Tabriz University of Medical Sciences Advanced Pharmaceutical Bulletin 2228-5881 13 4 2023 11 01 Screening of Cyclodextrins in the Processing of Buserelin Dry Powders for Inhalation Prepared by Spray Freeze-Drying 772 783 10.34172/apb.2023.086 EN Mostafa Rostamnezhad https://orcid.org/0000-0001-7674-8419 Katayoon Mireskandari Mohammad Reza Rouini Samira Ansari Majid Darabi Alireza Vatanara https://orcid.org/0000-0002-4293-8633 Journal Article 10.34172/apb.2023.086 2023 02 11 2023 07 09 Purpose: In this study, we prepared inhalable buserelin microparticles using the spray freeze-drying (SFD) method for pulmonary drug delivery. Raffinose as a cryoprotectant carrier was combined with two levels of five different cyclodextrins (CDs) and then processed by SFD. Methods: Dry powder diameters were evaluated by laser light scattering and morphology was determined by scanning electron microscopy (SEM). Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) analysis were utilized for the determination of crystalline structures. The aerodynamic properties of the spray freeze-dried powders were evaluated by twin stage impinger (TSI) and the stability of prepared samples was assessed under normal and accelerated conditions. Results: The prepared powders were mostly porous spheres and the size of microparticles ranged from 9.08 to 13.53 μm, which are suitable as spray-freeze dried particles. All formulations showed amorphous structure confirmed by DSC and XRD. The aerosolization performance of the formulation containing buserelin, raffinose and 5% beta-cyclodextrin (β-CD), was the highest and its fine particle fraction (FPF) was 69.38%. The more circular and separated structures were observed in higher concentrations of CDs, which were compatible with FPFs. The highest stability was obtained in the formulation containing hydroxypropyl beta-cyclodextrin (HP-β-16. CD) 5%. On the contrary, sulfobutylether beta-cyclodextrin (SBE-β-CD) 5% bearing particles showed the least stability. Conclusion: By adjusting the type and ratio of CDs in the presence of raffinose, the prepared formulations could effectively enhance the aerosolization and stability of buserelin. Therefore, they can be proposed as a suitable career for lung drug delivery.