Formulation, Preparation, Characterization, and Evaluation of Dicarboxylic Ionic Liquid Donepezil Transdermal Patches

Donepezil (DPZ) is generally administered orally to treat Alzheimer’s disease (AD). However, oral administration can cause gastrointestinal side effects. Therefore, to enhance compliance, a new way to deliver DPZ from transdermal patch was developed. Ionic bonds were created by dissolving dicarboxylic acid and DPZ in ethanol, resulting in a stable ionic liquid (IL) state. The synthesized ILs were characterized by differential scanning calorimetry, optical microscope, Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. The DPZ ILs were then transformed to a suitable drug-in-adhesive patch for transdermal delivery of DPZ. The novel DPZ ILs patch inhibits crystallization of the IL, indicating coherent design. Moreover, DPZ ILs and DPZ IL patch formulations performed excellent skin permeability compared to that of the DPZ free-base patch in both in vitro and ex vivo skin permeability studies.

Canine Epidermal Keratinocytes (CPEK) Grown in Monolayer Are Not Representative of Normal Canine Keratinocytes for Permeability Studies: Pilot Studies

Canine progenitor epidermal keratinocytes (CPEK) are used as canine keratinocyte cell line. Their suitability for skin barrier studies is unknown. Measurement of transepithelial electric resistance (TEER) evaluates epithelial permeability. We compared TEER and tight junction (TJ) expression in CPEKs and normal keratinocytes (NK) harvested from biopsies of normal dogs. CPEKs and NK were grown until confluence (D0) and for 13 additional days. Slides were fixed on D0 and stained with ZO-1 and claudin-1 antibodies. Five images/antibody were taken, randomized and evaluated blindly by three investigators for intensity, staining location, granularity, and continuousness. Cell size and variability were evaluated. TEER increased overtime to 2000 Ohms/cm in NK, while remained around 100–150 Ohms/cm in CPEK. ANOVA showed significant effect of time (p < 0.0001), group (p < 0.0001) and group x time interaction (p < 0.0001) for TEER. Size of CPEKs was significantly (p < 0.0001) smaller and less variable (p = 0.0078) than NK. Intensity of claudin-1 staining was greater in CPEKs (p < 0.0001) while granularity was less in CPEKs (p = 0.0012). For ZO-1, cytoplasmic staining was greater in CPEK (p < 0.0001) while membrane continuousness of staining was greater in NK (p = 0.0002). We conclude that CPEKs grown in monolayer are not representative of NK for permeability studies.

Permeability Enhancement of Methotrexate Transdermal Gel using Eucalyptus oil, Peppermint Oil and Olive Oil(Conference Paper )#

Objective: the idea of this study to improve transdermal permeability of Methotrexate using eucalyptus oil, olive oil and peppermint oil as enhancers.Method: eucalyptus oil (2% and 4%), peppermint oil (2% and 4%) and olive oil (2% and 4%) all used as natural enhancers to develop transdermal permeability of Methotrexate via gel formulation. The gel was subjected to many physiochemical properties tests. In-vitro release and permeability studies for the drug were done by Franz cell diffusion across synthetic membrane, kinetic model was studied via korsmeyer- peppas equation.Result: the results demonstrate that safe, nonirritant or cause necrosis to rats' skin and stable till 60 days gel was successfully formulated.Methotrexate penetration alone without enhancer is only about 20%, while using enhancers reach to 85%, 99% and 90% with eucalyptus oil 4%, peppermint oil 4% and olive oil 4% respectively after 24 hours.Conclusion: Methotrexate transdermal gel was prepared and evaluated fruitfully in-vitro with a good permeation across semipermeable membrane. The results indicated that using of peppermint oil as enhancer have superiority to enhance the transdermal permeation of the Methotrexate.

Nanostructured Lipid Carriers Can Enhance Oral Absorption of Khellin, a Natural Pleiotropic Molecule

A novel formulation based on nanostructured lipid carriers (NLCs) was developed to increase solubility and intestinal absorption of khellin. K-NLCs were prepared with stearic acid, hempseed oil, Brij S20, and Labrafil M 1944 CS, using the emulsification-ultrasonication method. Developed nanoparticles were chemically and physically characterized by liquid chromatography, light scattering techniques, and electron microscopy. The size, about 200 nm, was optimal for oral delivery, and the polydispersity index (around 0.26), indicated high sample homogeneity. Additionally, K-NLCs showed a spherical morphology without aggregation by microscopic analysis. The encapsulation efficiency of khellin was about 55%. In vitro release studies were carried out in media with different pH to mimic physiological conditions. K-NLCs were found to be physically stable in the simulated gastric and intestinal fluids, and they preserved about 70% of khellin after 6 h incubation. K-NLCs were also successfully lyophilized testing different lyoprotectants, and obtained freeze-dried K-NLCs demonstrated good shelf life over a month. Lastly, permeability studies on Caco-2 cells were performed to predict khellin passive diffusion across the intestinal epithelium, demonstrating that nanoparticles increased khellin permeability by more than two orders of magnitude. Accordingly, developed NLCs loaded with khellin represent a versatile formulation with good biopharmaceutical properties for oral administration, possibly enhancing khellin’s bioavailability and therapeutic effects.

FORMULATION AND EVALUATION OF HERBAL ORAL EMULGEL CONTAINING PSIDIUM GUAJAVA LINN. LEAVES EXTRACT (A PREVENTIVE ORAL CARE PREPARATION)

Objective: The present research work is based to establish the formulation and evaluation of herbal oral emulgel containing extracts of powdered Psidium guajava Linn. leaves extract. Methods: The guava leaves were collected and extracted by cold maceration process using different solvents, further ethanolic extract was used for the emulgel preparation. Emulsion and gel phase were prepared separately and mixed together in ratio of 1:1. Results: Different formulations ere developed and evaluated for the physical appearance, pH, homogeneity, spreadability, viscosity, extrudability, antibacterial activity, and in vitro skin permeability studies. In all formulated emulgel containing P. guajava Linn. Leaves, extract F2 formulation gives all satisfactory results as in discuss in this paper. Conclusion: Overall, concluded that the extract might contain anti-bacterial properties and further tests are required to prove for oral care activity using other in vivo or in vitro techniques.

A Quasi-Physiological Microfluidic Blood-Brain Barrier Model for Brain Permeability Studies

Microfluidics-based organ-on-a-chip technology allows for developing a new class of in-vitro blood-brain barrier (BBB) models that recapitulate many hemodynamic and architectural features of the brain microvasculature not attainable with conventional two-dimensional platforms. Herein, we describe and validate a novel microfluidic BBB model that closely mimics the one in situ. Induced pluripotent stem cell (iPSC)-derived brain microvascular endothelial cells (BMECs) were juxtaposed with primary human pericytes and astrocytes in a co-culture to enable BBB-specific characteristics, such as low paracellular permeability, efflux activity, and osmotic responses. The permeability coefficients of [13C12] sucrose and [13C6] mannitol were assessed using a highly sensitive LC-MS/MS procedure. The resulting BBB displayed continuous tight-junction patterns, low permeability to mannitol and sucrose, and quasi-physiological responses to hyperosmolar opening and p-glycoprotein inhibitor treatment, as demonstrated by decreased BBB integrity and increased permeability of rhodamine 123, respectively. Astrocytes and pericytes on the abluminal side of the vascular channel provided the environmental cues necessary to form a tight barrier and extend the model’s long-term viability for time-course studies. In conclusion, our novel multi-culture microfluidic platform showcased the ability to replicate a quasi-physiological brain microvascular, thus enabling the development of a highly predictive and translationally relevant BBB model.

Revisão por décadas da evolução dos experimentos com o uso de condicionamento ácido sobre o complexo dentino-pulpar

The purpose of this review was to get significant experimental data about the acid etching technique upon the pulpo-dentinal complex highlighting aspects such as pulpal biology and dentinal permeability. Studies since the early 70's, going to 80's and 90's show the value of acid retention as well as the need of protective bases to lower the toxic effects of acid etching.

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.

Lanolin-Based Synthetic Membranes for Transdermal Permeation and Penetration Drug Delivery Assays

Due to the high similarity in composition and structure between lanolin and human SC lipids, we will work with two models from wool wax. Two types of lanolin were evaluated: one extracted with water and surfactants (WEL) and the other extracted with organic solvents (SEL). Skin permeation and skin penetration studies were performed with two active compounds to study the feasibility of the use of lanolin-based synthetic membranes as models of mammalian skin. Diclofenac sodium and lidocaine were selected as the active compounds considering that they have different chemical natures and different lipophilicities. In the permeation assay with SEL, a better correlation was obtained with the less permeable compound diclofenac sodium. This assay suggests the feasibility of using artificial membranes with SEL as a model for percutaneous absorption studies, even though the lipophilic barrier should be improved. Penetration profiles of the APIs through the SEL and WEL membranes indicated that the two membranes diminish penetration and can be considered good membrane surrogates for skin permeability studies. However, the WEL membranes, with a pH value similar to that of the skin surface, promoted a higher degree of diminution of the permeability of the two drugs, similar to those found for the skin.