Development of Apremilast formulations for the treatment of skin and mucous membrane pathologies

[spa] Apremilast (APR) es un inhibidor selectivo de la fosfodiesterasa 4 que se administra por vía oral para el tratamiento de la psoriasis en placas de moderada a grave y la artritis psoriásica activa. La baja solubilidad y permeabilidad de este fármaco dificultan su administración dérmica. Uno de los propósitos de este estudio fue diseñar y caracterizar una microemulsión cargada con apremilast como terapia tópica para la inflamación local de la piel. Su composición se determinó mediante diagramas pseudoternarios. Se realizaron caracterizaciones físicas, químicas y biofarmacéuticas. Se estudió la estabilidad de esta formulación durante 90 días. Se evaluó la tolerabilidad de APR-ME en voluntarios sanos y se estudió su potencial antiinflamatorio mediante modelos in vitro e in vivo. Se obtuvo una formulación homogénea con comportamiento newtoniano y gotas de tamaño nanométrico y forma esférica. APR-ME liberó el fármaco incorporado siguiendo una cinética de primer orden y facilitó la retención del fármaco en la piel, asegurando un efecto local. Se observó potencial antiinflamatorio por su capacidad para disminuir la producción de IL-6 e IL-8 en el modelo in vitro. Este efecto se confirmó en el modelo in vivo histológicamente por la reducción de la infiltración de células inflamatorias e inmunológicamente por la disminución de las citocinas inflamatorias IL-8, IL-17A y TNFα. En consecuencia, estos resultados sugieren que esta formulación podría utilizarse como un atractivo tratamiento tópico para la inflamación cutánea. Por otro lado, la escasa solubilidad en agua de APR es el principal impedimento para la penetración del fármaco a través de la barrera cutánea. Otro de los objetivos del estudio era evaluar la permeabilidad de APR en diferentes soluciones enriquecidas con promotores de la penetración en muestras ex vivo de piel humana, y evaluar además su tolerancia in vivo. Para ello, se desarrollaron soluciones de APR con un 5% de promotor y se evaluó la capacidad del fármaco para penetrar en muestras de piel abdominal humana; los coeficientes de permeabilidad, las cantidades acumuladas permeadas y el flujo fueron algunos de los parámetros evaluados. Asimismo, se evaluó la tolerancia in vitro e in vivo de las soluciones. Los resultados obtenidos mostraron que las soluciones que contenían escualeno como promotor mejoraban la penetración de la APR en comparación con los otros promotores evaluados; del mismo modo, a escala in vitro en células HaCaT los promotores no resultaron tóxicos, encontrándose una viabilidad celular superior al 80% en las diferentes diluciones evaluadas. En las pruebas in vivo realizadas con APR-Escualeno presentó los mejores resultados. El escualeno se convierte en un excelente candidato para mejorar la permeabilidad del fármaco en el caso del desarrollo de una formulación tópica; además, se confirmó que este potenciador de la penetración no es ni tóxico ni irritante en contacto con la piel en ensayos in vivo.[eng] Apremilast (APR) is a selective phosphodiesterase-4 inhibitor that is administered orally for the treatment of moderate to severe plaque psoriasis and active psoriatic arthritis. The low solubility and permeability of this drug make dermal administration difficult. One of the purposes of this study was to design and characterize an apremilast-loaded microemulsion as a topical therapy for local skin inflammation. Its composition was determined using pseudoternary diagrams. Physical, chemical and biopharmaceutical characterizations were performed. The stability of this formulation was studied for 90 days. The tolerability of APR-ME was evaluated in healthy volunteers and its anti- inflammatory potential was studied by in vitro and in vivo models. A homogeneous formulation with Newtonian behavior and droplets of nanometer size and spherical shape was obtained. APR-ME released the incorporated drug following first-order kinetics and facilitated drug retention in the skin, ensuring a local effect. Anti-inflammatory potential was observed due to its ability to decrease IL-6 and IL-8 production in the in vitro model. This effect was confirmed in the in vivo model histologically by the reduction of inflammatory cell infiltration and immunologically by the decrease of inflammatory cytokines IL- 8, IL-17A and TNFα. Consequently, these results suggest that this formulation could be used as an attractive topical treatment for cutaneous inflammation. On the other hand, the poor water solubility of APR is the main impediment to the penetration of the drug through the skin barrier. Another objective of the study was to evaluate the permeability of APR in different solutions enriched with penetration promoters in ex vivo samples of human skin, and also to evaluate its in vivo tolerance. For this purpose, APR solutions with 5% promoter were developed and the ability of the drug to penetrate human abdominal skin samples was evaluated; permeability coefficients, permeated cumulative amounts and flux were some of the parameters evaluated. The in vitro and in vivo tolerance of the solutions was also evaluated. The results obtained showed that the solutions containing squalene as promoter improved the penetration of APR compared to the other promoters evaluated; likewise, at in vitro scale in HaCaT cells the promoters were not toxic, finding a cell viability higher than 80% in the different dilutions evaluated. In the in vivo tests carried out with APR-Squalene, it presented the best results. Squalene becomes an excellent candidate to improve drug permeability in the case of the development of a topical formulation; in addition, it was confirmed that this penetration enhancer is neither toxic nor irritating in contact with the skin in vivo tests

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

Apremilast Microemulsion as Topical Therapy for Local Inflammation: Design, Characterization and Efficacy Evaluation

Apremilast (APR) is a selective phosphodiesterase 4 inhibitor administered orally in the treatment of moderate-to-severe plaque psoriasis and active psoriatic arthritis. The low solubility and permeability of this drug hinder its dermal administration. The purpose of this study was to design and characterize an apremilast-loaded microemulsion (APR-ME) as topical therapy for local skin inflammation. Its composition was determined using pseudo-ternary diagrams. Physical, chemical and biopharmaceutical characterization were performed. Stability of this formulation was studied during 90 days. Tolerability of APR-ME was evaluated in healthy volunteers while its anti-inflammatory potential was studied using in vitro and in vivo models. A homogeneous formulation with Newtonian behavior and droplets of nanometric size and spherical shape was obtained. APR-ME released the incorporated drug following a first-order kinetic and facilitated drug retention into the skin, ensuring a local effect. Anti-inflammatory potential was observed for its ability to decrease the production of IL-6 and IL-8 in the in vitro model. This effect was confirmed in the in vivo model histologically by reduction in infiltration of inflammatory cells and immunologically by decrease of inflammatory cytokines IL-8, IL-17A and TNFα. Consequently, these results suggest that this formulation could be used as an attractive topical treatment for skin inflammation

Apremilast Microemulsion as Topical Therapy for Local Inflammation: Design, Characterization and Efficacy Evaluation

Apremilast (APR) is a selective phosphodiesterase 4 inhibitor administered orally in the treatment of moderate-to-severe plaque psoriasis and active psoriatic arthritis. The low solubility and permeability of this drug hinder its dermal administration. The purpose of this study was to design and characterize an apremilast-loaded microemulsion (APR-ME) as topical therapy for local skin inflammation. Its composition was determined using pseudo-ternary diagrams. Physical, chemical and biopharmaceutical characterization were performed. Stability of this formulation was studied for 90 days. Tolerability of APR-ME was evaluated in healthy volunteers while its anti-inflammatory potential was studied using in vitro and in vivo models. A homogeneous formulation with Newtonian behavior and droplets of nanometric size and spherical shape was obtained. APR-ME released the incorporated drug following a first-order kinetic and facilitated drug retention into the skin, ensuring a local effect. Anti-inflammatory potential was observed for its ability to decrease the production of IL-6 and IL-8 in the in vitro model. This effect was confirmed in the in vivo model histologically by reduction in infiltration of inflammatory cells and immunologically by decrease of inflammatory cytokines IL-8, IL-17A and TNFα. Consequently, these results suggest that this formulation could be used as an attractive topical treatment for skin inflammation

Desarrollo de formulaciones de Apremilast para el tratamiento de patologías en piel y mucosas = Development of Apremilast formulations for the treatment of skin and mucous membrane pathologies

Programa de Doctorat en Recerca, Desenvolupament i Control de Medicaments[spa] Apremilast (APR) es un inhibidor selectivo de la fosfodiesterasa 4 que se administra por vía oral para el tratamiento de la psoriasis en placas de moderada a grave y la artritis psoriásica activa. La baja solubilidad y permeabilidad de este fármaco dificultan su administración dérmica. Uno de los propósitos de este estudio fue diseñar y caracterizar una microemulsión cargada con apremilast como terapia tópica para la inflamación local de la piel. Su composición se determinó mediante diagramas pseudoternarios. Se realizaron caracterizaciones físicas, químicas y biofarmacéuticas. Se estudió la estabilidad de esta formulación durante 90 días. Se evaluó la tolerabilidad de APR-ME en voluntarios sanos y se estudió su potencial antiinflamatorio mediante modelos in vitro e in vivo. Se obtuvo una formulación homogénea con comportamiento newtoniano y gotas de tamaño nanométrico y forma esférica. APR-ME liberó el fármaco incorporado siguiendo una cinética de primer orden y facilitó la retención del fármaco en la piel, asegurando un efecto local. Se observó potencial antiinflamatorio por su capacidad para disminuir la producción de IL-6 e IL-8 en el modelo in vitro. Este efecto se confirmó en el modelo in vivo histológicamente por la reducción de la infiltración de células inflamatorias e inmunológicamente por la disminución de las citocinas inflamatorias IL-8, IL-17A y TNFα. En consecuencia, estos resultados sugieren que esta formulación podría utilizarse como un atractivo tratamiento tópico para la inflamación cutánea. Por otro lado, la escasa solubilidad en agua de APR es el principal impedimento para la penetración del fármaco a través de la barrera cutánea. Otro de los objetivos del estudio era evaluar la permeabilidad de APR en diferentes soluciones enriquecidas con promotores de la penetración en muestras ex vivo de piel humana, y evaluar además su tolerancia in vivo. Para ello, se desarrollaron soluciones de APR con un 5% de promotor y se evaluó la capacidad del fármaco para penetrar en muestras de piel abdominal humana; los coeficientes de permeabilidad, las cantidades acumuladas permeadas y el flujo fueron algunos de los parámetros evaluados. Asimismo, se evaluó la tolerancia in vitro e in vivo de las soluciones. Los resultados obtenidos mostraron que las soluciones que contenían escualeno como promotor mejoraban la penetración de la APR en comparación con los otros promotores evaluados; del mismo modo, a escala in vitro en células HaCaT los promotores no resultaron tóxicos, encontrándose una viabilidad celular superior al 80% en las diferentes diluciones evaluadas. En las pruebas in vivo realizadas con APR-Escualeno presentó los mejores resultados. El escualeno se convierte en un excelente candidato para mejorar la permeabilidad del fármaco en el caso del desarrollo de una formulación tópica; además, se confirmó que este potenciador de la penetración no es ni tóxico ni irritante en contacto con la piel en ensayos in vivo.[eng] Apremilast (APR) is a selective phosphodiesterase-4 inhibitor that is administered orally for the treatment of moderate to severe plaque psoriasis and active psoriatic arthritis. The low solubility and permeability of this drug make dermal administration difficult. One of the purposes of this study was to design and characterize an apremilast-loaded microemulsion as a topical therapy for local skin inflammation. Its composition was determined using pseudoternary diagrams. Physical, chemical and biopharmaceutical characterizations were performed. The stability of this formulation was studied for 90 days. The tolerability of APR-ME was evaluated in healthy volunteers and its anti- inflammatory potential was studied by in vitro and in vivo models. A homogeneous formulation with Newtonian behavior and droplets of nanometer size and spherical shape was obtained. APR-ME released the incorporated drug following first-order kinetics and facilitated drug retention in the skin, ensuring a local effect. Anti-inflammatory potential was observed due to its ability to decrease IL-6 and IL-8 production in the in vitro model. This effect was confirmed in the in vivo model histologically by the reduction of inflammatory cell infiltration and immunologically by the decrease of inflammatory cytokines IL- 8, IL-17A and TNFα. Consequently, these results suggest that this formulation could be used as an attractive topical treatment for cutaneous inflammation. On the other hand, the poor water solubility of APR is the main impediment to the penetration of the drug through the skin barrier. Another objective of the study was to evaluate the permeability of APR in different solutions enriched with penetration promoters in ex vivo samples of human skin, and also to evaluate its in vivo tolerance. For this purpose, APR solutions with 5% promoter were developed and the ability of the drug to penetrate human abdominal skin samples was evaluated; permeability coefficients, permeated cumulative amounts and flux were some of the parameters evaluated. The in vitro and in vivo tolerance of the solutions was also evaluated. The results obtained showed that the solutions containing squalene as promoter improved the penetration of APR compared to the other promoters evaluated; likewise, at in vitro scale in HaCaT cells the promoters were not toxic, finding a cell viability higher than 80% in the different dilutions evaluated. In the in vivo tests carried out with APR-Squalene, it presented the best results. Squalene becomes an excellent candidate to improve drug permeability in the case of the development of a topical formulation; in addition, it was confirmed that this penetration enhancer is neither toxic nor irritating in contact with the skin in vivo tests

Galenic and Biopharmaceutical Study of the Triamcinolone Acetonide and Lidocaine Hydrochloride Semisolid Formulations for Buccal Administration

The mouth can be affected by important inflammatory processes resulting from localized or systemic diseases, such as diabetes, AIDS, and leukemia, among others, which are manifested in various types of buccal sores, typically presenting pain [1]. The present work focuses on the design, formulation, and characterization of four semi-solid formulations for oral mucosa in order to symptomatically treat these painful processes. The formulations have two active pharmaceutical ingredients: triamcinolone acetonide (TA) and lidocaine hydrochloride (LIDO). The formulations also contain Orabase® as an excipient, which is a protective, hydrophobic, and anhydrous adhesive vehicle, used to retain or facilitate the application of active pharmaceutical ingredients (APIs) to the oral mucosa. After designing the formulations, the validation of the analytical method was performed to achieve reliable analytical results. Franz-type diffusion cells were used to perform drug release studies using synthetic membrane, and permeation studies using buccal mucosa, permitting the estimation of the amount and rate of TA permeated across this mucous membrane. Further, the amount of TA retained within the tissue was estimated, as this is where it performs its anti-inflammatory activity, and showed no significant differences between the 0.05% TA + LIDO and 0.1% TA + LIDO formulations (p > 0.05). Therefore, the results demonstrate the suitability of the administration of the lowest concentration of TA tested, which achieved a similar efficacy as higher concentrations and reduced the potential systemic effects of corticoid administration. Furthermore, sublingual permeation studies were carried out to evaluate a scenario of continuous contact of the tongue with the applied formulation. The four formulations studied show pseudoplastic and thixotropic behavior, ideal for topical application. These results provide evidence for the potential of these topical formulations for the treatment of inflammatory processes in the buccal mucosa. Keywords: triamcinolone acetonide; buccal administration; semisolid formulations; thixotropic behavior; lidocaine hydrochloride; Franz-type diffusion cell

Biopharmaceutical Study of Triamcinolone Acetonide Semisolid Formulations for Sublingual and Buccal Administration

The mouth can be affected by important inflammatory processes resulting from localized or systemic diseases such as diabetes, AIDS and leukemia, among others, and are manifested in various types of buccal sores typically presenting pain. This work focuses on the design, formulation, and characterization of four semisolid formulations for oral mucosa in order to symptomatically treat these painful processes. The formulations have two active pharmaceutical ingredients, triamcinolone acetonide (TA) and lidocaine hydrochloride (LIDO). The formula also contains, as an excipient, Orabase®, which is a protective, hydrophobic, and anhydrous adhesive vehicle, used to retain or facilitate the application of active pharmaceutical ingredients to the oral mucosa. After designing the formulations, an analytical method for TA was validated using HPLC so as to achieve reliable analytical results. Franz-type diffusion cells were used to perform drug release studies using synthetic membrane, and permeation studies using buccal mucosa, estimating the amount and rate of TA permeated across the tissue. Additionally, sublingual permeation studies were carried out to evaluate a scenario of a continuous contact of the tongue with the applied formulation. Permeation fluxes and the amount of TA retained within sublingual mucosa were similar to those in buccal mucosa, also implying anti-inflammatory activity in the part of the tongue that is in direct contact with the formulation. In addition, the dynamic conditions of the mouth were recreated in terms of the presence of phosphate buffered saline, constant movement of the tongue, pH, and temperature, using dissolution equipment. The amount of TA released into the phosphate buffered saline in dynamic conditions (subject to being ingested) is well below the normal oral doses of TA, for which the formulation can be considered safe. The formulations applied to buccal or sublingual mucosas under dynamic conditions permit the successful retention of TA within either tissue, where it exerts anti-inflammatory activity. The four formulations studied show a pseudoplastic and thixotropic behavior, ideal for topical application. These results evidence the potential of these topical formulations in the treatment of inflammatory processes in the buccal mucosa