Evaluation of Silybin Nanoparticles against Liver Damage in Murine Schistosomiasis mansoni Infection.

Silybin (SIB) is a hepatoprotective drug known for its poor oral bioavailability, attributed to its classification as a class IV drug with significant metabolism during the first-pass effect. This study explored the potential of solid lipid nanoparticles with (SLN-SIB-U) or without (SLN-SIB) ursodeoxycholic acid and polymeric nanoparticles (PN-SIB) as delivery systems for SIB. The efficacy of these nanosystems was assessed through in vitro studies using the GRX and Caco-2 cell lines for permeability and proliferation assays, respectively, as well as in vivo experiments employing a murine model of Schistosomiasis mansoni infection in BALB/c mice. The mean diameter and encapsulation efficiency of the nanosystems were as follows: SLN-SIB (252.8 ± 4.4 nm, 90.28 ± 2.2%), SLN-SIB-U (252.9 ± 14.4 nm, 77.05 ± 2.8%), and PN-SIB (241.8 ± 4.1 nm, 98.0 ± 0.2%). In the proliferation assay with the GRX cell line, SLN-SIB and SLN-SIB-U exhibited inhibitory effects of 43.09 ± 5.74% and 38.78 ± 3.78%, respectively, compared to PN-SIB, which showed no inhibitory effect. Moreover, SLN-SIB-U demonstrated a greater apparent permeability coefficient (25.82 ± 2.2) than PN-SIB (20.76 ± 0.1), which was twice as high as that of SLN-SIB (11.32 ± 4.6) and pure SIB (11.28 ± 0.2). These findings suggest that solid lipid nanosystems hold promise for further in vivo investigations. In the murine model of acute-phase Schistosomiasis mansoni infection, both SLN-SIB and SLN-SIB-U displayed hepatoprotective effects, as evidenced by lower alanine amino transferase values (22.89 ± 1.6 and 23.93 ± 2.4 U/L, respectively) than those in control groups I (29.55 ± 0.7 U/L) and I+SIB (34.29 ± 0.3 U/L). Among the prepared nanosystems, SLN-SIB-U emerges as a promising candidate for enhancing the pharmacokinetic properties of SIB.

In vitro transdermal drug permeation tests: a regulatory scenario evaluation

SUMMARY Introduction: The Transdermal Drug Delivery Systems (TDDS) could circumvent the inconveniences of oral administration, increasing treatment adhesion. Meanwhile, despite being highly widespread systems, there are discrepancies between the performance and quality control methodologies recommended by the leading regulatory agencies, which is an issue for the pharmaceutical industry. Aim: To identify and to compare the requirements for TDDS regulatory approval by important agencies, focusing on the in vitro release and drug permeation studies, which are crucial tests for the evaluation of safety, efficacy, and performance of these systems. Methods: The documents that regulate the scope of TDDS in FDA, EMA and Anvisa were analyze, as well as the contributions of OECD. In addition, an approaching regarding the pharmacopeial requirements was made regarding USA, Europe, and Brazil. Results and conclusion: Concerning the regulatory approval aspects, the FDA is reviewing its documents because the current guidance is not specific to transdermal systems. On the other hand, the EMA presents a unique guideline that includes specific requirements for TDDS. The USA and the European Pharmacopoeias have specific mentions to performance and quality control of TDDS, while the Brazilian Pharmacopoeia does not mention this dosage form. Recently, Anvisa published a guide, which helps Brazilian manufacturers concerning the tests required for the regulatory approval of a new TDDS. The launch of this standardized national statute associated with the use of a validated in vitro release and permeation tests represents a remarkable breakthrough regarding TDDS.

Introducción: los sistemas de administración de fármacos transdérmicos (TDDS) podrían sortear los inconvenientes de la administración por vía oral, aumentando la adherencia al tratamiento. Mientras tanto, a pesar de ser sistemas muy extendidos, existen discrepancias entre las metodologías de desempeño y control de calidad recomendadas por las principales agencias reguladoras, lo cual es un problema para la industria farmacéutica. Objetivo: identificar y comparar los requisitos para la aprobación regulatoria de TDDS por parte de las principales agencias reguladoras, enfocándose en los estudios de liberación in vitro y premiación de fármacos. Métodos: se analizaron los documentos que regulan el alcance de la TDDS en la FDA, EMA y Anvisa, así como los aportes de la OCDE. Además, se realizó un planteamiento sobre los requisitos de las farmacopeas de los Estados Unidos, Europa y Brasil. Resultados y conclusión: la FDA está revisando los aspectos de aprobación regulatoria porque la guía actual no es específica para los sistemas transdérmicos. Por otro lado, la EMA presenta una guía única que incluye requisitos específicos para TDDS. Las farmacopeas de los Estados Unidos e Europa tienen menciones específicas al rendimiento y control de calidad de TDDS, mientras que la Farmacopea brasileña no menciona esta forma de dosificación. Recientemente, Anvisa publicó una guía que ayuda a los fabricantes brasileños en cuanto a las pruebas requeridas para la aprobación regulatoria de un nuevo TDDS. El lanzamiento de este estatuto nacional estandarizado asociado con el uso de pruebas validadas de liberación y premiación in vitro representa un avance notable con respecto a TDDS.

Introdução: os sistemas de liberação transdérmica (SLT) são capazes de contornar as desvantagens da administração oral de medicamentos, aumentando a adesão ao tratamento. Entretanto, apesar de serem sistemas difundidos, existem discrepâncias entre as metodologias de desempenho e controle de qualidade recomendadas pelas agências regulatórias, dificultando o desenvolvimento destes pela indústria farmacêutica. Objetivo: identificar e comparar os requisitos para aprovação regulatória de SLT por importantes agências regulatórias, com foco nos estudos de liberação e permeação de fármacos in vitro, testes fundamentais para avaliação da segurança, eficácia e desempenho desses sistemas. Métodos: foram analisados os documentos que regulam o escopo dos SLT publicados pela FDA, EMA e Anvisa e as contribuições da OCDE. Além disso, foi realizada a abordagem sobre os requisitos farmacopeicos nos Estados Unidos, Europa e Brasil. Resultados e conclusão: FDA está revisando os aspectos de aprovação regulatória, pois os documentos atuais não são específicos para os SLT. Em contraponto, a EMA apresenta uma diretriz única que inclui requisitos específicos para estes sistemas. Em relação às farmacopeias, enquanto EUA e Europa apresentam recomendações específicas para desempenho e controle de qualidade dos SLT, a Farmacopeia brasileira não menciona esta forma farmacêutica. Recentemente, a Anvisa publicou um guia com os testes necessários para o registro destes sistemas. O lançamento de tal publicação, associado a ensaios devidamente validados representam um avanço notável no escopo regulatório dos SLT.

Nanoparticles Loaded with a New Thiourea Derivative: Development and In vitro Evaluation Against Leishmania amazonensis.

BACKGROUND: Leishmaniasis is a neglected tropical disease caused by protozoa of the genus Leishmania. Current treatments are restricted to a small number of drugs that display both severe side effects and a potential for parasites to develop resistance. A new N-(3,4-methylenedioxyphenyl)-N'- (2-phenethyl) thiourea compound (thiourea 1) has shown promising in vitro activity against Leishmania amazonensis with an IC50 of 54.14 µM for promastigotes and an IC50 of 70 µM for amastigotes. OBJECTIVE: To develop a formulation of thiourea 1 as an oral treatment for leishmaniasis, it was incorporated into Nanoparticles (NPs), a proven approach to provide long-acting drug delivery systems. METHODS: Poly (D,L-Lactic-co-Glycolic Acid) (PLGA) polymeric NPs containing thiourea 1 were obtained through a nanoprecipitation methodology associated with solvent evaporation. The NPs containing thiourea 1 were characterized for Encapsulation Efficiency (EE%), reaction yield (% w/w), surface charge, particle size and morphology by Transmission Electron Microscopy (TEM). RESULTS: NPs with thiourea 1 showed an improved in vitro leishmanicidal activity with a reduction in its cytotoxicity against macrophages (CC50>100 µg/mL) while preserving its IC50 against intracellular amastigotes (1.46 ± 0.09 µg/mL). This represents a parasite Selectivity Index (SI) of 68.49, which is a marked advancement from the reference drug pentamidine (SI = 30.14). CONCLUSION: The results suggest that the incorporation into NPs potentiated the therapeutic effect of thiourea 1, most likely by improving the selective delivery of the drug to the phagocytic cells that are targeted for infection by L. amazonensis. This work reinforces the importance of nanotechnology in the acquisition of new therapeutic alternatives for oral treatments.

Development of a doxazosin and finasteride transdermal system for combination therapy of benign prostatic hyperplasia.

The treatment of benign prostatic hyperplasia can be accomplished by the use of different drugs including, doxazosin, an α-1 adrenergic antagonist, and finasteride (FIN), a 5-α reductase inhibitor. Traditionally, treatments using these drugs have been administered as either a mono or combination therapy by the oral route. A transdermal delivery system optimized for doxazosin and FIN combination therapy would provide increased patient adherence and facilitate dose adjustment. Doxazosin base (DB) was prepared from doxazosin mesylate and characterized together with FIN, by X-ray powder diffraction (XRD), differential scanning calorimetry (DSC), and nuclear magnetic resonance (NMR). The permeation enhancers, azone and lauric acid, and the gelling agents, hydroxypropyl cellulose (HPC) and Poloxamer 407 (P407), were evaluated to determine their ability to promote in vitro permeation of drugs through the pig ear epidermis. Successful preparation of DB was confirmed by evaluating the XRD, DSC, and NMR patterns and in vitro studies revealed that 3% (w/w) azone was the best permeation enhancer. When P407 gel was compared with HPC gel, it showed reduced lag time and promoted higher permeation of both drugs. This may be because of the interactions of the former with the stratum corneum, which disorganizes the lipid structure and consequently promotes higher drug permeation.