RESUMEN
Nose-to-brain drug delivery has been proposed to overcome the low absorption of drugs in central nervous system due to the absence of brain-blood barrier in the olfactory nerve pathway. However, the presence of a mucus layer and quick clearance limit the use of this route. Herein, amphiphilic methacrylic copolymer-functionalized poly(ε-caprolactone) nanocapsules were proposed as a mucoadhesive system to deliver olanzapine after intranasal administration. In vitro evaluations showed that these nanocapsules were able to interact with mucin (up to 17% of increment in particle size and 30% of reduction of particle concentration) and nasal mucosa (2-fold higher force for detaching), as well as to increase the retention of olanzapine (about 40%) on the nasal mucosa after continuous wash. The olanzapine-loaded amphiphilic methacrylic copolymer-functionalized PCL nanocapsules enhanced the amount of drug in the brain of rats (1.5-fold higher compared to the drug solution). In accordance with this finding, this formulation improved the prepulse inhibition impairment induced by apomorphine, which is considered as an operational measure of pre-attentive sensorimotor gating impairment present in schizophrenia. Besides, nanoencapsulated olanzapine did not affect the nasal mucosa integrity after repeated doses. These data evidenced that the designed nanocapsules are a promising mucoadhesive system for nose-to-brain delivery of drugs.
Asunto(s)
Benzodiazepinas/administración & dosificación , Metacrilatos/química , Mucinas/química , Nanocápsulas/química , Poliésteres/química , Esquizofrenia/tratamiento farmacológico , Administración Intranasal , Animales , Antipsicóticos/administración & dosificación , Antipsicóticos/química , Benzodiazepinas/química , Encéfalo/efectos de los fármacos , Difusión , Nanocápsulas/ultraestructura , Olanzapina , Tamaño de la Partícula , Ratas , Esquizofrenia/diagnóstico , Tensoactivos/química , Resultado del TratamientoRESUMEN
This study aimed to investigate the pharmacokinetics, tissue distribution and antipsychotic activity of olanzapine administered as free drug (OLA-FREE) or loaded into lipid-core nanocapsules (OLA-LNC). OLA-LNC were successfully developed with a particle size of 142 ± 4 nm and a zeta potential of -19.6 ± 0.6 mV. Pharmacokinetics and tissue distribution studies were carried out after the administration of free and nanoencapsulated olanzapine (10 mg/kg) by intraperitoneal route to male Wistar rats. Higher olanzapine concentrations and AUC(0-12 h) were found in plasma and tissues evaluated after the administration of OLA-LNC compared to the drug in the free form, resulting in a relative bioavailability of 226.7% in the plasma. As a result olanzapine loaded lipid-core nanocapsules presented pronounced and long-lasting effects on central nervous system. These nanocapsules (10 mg/kg, i.p.) significantly diminished the stereotyped behavior induced by D,L-amphetamine up to 12 hours whereas olanzapine free-form (10 mg/kg, i.p.) was effective during 03 hours only. Moreover, olanzapine loaded lipid-core nanocapsules (1.0 mg/kg, i.p.) have shown a marked sedative effect and also prevented the prepulse inhibition disruption induced by apomorphine at lower dose than olanzapine in free-form (2.5 mg/kg, i.p.). Herewith, we point to the nanoencapsulation as a strategy for reducing the concentration of olanzapine in pharmaceutical formulations.
Asunto(s)
Benzodiazepinas/administración & dosificación , Benzodiazepinas/farmacocinética , Encéfalo/metabolismo , Nanocápsulas/química , Esquizofrenia/tratamiento farmacológico , Esquizofrenia/metabolismo , Animales , Antipsicóticos/administración & dosificación , Antipsicóticos/química , Antipsicóticos/farmacocinética , Benzodiazepinas/química , Disponibilidad Biológica , Encéfalo/efectos de los fármacos , Difusión , Tasa de Depuración Metabólica , Nanocápsulas/administración & dosificación , Nanocápsulas/ultraestructura , Olanzapina , Especificidad de Órganos , Tamaño de la Partícula , Ratas , Ratas Wistar , Resultado del TratamientoRESUMEN
Olanzapine is an atypical antipsychotic drug, whose chronic use has been associated with the development of potential adverse effects such as weight gain and cardio-metabolic disorders like hypercholesterolemia and diabetes. To circumvent these side effects, the controlled release of olanzapine is a promising approach to improve adhesion of schizophrenic patients to the treatment. An innovative strategy to prolong drug release consists of loading the drug into biodegradable polymeric lipid-core nanocapsules. In this study, particle size, polydispersity, pH, zeta potential and drug loading of olanzapine-loaded lipid-core nanocapsules were analyzed. Weight gain, biochemical parameters and antipsychotic activity were evaluated in male Wistar rats. The lipid-core nanocapsules had a mean diameter of 156 +/- 13 nm, a polydispersity index lower than 0.1, a pH value of 6.12 +/- 0.14, zeta potential of -17 +/- 2.40 mV and encapsulation efficiency close to 100%. The animals treated with olanzapine-loaded lipid-core nanocapsules showed significantly lower weight gain (63.4 +/- 19.6 g) and total cholesterol levels (66.2 +/- 3.5 g x dl(-1)), compared to those administered with free olanzapine (112.6 +/- 10.3 g and 90.4 +/- 2.4 g x dl(-1)), respectively. Additionally, a more prolonged antipsychotic action was observed in the stereotyped behavior animal model induced by D,L-amphetamine, which affords to conclude that nanoencapsulation is a promising alternative to treat schizophrenic patients.