Lipid core nanocapsules-loaded tacrolimus: Development and evaluation of quality parameters

This study aimed to revalidate an HPLC-based analytical methodology to determine  tacrolimus within lipid-core nanocapsules and to evaluate the quality of such nanosystems. Chromatographic separation was achieved by employing a C18 column as a stationary phase and a ternary mixture of acetonitrile: water: phosphoric acid (700:299:1 v/v) as the mobile phase. The revalidated method proved to be linear in the range of 1-60 µg.mL−1 for tacrolimus (r2 >0.999). Detection and quantification limits were 45.38 ng.mL-1 and 137.51 ng.mL-1, respectively, which assures the methodology sensitivity. The method was also precise (RSD = 1.78% between samples). Besides, the methodology demonstrated accuracy and robustness. The lipid-core nanocapsules-loaded tacrolimus showed exclusively nanosized particles (±190 nm and polydispersity index of ≤v0.2), negative zeta potential (-13.67±1.16), and slightly acidic pH (5.58 ± 0.06), with a content of 98.90±2.32%  and encapsulation rate of 99.23±0.32%.  Tacrolimus-loaded in lipid-core nanocapsules-loaded tacrolimus showed stability for at least 30 days at room temperature and a sustained release profile compared to the drug in solution

Desenvolvimento de nanocápsulas de núcleo lipídico contendo tacrolimus : validação de método analítico, avaliação da qualidade e do perfil de liberação sustentada

A psoríase é uma doença inflamatória crônica recorrente, caracterizada pelo surgimento de lesões e placas escamosas e eritematosas na pele. O seu tratamento consiste na remissão da doença, sendo a via tópica a mais indicada, uma vez que é de fácil administração e apresenta reduzidos efeitos colaterais, sendo um dos fármacos utilizados para esta via o tacrolimus (TAC). Este fármaco é um inibidor da calcineurina com atividade imunossupressora, com permeação limitada em regiões com placas hiperqueratósicas, devido às suas características fisico-químicas, como alta lipofilicidade. Nanocápsulas de núcleo lipídico (NC) podem ser uma alternativa na otimização dessas formulações tópicas por serem capazes de aumentar a solubilidade aparente de fármacos e promoverem a permeação dos fármacos e seu depósito no estrato córneo e epiderme, sem que haja absorção sistêmica. Assim, este trabalho visou a obtenção de uma formulação nanotecnológica com perfil de liberação sustentada contendo TAC incorporado a NC de poli(ε-caprolactona) Mn 80 kg.mol-1 (NC-TAC) para uma adequada entrega do fármaco através da via cutânea com vista a propor um novo tratamento para doenças autoimunes que acometem a pele. Para tanto, primeiramente foi revalidado a uma metodologia analítica simples e robusta para a identificação e quantificação de TAC de forma rápida e precisa ao longo dos experimentos, com vistas a atender as normas internacionais e a legislação nacional. Posteriormente, NC-TAC foram desenvolvidas pela técnica de nanoprecipitação e caracterizadas. Nossos achados mostraram que NC branca e NC-TAC apresentaram características nanométricas (195±4nm e 199±3nm respectivamente), pH (5.46 ±0.14 e 5.58± 0.06 respectivamente) levemente ácido, adequado para a via tópica e teor de fármaco e eficiência de encapsulação próximas a 100% para NC-TAC (0.08% TAC). Nossos resultados também indicam que NC-TAC apresenta estabilidade em condições ambiente ao longo de 30 dias. Além disso, esta formulação apresentou perfil de liberação biexponencial e liberação sustentada de TAC nas condições experimentais avaliadas. Portanto, a formulação nanotecnológica contendo TAC mostra-se promissora para a incorporação em formulações tópicas para o tratamento de doenças autoimunes que acomete a pele, como a psoríase.Psoriasis is a recurrent chronic inflammatory disease, characterized by the appearance of lesions, scaly and erythematous plaques on the skin. Its treatment consists of remission of the disease, the topical route being the most indicated, since it is easy to administer drugs and it has reduced side effects. In addition, there are off-label indications for the treatment of psoriasis by the topical route, one of which is the use of tacrolimus (TAC). It is a calcineurin inhibiting drug with immunosuppressive activity with limited permeation in regions with hyperkeratotic plaques, due to its physicochemical characteristics, such as high lipophilicity. Lipid core (NC) nanocapsules can be an alternative in the optimization of these topical formulations because they are able to increase the apparent solubility of drugs and promote the permeation of drugs and their deposition in the stratum corneum and epidermis, without systemic absorption. Thus, this work aimed at obtaining a nanotechnological formulation with a sustained release profile containing TAC incorporated in NC of poly (ε-caprolactone) Mn 80 kg.mol-1 (NC-TAC) for an adequate delivery of the drug through the cutaneous route with a view to proposing a new treatment for autoimmune diseases that affect the skin, such as psoriasis. To this end, a simple and robust analytical methodology was firstly developed and revalidated for the identification and quantification of TACs quickly and accurately throughout the experiments, with a view to meeting the international standards and the national legislation. Subsequently, NC-TAC formulations were developed by the technique of nanoprecipitation and characterized. Our findings showed that NC and NC-TAC had nanometric characteristics (195 ± 4nm and 199 ± 3nm respectively), pH (5.46 ± 0.14 and 5.58 ± 0.06 respectively) slightly acidic, suitable for the topical route and drug content and encapsulation efficiency close to 100% for NC-TAC. In addition, our results indicate that NC-TAC is stable over 30 days. Besides, this formulation presented a profile of biexponential release and sustained release of TAC under the evaluated experimental conditions. Therefore, the nanotechnological formulation containing TAC is promising for incorporation into topical formulations for the treatment of autoimmune diseases that affect the skin, such as psoriasis

Lipid core nanocapsules-loaded tacrolimus: Development and evaluation of quality parameters

This study aimed to revalidate an HPLC-based analytical methodology to determine  tacrolimus within lipid-core nanocapsules and to evaluate the quality of such nanosystems. Chromatographic separation was achieved by employing a C18 column as a stationary phase and a ternary mixture of acetonitrile: water: phosphoric acid (700:299:1 v/v) as the mobile phase. The revalidated method proved to be linear in the range of 1-60 µg.mL−1 for tacrolimus (r2 >0.999). Detection and quantification limits were 45.38 ng.mL-1 and 137.51 ng.mL-1, respectively, which assures the methodology sensitivity. The method was also precise (RSD = 1.78% between samples). Besides, the methodology demonstrated accuracy and robustness. The lipid-core nanocapsules-loaded tacrolimus showed exclusively nanosized particles (±190 nm and polydispersity index of ≤v0.2), negative zeta potential (-13.67±1.16), and slightly acidic pH (5.58 ± 0.06), with a content of 98.90±2.32%  and encapsulation rate of 99.23±0.32%.  Tacrolimus-loaded in lipid-core nanocapsules-loaded tacrolimus showed stability for at least 30 days at room temperature and a sustained release profile compared to the drug in solution