(W0930-01-03) Optimization of Phospholipid Based Nano Drug Delivery System of Osimertinib - An In Vitro Drug Release, Ex Vivo Permeability Study

Purpose: Osimertinib (OSM) is a tyrosine kinase inhibitor (TKI) used in non-small cell lung cancer (NSCLC). However, it exhibits low permeability and low tumor selectivity, leading to post-treatment adverse effects . Therefore, the aim of this study was to develop a phospholipid based nano drug delivery system of OSM to improve the permeability and targeted drug delivery.

Methods: Phospholipid based nano drug delivery system (PBNDDS) of OSM was developed by a thin film hydration technique using active and passive drug loading methods. A full factorial design of experiment (DoE) [3 factors at 2 levels] was used to statistically evaluate the impact of process parameters (Drug Loading method, Sonication Time) and material attributes (Type of Stabilizers) on average particle size, polydispersity index (PDI) and entrapment efficiency (EE) of OSM nano-preparations using Minitab version 22 software (Table 1). The average particle size, EE (%), in-vitro drug release, and ex-vivo drug permeability were evaluated using Dynamic Light Scattering (DLS), UV spectrophotometry, dialysis membrane, and Franz diffusion cell.

Results: Dynamic light scattering data showed that the average particle size for the PBNDDS batches of OSM using DoE were in the range of (20 - 1120 nm). PBNDDS batches of OSM showed PDI and EE (%) in the range of (0.26 ± 0.03 to 0.75 ± 0.05) and (48.55 ± 0.91% to 81.62 ± 0.39%) respectively (Table 1). Sonication time, stabilizer types and drug loading methods found to have significant impact (p < 0.05) on average particle size and EE (%) for the PBNDDS batches of OSM. Sonication time was observed to be the most critical factor affecting the average particle size (Figure 1a). Process parameters perspective, prolong sonication time (40 minutes) exhibited low average particle size compared to shorter duration of sonication (20 minutes), while active drug loading method showed low average particle size compared to passive drug loading for the PBNDDS batches of OSM prepared using both stabilizers (Table 1). Material attributes perspective, PBNDDS batches of OSM prepared using Tween 80 exhibited low average particle size compared to batches prepared using poloxamer 407 (Table 1). This phenomenon may be related to lower molecular weight of tween 80 (MW: 1310 Dalton's), which stabilizes OSM nanoparticles more efficiently due to their ability to cover interfacial surfaces rapidly than higher molecular weight poloxamer 407 (MW: 12,600 Dalton's) [2-3]. Drug loading methods and stabilizer types were found to be the most critical factors affecting the EE (%) for the PBNDDS batches of OSM (Figure 1b). PBNDDS of OSM prepared using active drug loading method with poloxamer 407 showed highest EE (%) 81.62 ± 0.39% compared to batches prepared using passive loading method with both stabilizers (Table 1). The above results suggested that the lowest average particle size was achieved for the batch prepared using tween 80 (Batch no. TB 8, size: >21.77±3.33nm, EE:52.51 ± 0.19%), while highest EE (%) was observed for the batch prepared using poloxamer 407 (Batch no. TB 6, size: 100.54 ± 2.49 nm, EE: 81.62 ± 0.39 %) (Table 1). Therefore, in this study, these two batches were considered as optimized batches for further in-vitro drug release and ex-vivo permeability study. In-vitro drug release study data indicated that two optimized batches of OSM showed sustained drug release (TB 6: 38.01 ± 0.15% and TB 8: 21.66 ± 1.11%) compared to raw OSM suspension (68.42 ± 1.05 %) (Figure 2a). However, the optimized batch (TB-6) of OSM showed significantly better initial release (within 5 hours) compared to the batch (TB-8) (Figure 2a). Ex-vivo permeability study data exhibited that two optimized batches of OSM showed around 2.2-fold greater permeation after 3 hours compared to raw OSM suspension, however no significant (p > 0.05) difference was observed in permeability study between the optimized batches of OSM Stability study data suggested that batch no. TB 6. prepared using poloxamer 407 showed significant (p < 0.05) growth in average particle size (initial size: 100.54 ± 2.49 nm) after 3 months (196.67± 2.74 nm). However, batch no. TB 8. developed using tween 80 showed no significant (p > 0.05) difference in average particle size (initial size: 21.77 ± 3.33 nm) after 3 months (28.22 ± 3.25 nm).

Conclusion: The optimized PBNDDS batches of OSM developed using thin film hydration method showed average particle size of ≤100 nm with EE (%) ≥ 81%. Sonication time, drug loading methods and stabilizer types found to have marked impact on average particle size and encapsulation efficiency. In-vitro drug release data showed significant improvement in sustained drug release of OSM with initial burst for the optimized batch prepared using poloxamer 407 (TB 8). Ex-vivo permeability study data exhibited 2.2-fold greater permeation for the optimized PBNDDS batches of OSM compared to raw OSM suspension. Further in-vivo study will be conducted regarding the targeted delivery of OSM nano preparations for non-small cell lung cancer.

References: [1] S. K. Kuna and A. D. Choppala, “Biocompatible osimertinib nanoliposomes coated with PEGylated hyaluronic acid enhanced tumor selectivity and cytotoxicity via CD44-mediated NSCLC targeting: Development, characterization and in-vitro biochemical studies,” J. Appl. Pharm. Sci., vol. 13, no. 7, pp. 204–213, 2023.
[2] S. G. Salem, A. R. Gardouh, and S. Gad, “C: Parameter Optimization of Solid Lipid Nanoparticles Formulation,” Rec. Pharm. Biomed. Sci., vol. 4, no. 2, pp. 1–7, 2020.
[3] H. A. Ebrahimi, Y. Javadzadeh, M. Hamidi, and M. B. Jalali, “Repaglinide-loaded solid lipid nanoparticles: effect of using different surfactants/stabilizers on physicochemical properties of nanoparticles,” DARU J. Pharm. Sci., vol. 23, pp. 1–11, 2015.

Acknowledgements: The authors would like to thank North South University, Bangladesh and all other collaborative universities and institutions for supporting this project work.


Table 1. Average particle size (nm), PDI and Entrapment Efficiency (EE%) of PBNDDS batches of OSM prepared using DoE


Figure 1. Pareto chart for PBNDDS batches of OSM for (a) average particle size and (b) entrapment efficiency (EE%)


Figure 2. (a) In-vitro drug release and (b) ex-vivo permeability study for the optimized PBNDDS batches of OSM and raw OSM suspension