Oral Dissolving Film of Rivastigmine: Optimization Using Factorial Design

Abstract

Purpose: Due to impairments in memory and judgment, it is difficult for dementia patients to understand why they need medicine. Moreover, they often have swallowing difficulties. In this investigation, an oral dissolving film of rivastigmine tartrate (RT-ODF) was developed, offering a unique and convenient formulation for dementia patients. Methods: RT-ODF was developed using a solvent-casting technique. Sodium alginate and sodium carboxymethyl cellulose were used as film-forming polymers, and glycerol was used as a plasticizer. A full factorial design (32) was employed to estimate the impact of two factors at three levels: polymer concentration (1, 1.5, and 2% w/v) and plasticizer concentration (30, 40, and 50% w/v) on the responses, i.e., the tensile strength (TS), the disintegration time (DT), and the quantity of drug released (Q10 min). Results: The optimized formula (A1) that had the highest desirability value (0.923) exhibited the lowest tensile strength (3.67 ± 0.72 MPa), the shortest disintegration time (20 ± 2.0 s), and the highest percentage of drug released after 10 min (97.12 ± 2.01%). It was composed of 1% w/v sodium alginate (ALG-Na) and plasticized with 30% w/v glycerol. The pharmacokinetic study revealed that the RT-ODFs enhanced the drug’s bioavailability by 1.91-fold relative to the reference product (Exelon® capsule). Conclusion: Oral dissolving films of rivastigmine tartrate could be a promising approach to promote drug bioavailability and convenience for geriatric patients.