Formulation Strategies to Improve Nose-to-Brain Delivery of Donepezil

Donepezil (DPZ) is widely used in the treatment of Alzheimer’s disease in tablet form for oral administration. The pharmacological efficacy of this drug can be enhanced by the use of intranasal administration because this route makes bypassing the blood–brain barrier (BBB) possible. The aim of this study was to develop a nanoemulsion (NE) as well as a nanoemulsion with a combination of bioadhesion and penetration enhancing properties (PNE) in order to facilitate the transport of DPZ from nose-to-brain. Composition of NE was established using three pseudo-ternary diagrams and PNE was developed by incorporating Pluronic F-127 to the aqueous phase. Parameters such as physical properties, stability, in vitro release profile, and ex vivo permeation were determined for both formulations. The tolerability was evaluated by in vitro and in vivo models. DPZ-NE and DPZ-PNE were transparent, monophasic, homogeneous, and physically stable with droplets of nanometric size and spherical shape. DPZ-NE showed Newtonian behavior whereas a shear thinning (pseudoplastic) behavior was observed for DPZ-PNE. The release profile of both formulations followed a hyperbolic kinetic. The permeation and prediction parameters were significantly higher for DPZ-PNE, suggesting the use of polymers to be an effective strategy to improve the bioadhesion and penetration of the drug through nasal mucosa, which consequently increase its bioavailability.This research was funded by the Secretaría de Educación Superior, Ciencia, Tecnología e Innovación (SENESCYT—Ecuador)

Estrategias terapéuticas basadas en micro y nanoemulsiones para el tratamiento del Alzheimer y enfermedades inflamatorias de la piel

[eng] Donepezil (DPZ) is one of the most widely prescribed drugs to treat the neuropsychiatric symptoms of Alzheimer's disease (AD) which are commercially available in oral tablet form. However, these can lead to inconveniences, especially among geriatric patients or those who are in advanced stages of the disease. In addition to this, there are marked disadvantages of the oral route, including difficulties in crossing the blood-brain barrier. The intranasal route presents an alternative due to its direct connection to the brain, which could increase the bioavailability of the drug. On the other hand, pioglitazone (PGZ) is a peroxisome proliferator-activated receptor γ (PPAR-γ) agonist used to treat type 2 diabetes mellitus. There is mounting scientific evidence of the anti-inflammatory effect of PGZ which suggests it as a promising candidate for the treatment of inflammatory disorders. The incorporation of these drugs in micro- and nanoemulsions could be used as a strategy to facilitate their administration. Based on these findings, the aim of this thesis was to design, develop and characterize intranasal DPZ micro- and nanoemulsions for the treatment of AD, as well as topical PGZ nanoemulsions for the treatment of inflammatory skin diseases. Two PGZ nanoemulsions (PGZ-NE and PGZ-NE2) along with one microemulsion and two nanoemulsions of DPZ (DPZ-ME, DPZ-NE, and DPZ-PNE) were formulated by constructing pseudo-ternary phase diagrams. All formulations were physically stable with spherical nanodroplets distributed uniformly in the system. The rheological analysis confirmed the Newtonian behavior in four formulations, while DPZ-PNE presented a pseudoplastic behavior. The five formulations were able to release the drug following a hyperbolic kinetic model. DPZ exhibited greater permeation through the porcine nasal mucosa from microemulsion compared to nanoemulsions, possibly due to its higher content of surfactants and cosurfactants. PGZ-NE and PGZ-NE2 favored the passage of the drug through the stratum corneum and promoted its retention in the skin thereby guaranteeing a local effect, especially for PGZ-NE2. The tolerance results demonstrated the biocompatibility and suitability of the formulations for intranasal or dermal administration. Finally, PGZ-NE treatment inhibited approximately 44% of inflammation, significantly decreased the expression of proinflammatory cytokines IL-6, IL-1β, and TNF-α, and counteracted histopathological alterations in acute inflammation assays, while PGZ-NE2 demonstrated efficacy in the treatment of atopic dermatitis, exhibiting reduction of skin lesions, restoration of elasticity and biomechanical properties of the skin, as well as reduction in the expression of proinflammatory cytokines associated with the pathophysiology of the disease. In conclusion, the obtained results encourage further clinical research into new therapeutic indications for PGZ as well as the use of intranasal-administered DPZ micro- and nanoemulsions to increase the bioavailability of the drug in the brain and facilitate its administration

Comparative study of ex vivo transmucosal permeation of Pioglitazone nanoparticles for the treatment of Alzheimer's disease

Pioglitazone has been reported in the literature to have a substantial role in the improvement of overall cognition in a mouse model. With this in mind, the aim of this study was to determine the most efficacious route for the administration of Pioglitazone nanoparticles (PGZ-NPs) in order to promote drug delivery to the brain for the treatment of Alzheimer's disease. PGZ-loaded NPs were developed by the solvent displacement method. Parameters such as mean size, polydispersity index, zeta potential, encapsulation efficacy, rheological behavior, and short-term stability were evaluated. Ex vivo permeation studies were then carried out using buccal, sublingual, nasal, and intestinal mucosa. PGZ-NPs with a size around of 160 nm showed high permeability in all mucosae. However, the permeation and prediction parameters revealed that lag-time and vehicle/tissue partition coefficient of nasal mucosa were significantly lower than other studied mucosae, while the diffusion coefficient and theoretical steady-state plasma concentration of the drug were higher, providing biopharmaceutical results that reveal more favorable PGZ permeation through the nasal mucosa. The results suggest that nasal mucosa represents an attractive and non-invasive pathway for PGZ-NPs administration to the brain since the drug permeation was demonstrated to be more favorable in this tissue. View Full-Text Keywords: nanoparticles; pioglitazone; PLGA-PEG; transmucosal permeations; Alzheimer's diseas

Effect of Penetration Enhancers and Safety on the Transdermal Delivery of Apremilast in Skin

The poor water solubility of apremilast (APR) is the main impediment to the penetration of the drug through the skin barrier. The objective of this study was to evaluate the permeability of APR in different solutions enriched with penetration promoters in ex vivo samples of human skin, and additionally assess its tolerance in vivo. To this end, APR solutions with 5% promoter were developed, and the drug's ability to penetrate human abdominal skin samples was evaluated; the coefficients of permeability, cumulated amounts permeated, and flow were some of the parameters evaluated; likewise, the in vitro and in vivo tolerance of the solutions was evaluated. The results obtained showed that the solutions containing squalene as a promoter improved the penetration of APR compared to the other promoters evaluated; in the same way, on an in vitro scale in HaCaT cells, the promoters were not toxic, finding a cell viability greater than 80% at the different dilutions evaluated. In the in vivo tests carried out with the solution that presented the best results (APRSqualene solution), it was observed that it does not cause irritation or erythema on the skin after its colorimetric and histological evaluation of the dorsal region of rats after its application. Squalene becomes an excellent candidate to improve the permeability of the drug in the case of the development of a topical formulation; in addition, it was confirmed that this penetration enhancer is neither toxic nor irritating when in contact with the skin in in vivo tests

Formulation Strategies to Improve Nose-to-Brain Delivery of Donepezil

Donepezil (DPZ) is widely used in the treatment of Alzheimer's disease in tablet form for oral administration. The pharmacological efficacy of this drug can be enhanced by the use of intranasal administration because this route makes bypassing the blood-brain barrier (BBB) possible. The aim of this study was to develop a nanoemulsion (NE) as well as a nanoemulsion with a combination of bioadhesion and penetration enhancing properties (PNE) in order to facilitate the transport of DPZ from nose-to-brain. Composition of NE was established using three pseudo-ternary diagrams and PNE was developed by incorporating Pluronic F-127 to the aqueous phase. Parameters such as physical properties, stability, in vitro release profile, and ex vivo permeation were determined for both formulations. The tolerability was evaluated by in vitro and in vivo models. DPZ-NE and DPZ-PNE were transparent, monophasic, homogeneous, and physically stable with droplets of nanometric size and spherical shape. DPZ-NE showed Newtonian behavior whereas a shear thinning (pseudoplastic) behavior was observed for DPZ-PNE. The release profile of both formulations followed a hyperbolic kinetic. The permeation and prediction parameters were significantly higher for DPZ-PNE, suggesting the use of polymers to be an effective strategy to improve the bioadhesion and penetration of the drug through nasal mucosa, which consequently increase its bioavailability

Characterization and In Vivo Anti-Inflammatory Efficacy of Copal (Dacryodes peruviana (Loes.) H.J. Lam) Essential Oil

Essential oils are natural aromatic substances that contain complex mixtures of many volatile compounds frequently used in pharmaceutical and cosmetic industries. Dacryodes peruviana (Loes.) H.J. Lam is a native species from Ecuador whose anti-inflammatory activity has not been previously reported, thus the aim of this study was to evaluate the anti-inflammatory activity of D. peruviana essential oil. To that end, essential oil from D. peruviana fruits was isolated by hydrodistillation and characterized physically and chemically. The tolerance of the essential oil was analyzed by cytotoxicity studies using human keratinocytes. The anti-inflammatory activity was evaluated by an arachidonic acid-induced edema model in mouse ear. The predominant compounds in D. peruviana essential oil were α-phellandrene, limonene, and α-pinene, with the three compounds reaching approximately 83% of the total composition. Tolerance studies showed high biocompatibility of this essential oil with human keratinocytes. In vivo studies demonstrated a moisturizing effect and an alleviation of several events occurred during the inflammatory process after topical treatment with D. peruviana essential oil such as decline in skin edema; reduction in leukocytic infiltrate; and decrease in inflammatory cytokines TNFα, IL-8, IL-17A, and IL-23. Therefore, this essential oil could be an attractive treatment for skin inflammation

Topical Pioglitazone Nanoformulation for the Treatment of Atopic Dermatitis: Design, Characterization and E cacy in Hairless Mouse Model

Pioglitazone (PGZ) is a drug used to treat type 2 diabetes mellitus that has been reported to show additional therapeutic activities on diverse inflammatory parameters. The aim of this study was to optimize a topical PGZ-loaded nanoemulsion (PGZ-NE) in order to evaluate its effectiveness for treating atopic dermatitis (AD). The composition of the nanoformulation was established by pseudo-ternary diagram. Parameters such as physical properties, stability, in vitro release profile, and ex vivo permeation were determined. The efficacy study was carried out using oxazolone-induced AD model in hairless mice. PGZ-NE released the drug following a hyperbolic kinetic. Additionally, its properties provided high retention potential of drug inside the skin. Therapeutic benefits of PGZ-NE were confirmed on diverse events of the inflammatory process, such as reduction of lesions, enhancement of skin barrier function, diminished infiltration of inflammatory cells, and expression of pro-inflammatory cytokines. These results were reinforced by atomic force microscope (AFM), which demonstrated the ability of the formulation to revert the rigidification caused by oxazolone and consequently improve the elasticity of the skin. These results suggest that PGZ-NE may be a promising treatment for inflammatory dermatological conditions such as AD.This work was supported by Secretaría de Educación Superior, Ciencia, Tecnología e Innovación (SENESCYT—Ecuador) (grant number 073-CIBAE-2015)

Quality by Design of Pranoprofen Loaded Nanostructured Lipid Carriers and Their Ex Vivo Evaluation in Different Mucosae and Ocular Tissues

Transmucosal delivery is commonly used to prevent or treat local diseases. Pranoprofen is an anti-inflammatory drug prescribed in postoperative cataract surgery, intraocular lens implantation, chorioretinopathy, uveitis, age-related macular degeneration or cystoid macular edema. Pranoprofen can also be used for acute and chronic management of osteoarthritis and rheumatoid arthritis. Quality by Design (QbD) provides a systematic approach to drug development and maps the influence of the formulation components. The aim of this work was to develop and optimize a nanostructured lipid carrier by means of the QbD and factorial design suitable for the topical management of inflammatory processes on mucosal tissues. To this end, the nanoparticles loading pranoprofen were prepared by a high-pressure homogenization technique with Tween 80 as stabilizer and Lanette® 18 as the solid lipid. From, the factorial design results, the PF-NLCs-N6 formulation showed the most suitable characteristics, which was selected for further studies. The permeability capacity of pranoprofen loaded in the lipid-based nanoparticles was evaluated by ex vivo transmucosal permeation tests, including buccal, sublingual, nasal, vaginal, corneal and scleral mucosae. The results revealed high permeation and retention of pranoprofen in all the tissues tested. According to the predicted plasma concentration at the steady-state, no systemic effects would be expected, any neither were any signs of ocular irritancy observed from the optimized formulation when tested by the HET-CAM technique. Hence, the optimized formulation (PF-NLCs-N6) may offer a safe and attractive nanotechnological tool in topical treatment of local inflammation on mucosal diseases

Therapeutic applications of essential oils from native and cultivated ecuadorian plants: Cutaneous candidiasis and dermal anti-inflammatory activity

Abstract: Essential oils are a complex mixture of aromatic substances whose pharmacological actions, including antimicrobial, antioxidant, anticancer, and anti-inflammatory activities, have been widely reported. This study aimed to evaluate the anti-Candida and dermal anti-inflammatory activity of essential oils from native and cultivated Ecuadorian plants. Essential oils from Bursera graveolens, Dacryodes peruviana, Mespilodaphne quixos, and Melaleuca armillaris were isolated by hydrodistillation and were characterized physically and chemically. Its tolerance was analyzed by in vitro and in vivo studies. The antifungal activity was studied against Candida albicans, Candida glabrata, and Candida parapsilosis, whereas the anti-inflammatory effect was evaluated by a mouse ear edema model. The main compounds were limonene, -phellandrene, (E)-methyl cinnamate, and 1,8-cineole, respectively. All essential oils showed high tolerability for skin application, antifungal activity against the three Candida strains, and anti-inflammatory efficacy by decreasing edema and overexpression of pro-inflammatory cytokines. Dacryodes peruviana essential oil showed the highest antifungal activity. On the other hand, Dacryodes peruviana and Melaleuca armillaris showed the greatest anti-inflammatory potential, decreasing edema by 53.3% and 65.25%, respectively, and inhibiting the overexpression of TNF- , IL-8, IL-17A, and IL-23. The results suggest that these essential oils could be used as alternative therapies in the treatment of both cutaneous candidiasis and dermal inflammation

Therapeutic applications of essential oils from native and cultivated ecuadorian plants: Cutaneous candidiasis and dermal anti-inflammatory activity

Abstract: Essential oils are a complex mixture of aromatic substances whose pharmacological actions, including antimicrobial, antioxidant, anticancer, and anti-inflammatory activities, have been widely reported. This study aimed to evaluate the anti-Candida and dermal anti-inflammatory activity of essential oils from native and cultivated Ecuadorian plants. Essential oils from Bursera graveolens, Dacryodes peruviana, Mespilodaphne quixos, and Melaleuca armillaris were isolated by hydrodistillation and were characterized physically and chemically. Its tolerance was analyzed by in vitro and in vivo studies. The antifungal activity was studied against Candida albicans, Candida glabrata, and Candida parapsilosis, whereas the anti-inflammatory effect was evaluated by a mouse ear edema model. The main compounds were limonene, -phellandrene, (E)-methyl cinnamate, and 1,8-cineole, respectively. All essential oils showed high tolerability for skin application, antifungal activity against the three Candida strains, and anti-inflammatory efficacy by decreasing edema and overexpression of pro-inflammatory cytokines. Dacryodes peruviana essential oil showed the highest antifungal activity. On the other hand, Dacryodes peruviana and Melaleuca armillaris showed the greatest anti-inflammatory potential, decreasing edema by 53.3% and 65.25%, respectively, and inhibiting the overexpression of TNF- , IL-8, IL-17A, and IL-23. The results suggest that these essential oils could be used as alternative therapies in the treatment of both cutaneous candidiasis and dermal inflammation