(T1030-07-38) Nanovesicle Delivery Systems Containing Doxorubicin Hydrochloride and Paclitaxel for Breast Cancer Treatment

Purpose: Breast cancer is a disease in which cells in the breast grow out of control and can be of many kinds. If left untreated, this can metastasize to distant organs like bones, liver, lungs, and brain which is also a major cause of morbidity.¹ Currently, chemotherapy, immunotherapy, surgery, and gene therapy are used to treat breast cancer. Conventional treatment options come with numerous shortcomings like low bioavailability, short circulation time, and toxicity to the normal cells. To overcome these difficulties, nano-delivery approach has been thoroughly investigated for the treatment of breast cancer. Nanovesicles are capable to entrap both lipophilic and hydrophilic drugs in the lipid bilayers and the aqueous core, respectively.² The objective of this study was to develop and characterize nanovesicles namely liposomes, transfersomes, and niosomes containing doxorubicin hydrochloride and paclitaxel. The hypothesis of this study was that both drugs in a single nanovesicle will enhance targeting, reduce drug dosing, and toxicity with increased patient compliance.

Methods: An UPLC method was developed and validated for the simultaneous determination of both drugs in aqueous solutions. Separation was achieved using a C-18 column, with isocratic mobile phase consisting of 44.5% (v/v) acetonitrile, 16.5% (v/v) methanol, and 39% (v/v) of 0.1M ammonium acetate buffer with a flow rate of 0.3 mL/min. A PDA detector at 234 nm was used to detect both drugs. This method was validated for linearity, precision, sensitivity, and accuracy. Thin-film hydration method was used to formulate both blank and drug-loaded liposomes, transfersomes, and niosomes. Liposomes consisted of cholesterol and soy lecithin. Transfersomes contained tween 80 instead of the cholesterol, and niosomes contained diacetyl phosphatidylcholine, span 80, and cholesterol. All these lipids and surfactants were dissolved in a suitable organic solvent and evaporated in a rotary evaporator under reduced pressure. The thin film formed was hydrated with 0.2 mm filtered de-ionized water and bath sonicated for 30 minutes. These nanovesicles were further subjected to size reduction through an emulsifier (Avestin, Inc.) at 1650 mbar pressure. Nanovesicles were tested for particle size, polydispersity index, and zeta potential in the Zetameter (Nanobrook 90 Plus PALS, Brookhaven). Paclitaxel (3-5% w/w) was loaded by the active loading method, and doxorubicin hydrochloride (1 mg/mL) was loaded remotely after hydration of the thin film.

Results: The retention time of doxorubicin hydrochloride was 1.53 minutes. Paclitaxel was eluted at 4.06 minutes. Standard curves for both drugs were linear over a concentration range from 3.13 mg/mL to 50 mg/mL. The precision (day-to-day and within-day) and, accuracy of the method is provided in Table 1. The particle size for blank and drug loaded liposomes, transfersomes and niosomes range from 150nm-250nm. Similarly, PDI and zeta potential varied from 0.14-0.20 and -0.56mV-0.54mV respectively and shown in Table 2. Both blank and drug loaded nanovesicles were physically stable for a minimum of five days when stored at both room temperature and 4⁰C.

Conclusion: UPLC method validity as per ICH and USP guidelines for specificity, linearity, precision, and accuracy was found to be within the acceptable range. The characterization of nanovesicles confirms that they are physically stable and are in nano size ranges. The drug loaded nanovesicles have a slight negative zeta potential and are polydisperse. Furthermore, encapsulation efficiency and drug release study can be done to identify the best nanovesicle for the co-delivery of paclitaxel and doxorubicin hydrochloride for the treatment of breast cancer.

References: 1. Majeed W, Aslam B, Javed I. et al. Breast cancer: major risk factors and recent developments in treatment. APJCP. 2014; 15:3353–3358.
2. Wadhwa, S., Garg, V., Gulati, M., Kapoor, B., Singh, S. K., & Mittal, N. (2019). Nanovesicles for Nanomedicine: Theory and Practices. Methods in molecular biology (Clifton, N.J.), 2000, 1–17. https://doi.org/10.1007/978-1-4939-9516-5_1

Acknowledgments: Financial support from School of Pharmacy and Health Professions, Creighton University
Conflict of Interest Statements: We confirm that there are no conflicts of interest associated with this work and there has been no significant financial support for this work that could have influenced its outcome.





Table 2: Characterization Study of Nanovesicles