NERDG 2026
Abstracts for STP Session 3 – Drug Delivery - Other Routes of Administration – Salon C
Presentation 1
Evaluating In Vitro Release Strategies for Oily Depot Solutions
Saurabh Badole(1), Bo Wan(2), Quanying Bao(3), Rob Ju(4), Diane J. Burgess(1)
(1)University of Connecticut, School of Pharmacy, Storrs, CT 06269, USA, (2)Sanofi, (3)Alexion Pharmaceuticals, Inc., (4)AbbVie Inc.
Purpose:
Oily depot formulations are gaining interest due to their manufacturing efficiency and the growing number of lipophilic drug candidates. However, standardized in vitro release testing (IVRT) methods for parenteral oily depot solutions remain poorly established, and no official compendial method currently exists. This gap can be attributed to the partition controlled release mechanism of oily depots and their high sensitivity to interfacial area and hydrodynamic conditions, making formulation optimization, mechanistic understanding, and quality control challenging. The objective of the current research is to develop a biorelevant, reproducible, and discriminatory IVRT method using compendial dissolution apparatus combined with different adapters.
Methods:
Testosterone cypionate (TC) was selected as a model oily drug formulation, and Q1/Q2-equivalent formulations were prepared to match the reference listed drug (RLD). Formulations were characterized for viscosity, drug content, and visual uniformity. Different surfactant containing release media were screened to evaluate TC solubility and stability, and suitable media was selected for IVRT. Multiple membranes were evaluated for use with adapters. Release testing was performed using USP Type II and Type IV apparatus. Direct addition and adapter-based approaches were compared. Discriminatory capability was assessed by formulating TC in different oils and evaluating release using the IVRT method.
Results:
Media screening identified sodium dodecyl sulphate (SDS) as a suitable surfactant capable of maintaining adequate drug solubility and stability throughout testing. Direct addition of the formulation into the release medium resulted in floating and coalescence of oil droplets, leading to variable and incomplete release due to inconsistent interfacial area. In contrast, adapter based methods confined the formulation, controlled the interfacial area, and produced complete and consistent release profiles. The USP Type II apparatus showed faster drug release compared to the USP Type IV apparatus, likely due to its more turbulent hydrodynamic environment. The optimized methods discriminated between formulations prepared with different oils and demonstrated reproducibility with results comparable to the reference listed drug (RLD) product.
Conclusions:
This work highlights a practical approach to IVRT of oily depot formulations, emphasizing the importance of media selection and controlled interfacial and hydrodynamic conditions for developing reliable and biorelevant IVRT methods suitable for quality control.
Keywords:
Oily depot formulations, long-acting injectables, in vitro release testing, quality control, testosterone cypionate.
Abstracts for STP Session 3 – Drug Delivery - Other Routes of Administration – Salon C
Presentation 1
Evaluating In Vitro Release Strategies for Oily Depot Solutions
Saurabh Badole(1), Bo Wan(2), Quanying Bao(3), Rob Ju(4), Diane J. Burgess(1)
(1)University of Connecticut, School of Pharmacy, Storrs, CT 06269, USA, (2)Sanofi, (3)Alexion Pharmaceuticals, Inc., (4)AbbVie Inc.
Purpose:
Oily depot formulations are gaining interest due to their manufacturing efficiency and the growing number of lipophilic drug candidates. However, standardized in vitro release testing (IVRT) methods for parenteral oily depot solutions remain poorly established, and no official compendial method currently exists. This gap can be attributed to the partition controlled release mechanism of oily depots and their high sensitivity to interfacial area and hydrodynamic conditions, making formulation optimization, mechanistic understanding, and quality control challenging. The objective of the current research is to develop a biorelevant, reproducible, and discriminatory IVRT method using compendial dissolution apparatus combined with different adapters.
Methods:
Testosterone cypionate (TC) was selected as a model oily drug formulation, and Q1/Q2-equivalent formulations were prepared to match the reference listed drug (RLD). Formulations were characterized for viscosity, drug content, and visual uniformity. Different surfactant containing release media were screened to evaluate TC solubility and stability, and suitable media was selected for IVRT. Multiple membranes were evaluated for use with adapters. Release testing was performed using USP Type II and Type IV apparatus. Direct addition and adapter-based approaches were compared. Discriminatory capability was assessed by formulating TC in different oils and evaluating release using the IVRT method.
Results:
Media screening identified sodium dodecyl sulphate (SDS) as a suitable surfactant capable of maintaining adequate drug solubility and stability throughout testing. Direct addition of the formulation into the release medium resulted in floating and coalescence of oil droplets, leading to variable and incomplete release due to inconsistent interfacial area. In contrast, adapter based methods confined the formulation, controlled the interfacial area, and produced complete and consistent release profiles. The USP Type II apparatus showed faster drug release compared to the USP Type IV apparatus, likely due to its more turbulent hydrodynamic environment. The optimized methods discriminated between formulations prepared with different oils and demonstrated reproducibility with results comparable to the reference listed drug (RLD) product.
Conclusions:
This work highlights a practical approach to IVRT of oily depot formulations, emphasizing the importance of media selection and controlled interfacial and hydrodynamic conditions for developing reliable and biorelevant IVRT methods suitable for quality control.
Keywords:
Oily depot formulations, long-acting injectables, in vitro release testing, quality control, testosterone cypionate.
Presentation 2
Kidney-Targeted siRNA Delivery Using Mesoscale Lipid Nanoparticles
Anastasiia Vasylaki (1), Pratyusha Ghosh (1), Shakuntala Sookraj (1), Ryan Williams (1,2)
(1) Department of Biomedical Engineering, City College of New York, New York, NY; (2) Stony Brook University Division of Nephrology and Hypertension, Department of Medicine, Stony Brook, NY
Treatment of chronic kidney disease (CKD) presents a significant challenge due to limited pharmacological options and high drug excretion from the kidneys. It can be addressed by drug delivery using mesoscale nanoparticles (300 – 500 nm), which selectively target the proximal tubular epithelial cells in the kidneys. New therapeutic targets involved in CKD can be accessed with RNA therapies, for which lipid nanoparticles have been proven to be a successful delivery vehicle. Therefore, this research aims to develop a new therapeutic platform for kidney disease treatment using lipid-based mesoscale nanoparticles for nucleic acid delivery.
Mesoscale lipid nanoparticle (MLNP) formulation was prepared containing siRNA cargo, an ionizable lipid, a phospholipid, cholesterol, and a PEGylated lipid, using the nanoprecipitation method. MLNP size, PDI, and zeta potential were characterized via DLS. siRNA encapsulation efficiency was measured using RiboGreen assay. MLNP cytotoxicity to renal epithelial cells was tested using MTT assay. siRNA release from MLNPs was studied in PBS at 37°C. To assess LNP biodistribution, healthy C57/BI/6J mice were injected IV with 50 mg/kg of fluorescently labeled MLNPs. Different groups of mice were sacrificed at 1, 3, 5, and 7 days post-injection, and organs were collected for fluorescent imaging.
Nanoparticle size was optimized to the mesoscale range (300 – 500 nm) through formulation modifications. The largest effect on size was observed from increasing the total lipid concentration. Lipid composition of MLNPs was modified to achieve stable PEGylation required for kidney targeting. Renal epithelial cell treatment with MLNPs in vitro resulted in high cell viability (>85%). MLNPs demonstrated sustained release of >90% siRNA over the 72 h period. Biodistribution study with fluorescently labeled MLNPs showed high kidney accumulation: 3-fold higher fluorescence in the kidneys compared to the liver at Day 1 and a 24-fold difference at Day 5.
In conclusion, we have developed the first, to our knowledge, mesoscale lipid nanoparticle formulation optimized for targeted nucleic acid delivery to the kidneys. The MLNP formulation has demonstrated preliminary indications of safety and high selectivity for the kidneys. Additional studies will be conducted to apply this system for chronic kidney disease treatment.
Keywords:
Lipid nanoparticles, kidney targeting, nucleic acid delivery
Presentation 2
Kidney-Targeted siRNA Delivery Using Mesoscale Lipid Nanoparticles
Anastasiia Vasylaki (1), Pratyusha Ghosh (1), Shakuntala Sookraj (1), Ryan Williams (1,2)
(1) Department of Biomedical Engineering, City College of New York, New York, NY; (2) Stony Brook University Division of Nephrology and Hypertension, Department of Medicine, Stony Brook, NY
Treatment of chronic kidney disease (CKD) presents a significant challenge due to limited pharmacological options and high drug excretion from the kidneys. It can be addressed by drug delivery using mesoscale nanoparticles (300 – 500 nm), which selectively target the proximal tubular epithelial cells in the kidneys. New therapeutic targets involved in CKD can be accessed with RNA therapies, for which lipid nanoparticles have been proven to be a successful delivery vehicle. Therefore, this research aims to develop a new therapeutic platform for kidney disease treatment using lipid-based mesoscale nanoparticles for nucleic acid delivery.
Mesoscale lipid nanoparticle (MLNP) formulation was prepared containing siRNA cargo, an ionizable lipid, a phospholipid, cholesterol, and a PEGylated lipid, using the nanoprecipitation method. MLNP size, PDI, and zeta potential were characterized via DLS. siRNA encapsulation efficiency was measured using RiboGreen assay. MLNP cytotoxicity to renal epithelial cells was tested using MTT assay. siRNA release from MLNPs was studied in PBS at 37°C. To assess LNP biodistribution, healthy C57/BI/6J mice were injected IV with 50 mg/kg of fluorescently labeled MLNPs. Different groups of mice were sacrificed at 1, 3, 5, and 7 days post-injection, and organs were collected for fluorescent imaging.
Nanoparticle size was optimized to the mesoscale range (300 – 500 nm) through formulation modifications. The largest effect on size was observed from increasing the total lipid concentration. Lipid composition of MLNPs was modified to achieve stable PEGylation required for kidney targeting. Renal epithelial cell treatment with MLNPs in vitro resulted in high cell viability (>85%). MLNPs demonstrated sustained release of >90% siRNA over the 72 h period. Biodistribution study with fluorescently labeled MLNPs showed high kidney accumulation: 3-fold higher fluorescence in the kidneys compared to the liver at Day 1 and a 24-fold difference at Day 5.
In conclusion, we have developed the first, to our knowledge, mesoscale lipid nanoparticle formulation optimized for targeted nucleic acid delivery to the kidneys. The MLNP formulation has demonstrated preliminary indications of safety and high selectivity for the kidneys. Additional studies will be conducted to apply this system for chronic kidney disease treatment.
Keywords:
Lipid nanoparticles, kidney targeting, nucleic acid delivery
Presentation 3
Novel phosphoantigen prodrug platform with integrated HILIC–MS/MS bioanalysis for γδ T-cell based cancer immunotherapy.
Girija Pawge (1), Chia-Hung Christine Hsiao (1) and Andrew J. Wiemer (1)
(1) Department of Pharmaceutical Sciences, University of Connecticut, Storrs, CT, United States.
Purpose
The γδ T cells represent a promising cancer immunotherapy modality due to their MHC-independent tumor recognition. Their activation depends on intracellular accumulation of phosphoantigens (pAgs); however, native pAgs are highly polar, susceptible to phosphatases, and poorly membrane permeable. To overcome these concerns, we have developed prodrug approaches, such as aryl acyloxy esters and aryl phosphonamidates to deliver the pAg payload C-HMBP. Understanding prodrug metabolism in plasma and tumor cells is critical to determining effectiveness in cellular and animal models, however the current detection approaches are limited. To rigorously evaluate the activation pathways of these prodrugs we developed a HILIC–MS/MS method to quantify parent prodrug, intermediates, and released C-HMBP payload across biological matrices.
Methods
A lead aryl acyloxy ester-prodrug was compared to an aryl phosphonamidite-prodrug in human plasma, human leukemia cells, and a mouse xenograft model. The HILIC–MS/MS method was developed for sensitive and simultaneous detection of C-HMBP and intermediate metabolites, enabling comprehensive pharmacokinetic analysis. Stability in human plasma was determined. Intracellular activation and payload release were evaluated in leukemia cells. In vivo tumor distribution was evaluated in a leukemia xenograft mouse model. Additionally, the compounds were assessed for γδ T-cell activation against leukemia cells.
Results
The aryl acyloxy ester-prodrug 1 demonstrated a ~100-fold improvement in γδ T-cell–mediated anticancer activity (EC₅₀ = 3 nM) compared to the aryl phosphonamidate-prodrug 2 (EC₅₀ = 130 nM), while maintaining comparable plasma stability (t₁/₂: 12 h vs 18 h, respectively). The HILIC–MS/MS method showed excellent linearity for the C-HMBP payload (r² = 0.9954) with acceptable in vitro matrix effects. Aryl acyloxy ester-prodrugs exhibited rapid and efficient intracellular payload release, correlating strongly with enhanced potency. Although in vivo C-HMBP quantification was limited by matrix effects, ex vivo γδ T-cell anticancer activity of 1 was comparable to 2 in the xenograft model.
Conclusion
This study establishes rigorous mechanistic and analytical framework for phosphoantigen prodrug development, specifically advancing the detection of metabolites in biological matrices. Optimized aryl acyloxy ester-prodrugs enable potent intracellular delivery of C-HMBP and robust γδ T-cell activation, representing a next-generation platform for translational γδ T-cell–based immunotherapies.
Keywords:
Cancer immunotherapy, γδ T-cell, Prodrug, Drug metabolism, HILIC-MS/MS, Bioactivation
Presentation 4
Pulmonary Delivery of Spray-Dried Antimalarial Drug: A novel Inhaled Formulation for Non-Small Cell Ling Cancer Treatment
Meghana Mokashi (1), Naveen Rajana (1), Zia Uddin Masum (1), Yaqin He (2), Vivek Gupta (1)
(1) St. Johns University, (2) Purdue University
Lung cancer is one of the most prevalent forms of cancer and the leading cause of cancer-related mortality worldwide. Among its various types, Non-Small Cell Lung Cancer (NSCLC) constitutes approximately 85% of lung cancer diagnoses. Existing treatment modalities, including surgery, radiation therapy, immunotherapy, and chemotherapy, exhibit significant limitations. There is rising evidence that repurposed medications work extremely well against many cancers and enable a rapid drug development process. In this study, an anti-malarial drug, amodiaquine (AQ), was formulated as a spray-dried amorphous solid dispersion for inhaled therapy of NSCLC. To enhance the feasibility of the formulation design and optimization, a QbD-enabled Central Composite Design (CCD) was utilized, aiming to optimize a formulation with a desired target product profile that includes a maximum yield, the highest drug content, and minimal moisture content. The optimized formulation underwent comprehensive solid-state characterization, revealing an amorphous nature, as evidenced by the absence of crystalline peaks in the X-ray diffraction pattern of the drug. In vitro aerosolization performance demonstrated the suitability of the spray-dried powder for inhalation, with a mass median aerodynamic diameter (MMAD) of 2.4 ± 0.2 µm and a fine particle fraction (FPF) of 58.9 ± 0.6%. The rheometric properties of the powder demonstrated excellent flow characteristics, exhibiting reduced cohesiveness as indicated by FT4 analysis. Furthermore, the optimized formulation exhibited a moisture content of 0.3%, indicating excellent drying efficiency, which aligns with the FT4 analysis results. In vitro cell culture assays conducted on NSCLC cell lines indicated a non-significant difference in IC50 concentrations between the drug and formulation, suggesting that the parameters utilized in the spray drying process did not adversely affect the drug properties. Moreover, safety studies conducted on L2 cells exhibited cell viability exceeding 85%, affirming the safety profile of the formulation for inhalation. Stability studies further demonstrated that the formulation remained stable for two months at room temperature and under refrigerated conditions, without compromising its aerodynamic properties. Collectively, these findings support the potential of inhalable AQ SD as a promising therapeutic strategy for NSCLC. Future in vivo studies and clinical evaluation are warranted to validate translational feasibility in NSCLC management.
Keywords:
Drug Repurposing, Amorphous Solid Dispersion, Spray drying, Solid State characterization, Non-Small Cell Lung Cancer
