penetrated velocity/flux (J) of 45.93 μg/cm2 h. Conclusion: The results showed promise for bromelain loaded into nanoemulsion as a vehicle for topically administered therapeutic enzymes.

ASSESSMENT OF PERMEABILITY BEHAVIOR OF BERBERINE CHLORIDE ACROSS GOAT INTESTINAL MEMBRANE IN PRESENCE OF NATURAL BIOPOTENTIATOR CURCUMIN

The present study investigates the influence of co-administration of different concentrations (2, 6, and 10 mg) of curcumin on goat intestinal permeability of berberine chloride (BBC) using Franz diffusion cell. Data obtained in triplicate from permeability studies were used to calculate percentage cumulative drug release (% CDR), apparent permeability (Papp), flux (J) and enhancement ratio (ER). Co-administration of 6 mg concentration of curcumin with BBC was found to be optimum to enhance the permeability of BBC up to 23.92 ± 0.78 % CDR, over control (8.49 ± 1.45 % CDR). At the optimized concentration of curcumin, permeability characteristics were improved significantly compared to control. The present study reveals the beneficial effect of co-administration of curcumin (6 mg) to promote membrane permeability of BBC which would be expected to improve its bioavailability, thereby therapeutic efficacy. The effect could be attributed to curcumin-mediated inhibition of intestinal efflux pump P-gp, acting as an absorption barrier for BBC.

Effects of Transcutol P and Precirol ATO-5 on Percutaneous Absorption of Flutamide from Emulgels

Background: Flutamide is a non-steroidal anti-androgenic agent which is not only used in treating prostate cancer but also can be effective in some disorders such as androgenic alopecia and male pattern baldness. Several serious side effects for systemic administration of flutamide can be overcome by emulgel dosage form. Absorption enhancers can promote permeation of flutamide through skin. Percutaneous absorption of Flutamide emulgels with different concentrations of Transcutol P and Precirol ATO5 was studied. Methods: Various emulgel formulations using different concentration of Transcutol P and Precirol ATO5 with 0.5 to 5 % w/w were prepared. Percutaneous absorption was tested with standard Franz Diffusion Cell equipment using full thickness rat skin. Drug concentrations in the samples were analyzed by High-Performance Liquid Chromatography (HPLC) equipped with UV-Vis detector at 305 nm. Results: The percutaneous absorption of flutamide emulgels formulated with enhancers was higher than control formulations. Enhancement ratio increased from 1.218 to 3.670 and 1.346 to3.900 for Precirol ATO5 and Transcutol P, respectively. Area under the Curve (AUC) increased by increase the enhancers’ concentration and a significant upsurge was seen in the concentration 1% for both enhancers. Conclusion: The flutamide emulgel containing 1% Transcutol P showed more appropriate percutaneous absorption through the skin compared to others.

Medicsen Smartpatch: A New Approach to Diabetes Management

Introduction: Diabetes is a metabolic disorder characterized by a dysregulation of the glucose levels. With insulin being the main drug to be administrated for glucose levels modulation, it needs to be injected subcutaneously with daily injections, which can lead to poor patient compliance, apart from several side-effects. Although other administration methodologies have been investigated (oral or inhaled insulin), they show enough drawbacks to not to be consider as feasible alternatives for diabetes therapy. That′s why Medicsen has developed a Smartpatch that integrates a wide range of technologies, with the purpose of ensuring the correct insulin delivery from the skin′s surface to the bloodstream using a non-invasive and painless drug delivery method through a phenomenon induced by sonophoresis. Materials and Methods: Several in vitro and in vivo tests have been performed to prove the efficacy and safety of the technology, allowing us to collect experimental evidence through different methodologies that demonstrate the therapeutic potential of the device. Among these methodologies, permeability studies using Franz diffusion Cell and swine models (that prove efficacy of the technology) as well as safety studies, for both the insulin and the skin are highlighted. Results: In voltage experiments, the mean time for the disappearance of the membrane potential between the compartments separated by skin was: 334.7 (SD+/-103.6) seconds. Regarding the slope of the voltage line, as an approximation to the transfer speed, an arithmetic mean of (μ)= 0.0164 Mvolts/sec (+/- SD(σ): 0.006) was obtained. No significant differences were found between the circular dichroism spectra of samples (minimum peak at 219nm (sd+/-8.31) and that of the standard, which suggests that the molecular structure of insulin maintains stability. In the same way, HPLC studies shows no variability between the standard and all groups tested. Regardin skin safety, SEM images shows no significant damage to the skin, and ELISA test for TNF α and IL-2, as well as other biochemical tests, show no differences between control and samples. On In vivo experiments with our technology, glucose changes are comparable to those evoked through direct drug injection using conventional syringes. Lastly, the technology proved to be effective in the delivery of insulin through the skin in a non-invasive way, as observed in a Franz Diffusion Cell system and in the in vivo model of blood glucose reduction. Conclusions: Results observed during in vitro and in vivo studies indicate that the technology developed by Medicsen is effective and safe for the patient and the insulin. Following steps, including human trials, will be critical to fully demonstrate its potential in the treatment of diabetes.

Effect of Application Amounts on In Vitro Dermal Absorption Test Using Caffeine and Testosterone

Dermal absorption of chemicals is a key factor in risk assessment. This study investigated the effects of different amounts of application on dermal absorption and suggested an appropriate application dose for proper dermal absorption. Caffeine and testosterone were chosen as test compounds. An in vitro dermal absorption test was performed using a Franz diffusion cell. Different amounts (5, 10, 25, and 50 mg (or µL)/cm2) of semisolid (cream) and liquid (solution) formulations containing 1% caffeine and 0.1% testosterone were applied to rat and minipig (Micropig®) skins. After 24 h, the concentrations of both compounds remaining on the skin surface and in the stratum corneum, dermis and epidermis, and receptor fluid were determined using LC-MS / MS or HPLC. Dermal absorption of both compounds decreased with increasing amounts of application in both skin types (rat and minipig) and formulations (cream and solution). Especially, dermal absorptions (%) of both compounds at 50 mg (or µL)/cm2 was significantly lower compared to 5 or 10 mg (or µL)/cm2 in both rat and minipig skins. Therefore, a low dose (5 or 10 mg (or µL)/cm2) of the formulation should be applied to obtain conservative dermal absorption.

Effect of Penetration Enhancers on Toenail Delivery of Efinaconazole from Hydroalcoholic Preparations

The incorporation of permeation enhancers in topical preparations has been recognized as a simple and valuable approach to improve the penetration of antifungal agents into toenails. In this study, to improve the toenail delivery of efinaconazole (EFN), a triazole derivative for onychomycosis treatment, topical solutions containing different penetration enhancers were designed, and the permeation profiles were evaluated using bovine hoof models. In an in vitro permeation study in a Franz diffusion cell, hydroalcoholic solutions (HSs) containing lipophilic enhancers, particularly prepared with propylene glycol dicaprylocaprate (Labrafac PG), had 41% higher penetration than the HS base. Moreover, the combination of hydroxypropyl-β-cyclodextrin with Labrafac PG further facilitated the penetration of EFN across the hoof membrane. In addition, this novel topical solution prepared with both lipophilic and hydrophilic enhancers was physicochemically stable, with no drug degradation under ambient conditions (25 °C, for 10 months). Therefore, this HS system can be a promising tool for enhancing the toenail permeability and therapeutic efficacy of EFN.

Transdermal delivery of FITC-Dextrans with different molecular weights using radiofrequency microporation

Background Transdermal delivery is of great importance for the effective delivery of bioactive or therapeutic agents into a body. The microporation device based on radiofrequency can be used to enhance delivery efficiency by removing the epidermis layer. Methods The micropores were developed on pig skin and human cadaver skin with dermal and epidermal layers by the microporation device. The regeneration of micropores in the human cadaver skin caused by microporation was confirmed using an optical microscope and haematoxylin/eosin (H&E) staining. The permeability of fluorescein isothiocyanate-dextrans (FITC-dextrans) with different molecular weights through the pig and human cadaver skins were measured using Franz diffusion cell. Results The optical image and histological analysis confirmed that the micropores on the skin were recovered over time. The enhanced permeability through micropores was confirmed by Franz diffusion cell. The lower molecular weight of FITC-dextran permeated more on both human and pig skin. In addition, the permeation rate was higher in pig skin than in human skin. Conclusions We believe that the microporation device can be used as a potential technique for effective transdermal drug delivery.