Chitosan-encapsulated niosomes for enhanced oral delivery of atorvastatin

Atorvastatin is the most commonly used hypolipidemic drug. It provides excellent protection against cardiovascular disease especially in subjects having high risk factors. However, atorvastatin has problematic biopharmaceutical characteristics due to low dissolution rate and extensive pre-systemic disposition. This contributed to reduced oral bioavailability and necessitated prescription of higher doses with subsequent unwanted side effects.

Highlights

Atorvastatin was successfully loaded into chitosan-encapsulated niosomes.

Both chitosan-encapsulated and standard niosomes were in the form of nanosized spherical vesicles.

Chitosan-encapsulated and standard vesicles liberated atorvastatin at the same pattern.

Oral administration of atorvastatin formulations reduced the blood cholesterol level.

Chitosan-encapsulated niosomes were more efficient than standard vesicles and both were better than drug suspension.

The aim of this work is to probe chitosan-encapsulated niosomes for enhanced oral delivery of atorvastatin. Standard niosomes comprising Span 60, cholesterol and dicetyl-phosphate were prepared. Chitosan-encapsulated vesicles were prepared by coating the standard niosomes with chitosan followed by crosslinking with tripolyphosphate. Niosomes were characterized with respect to their morphology, size, atorvastatin entrapment and release. The antihyperlipidemic effect of atorvastatin-loaded niosomes was assessed after oral administration to hyperlipidemic mice. Both chitosan-encapsulated and unencapsulated vesicles were spherical. Chitosan-encapsulated niosomes had significantly lower particle size (96.9 nm) compared with unencapsulated niosomes (143.2 nm).

The entrapment efficiency values were 57% and 55.5% for chitosan-encapsulated and unencapsulated niosomes, respectively with both formulations showing similar release pattern. Biochemical and histopathological evaluations of the therapeutic efficacy of different atorvastatin formulations in an in vivo model of hyperlipidemia revealed that the antihyperlipidemic effect could be ranked as follows: chitosan-encapsulated niosomes > unencapsulated niosomes > drug suspension. The study introduced chitosan-encapsulated niosomes as promising carrier for oral delivery of atorvastatin.

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Article information: Noha D. Fayed, Ahmed E. Goda, Ebtesam A. Essa, Gamal M. El Maghraby, Chitosan-encapsulated niosomes for enhanced oral delivery of atorvastatin, Journal of Drug Delivery Science and Technology, 2021. https://doi.org/10.1016/j.jddst.2021.102866.