Fabrication and Characterisation of Taste-Masked Orally Dissolving Films Containing Ondansetron Hydrochloride Using Novel Poly(Amide-Thioester) Nanocapsules Based on L-Cysteine Amino-Acid

Abstract Purpose Ondansetron (OND) is 5-HT3 receptor antagonist commonly used to treat chemotherapy-induced nausea and vomiting. However, its short half-life, low bioavailability, and intense bitter taste have led to decreased patient compliance. Administering it via an oromucosal film encapsulated into polymeric nanoparticles without the need for water is advantageous due to the difficulty of taking the medication with water when experiencing nausea. Therefore, the aim of this study was to synthesise polymeric nanoparticles using L-cysteine amino acid to encapsulate the bitter-tasting OND and develop paediatric oral dissolving films (ODFs) using them. Method Cysteine-based poly(amide-thioester) nanoparticles (CYS-PATE NPs) were developed using the one-step interfacial polycondensation technique between aqueous and organic phases. The nanoparticles were extensively characterised and incorporated into ODFs prepared using various polymers (HPMC, Pullulan and Polyethylene oxide (PEO)). Results OND-loaded CYS-PATE NPs (OND/CYS-PATE NPs) were also synthesised with a particle size of 319.7 ± 44.59 nm and a zeta potential of -32.07 ± 0.31. The semi-crystalline nature of both the resultant CYS-PATE NPs and the OND-encapsulated ones was confirmed by DSC and XRD characterisation. In-vitro release studies of optimal formulation (OND/CYS-PATE NPs) showed a total release of 58 µg of OND in 10 mL of artificial saliva after 10 min, equivalent to 5.8 µg/mL, which did not reach the OND bitterness threshold (7.5 µg/mL). Incorporating these NPs into film-forming polymers led to the development of 0.1% HPMC ODFs with homogeneity and a good disintegration time of 49.33 ± 3.99 s. Conclusions This study confirms that encapsulating bitter actives in CYS-PATE NPs effectively masked the taste of bitter soluble APIs, formulating them into more palatable forms that can enhance acceptability and adherence, particularly in paediatrics CINV. Graphical Abstract Schematic representation diagram of synthesis and characterisation of L-cysteine amino acid based poly (thioester amide) nanoparticles containing OND for taste masking of it