(M1230-03-16) Nose to Brain Delivery of Donepezil after the Administration of HPMC-Me-β-CD-PEG400 Based Nasal Films in C57BL/6J Mice

Purpose: Pharmacokinetic (PK) study of novel polymer nasal film (NF) for nose-to-brain (NTB) delivery of Donepezil Hydrochloride (DH) in C57BL/6J mice, after intranasal (IN) and per os administration.

Methods: Eight-week-old Black 6 (C57BL/6J) mice were randomly divided in two groups, per os (PO) and intranasal (IN), and each one received different treatment as follows: a) PO group was further divided in 7 subgroups, each subgroup of animals representing one sampling time point (15, 30, 45, 60, 120, 240, and 360 min after the treatment); b) IN group was further divided in 8 subgroups, each subgroup of animals) representing one sampling time point (5, 10, 15, 30, 45, 60, and 120 min after the treatment). PO group received 0.2 mL of the 1.25 mg/mL (10 mg/kg) DH solution via gavage method, while IN group received one NF intranasally, corresponding to 0.1 mg of DH (4 mg/kg). Blood and tissue samples were collected at the selected time points after animal sacrificed, properly treated, and analyzed with HPLC‐PDA. Dose selection for per os administration was based on literature [1] PK data. Intranasal dose was 2.5-times lower than per os, expecting to achieve satisfying drug levels taking advantage of NTB delivery [2-3]. Sparse sampling non-compartmental analysis (NCA) was performed for all in vivo data using Phoenix® 8.3 (Certara, Princeton, NJ, USA), to determine serum and brain PK parameters. The area under the concentration‐time curve (AUC_inf) was calculated according to the log‐linear trapezoidal method with extrapolation to infinity by dividing the last concentration by the terminal slope, λ. The terminal slope was estimated by linear regression analysis on the last three or four points of the log transformed concentration vs time plot. The relative IN bioavailability (F_rel) was measured by comparing the respective AUCs after IN and per os administration. Also, Drug Targeting Efficiency Percentage (DTE) and NTB Direct Transport Percentage (DTP) indexes that have been reviewed by Kozlovskaya et al. (2014) [4], were calculated to evaluate the direct drug transport to the brain, assuming a linear PK of DH [5].

Results: The DH brain profile obtained after the oral and IN administration of the drug are presented in Figure 1. The administration of NF resulted in high DH brain levels, even if a lower dose was given. C_max was achieved within 15 min after NF positioning into the nasal cavity and it was 5.6 times higher than oral DH brain levels. Moreover, the application of NCA revealed a 2.8 times higher serum AUC_0-t compared to that obtained by the per os curve. Accordingly, in Figure 2, DH serum profile demonstrated a faster and more extended systemic absorption after the nasal delivery of the drug, producing C_max 3.9 higher compared to oral route. The relative bioavailability of DH in brain and serum was found equal to 7.55 and 3.95 respectively, proving the improvement of DH distribution either in brain or bloodstream. Furthermore, the DTE was higher than 100, equal to 184% identifying a more efficient brain targeting via nasal route compared to the oral one. The value of DTP, equal to 45% indicates that a significant fraction of IN dose entered the brain directly via NTB, in addition to the amount reaches the tissue through the systematic circulation, as also depicted in the double-peak profile of Figure 1.

Conclusion: A comparative PK study of IN vs per os administration of DH was performed in C57BL/6J mice. The PK parameters estimated by NCA sparse data methodology illustrated the effectiveness of IN administration either in brain targeting or to reach the bloodstream. Higher drug levels were achieved at both sites, compared to those after oral delivery. Thus, nasal films manage to increase the relative bioavailability in brain and serum after the administration of 2.5 times smaller dose, taking advantage of the NTB delivery and the avoidance of first-pass effect.

References: 1. Shin, C. Y., Kim, H. S., Cha, K. H., Won, D. H., Lee, J. Y., Jang, S. W., & Sohn, U. D. (2018) The Effects of Donepezil, an Acetylcholinesterase Inhibitor, on Impaired Learning and Memory in Rodents. Biomolecules & therapeutics, 26(3), 274–281. doi: 10.4062/biomolther.2017.189
2. Dhuria, S.V., Hanson, L.R., Frey, W.H. 2nd. (2010) Intranasal delivery to the central nervous system: mechanisms and experimental considerations. J Pharm Sci, 99(4):1654-73. doi: 10.1002/jps.21924
3. Laffleur, F., & Bauer, B. (2021) Progress in nasal drug delivery systems. International Journal of Pharmaceutics, 607, 120994. doi: https://doi.org/10.1016/j.ijpharm.2021.120994
4. Kozlovskaya, L., Abou-Kaoud, M., Stepensky, D. (2014) Quantitative analysis of drug delivery to the brain via nasal route. J Control. Release. 189, 133–140. doi: https://doi.org/10.1016/j.jconrel.2014.06.053
5. Szpunar, G.J., Albert, K.S., Bole, G.G., Dreyfus, J.N., Lockwood, G.F., Wagner, J.G. (1987) Pharmacokinetics of flurbiprofen in man. I. Area/dose relationships. Biopharm. Drug Dispos. 8, 273–283. doi: https://doi.org/10.1002/bdd.2510080308.

Acknowledgements:This work was supported by the Hellenic Foundation for Research and Innovation (H.F.R.I.) in the context of the "3rd Announcement of Scholarship for PhD candidates".


Brain concentration-time profiles of DH administered intranasally, as nasal film (IN) and orally, via gavage method (PER OS). The data are presented as mean ± S.D., n=6 for IN group, n=5 for per os group.


Serum concentration-time profiles of DH administered intranasally, as nasal film (IN) and orally, via gavage method (PER OS). The data are presented as mean ± S.D., n=6 for IN group, n=5 for per os group.


Non compartmental analysis using sparse data methodology