Abstracts for Academic Research Award (ARA) Presentations
Moderator: Dimple Modi
Presentation 1
PNA-mediated targeting of the oncogenic miRNA 17-92 cluster
Ivy Browne, University of Saint Joseph, [email protected]
Purpose
RNA therapeutics has made remarkable progress in recent years with the FDA approval of RNA targeting drugs. MicroRNAs (miRs) occupy a central position in RNA therapeutics. MiRs are 21-25 nucleotides long non-coding RNAs that regulate gene expression by binding to mRNAs. A 6-9 nucleotide long seed region of a miR binds with 3’-UTR of a mRNA, allowing a single miR to regulate the expression of several mRNAs. Different miRs share a common seed region. An effective strategy for targeting multiple miRs is targeting the seed region with antisense molecules. The miR17-92 cluster is upregulated in several cancers, making it an ideal therapeutic target. Very few studies have employed antisense molecules to target miR 17-92 cluster. Antisense molecules targeting miR 17-92 would broaden the scope of cancer therapies. We designed cationic peptide nucleic acid (PNA) based antisense molecules to target miR 17 family. PNA is a DNA/RNA mimic in which the phosphodiester backbone is replaced with a neutral N-(2- aminoethyl) glycine backbone. PNA binds to miRs with high affinity and is resistant to enzymatic degradation. We have designed short gamma PNA probes with increased specificity and robust binding affinity. We hope our findings provide valuable insights for developing cancer therapy through miR inhibition.
Methods
We conducted biophysical characterization of PNA-miR complexes using gel shift binding assays and thermal denaturation assays to confirm the binding of designed PNAs to the target sequences and assess the PNA-miR heteroduplex's stability. We are evaluating the efficacy of PNA probes in various cancer cell lines (U2932, MCF-M, DLD1, A549) through cell viability, gene expression, and protein expression assays.
Results
We observed that all PNA probes bind to different target sequences of the miR-17 family with high affinity and stability. We confirmed the cellular uptake of fluorophore (TAMRA) conjugated PNAs using flow cytometry and confocal microscopy. Additionally, we noted a downregulation in the expression of targeted miRs in U2932 cell lines.
Conclusion
We successfully synthesized cationic PNAs targeting the seed region of the miR-17 family, demonstrating high cellular uptake and established in vitro efficacy to develop a potential cancer therapeutic.
Presentation 2
Chemically engineered nucleic acids targeting VEGFA genomic DNA for cancer therapy
Angana De, University of Connecticut, [email protected]
Purpose
In solid tumors, the tumor cells experience a deficiency in nutrients and oxygen; consequently, abnormal vasculature develops to alleviate these inadequacies. In 72% of solid tumors, Vascular Endothelial Growth Factor A (VEGFA) is upregulated, playing a pivotal role in cell proliferation, tumor growth, and angiogenesis. The upregulation of VEGFA transcription occurs through the dimerization of the Hypoxic Inducible Factor-1 (HIF-1α and HIF-1β) pathway within the hypoxic tumor microenvironment. Therefore, as a proof of concept, inhibiting the interactions between the HIF-1 dimer and the Hypoxic Responsive Element (HRE) on the VEGFA gene may impede its transcription in cancerous tissues. Consequently, the sequence-specific targeting of genomic DNA that encompasses the HRE to silence the gene could provide new avenues in cancer therapy. Our objective is to target the genomic DNA of VEGFA using next-generation gamma-modified Peptide Nucleic Acid (γPNA) conjugated with a Nuclear Localization Signal (NLS) peptide, thereby enhancing its delivery to the nucleus and therapeutic efficacy in both in vitro and xenograft mouse models of triple-negative breast cancer (TNBC).
Methods
The hypoxic responsive element (HRE) of the VEGFA gene is situated upstream of the promoter region, which plays a key role in regulating transcription. The γPNA-NLS and its scrambled control are synthesized via solid-phase chemistry and tested for their ability to invade genomic DNA at the target site in vitro, using a PCR amplicon assay across various tumor cell lines. Additionally, nuclear uptake was confirmed through microscopic analysis. To assess the efficacy of the γPNA-NLS, we conduct gene expression studies and protein analysis of VEGFA and its downstream targets. Moreover, we performed cell viability and proliferation assays to evaluate the effectiveness of targeting the HRE of VEGFA. We also analyzed survival rates in a TNBC xenograft mouse model after administering γPNA-NLS to determine its anti-tumor activity in vivo.
Results
Cell culture studies (PCR amplicon assay and microscopy) confirmed that γPNA-NLS shows nuclear uptake and targets the genomic DNA of VEGFA in TNBC, lung cancer, and cervical cancer cell lines. Gene expression and protein analysis suggested the efficacy of γPNA-NLS in downregulating VEGFA levels and its downstream targets. We established the effectiveness of γPNA-NLS in reducing cell viability and cell proliferation. Furthermore, survival analysis in the TNBC xenograft mouse model strongly indicated the anti-tumor efficacy of γPNA-NLS, demonstrating a two-fold decrease in tumor growth compared to the scramble control.
Conclusion
We have sequence specifically targeted the genomic DNA of the VEGFA using γPNA-NLS to downregulate its transcription in vitro, subsequently inhibiting tumor growth in a TNBC mouse model. The results presented in this study establish a novel platform to mitigate tumor burden by targeting the genomic DNA.
Presentation 3
CFD-DEM modelling of Suspension Mixing in Pharmaceutical Manufacturing
Saeed Najafian, University of Connecticut, [email protected]
Purpose
Mixing is a vital unit operation in the manufacturing of large and small molecules, offering benefits such as uniform composition and improved dissolution of components. Solid-liquid mixing can be categorized by particle density, encompassing the suspension of denser particles and the dispersion of floating particles with lower density. In this study, we used a coupled computational fluid dynamic (CFD) and Discrete Element Method (DEM) approach to model floating particle mixing. By integrating fluid flow equations with discrete particle interactions, this method provides a powerful tool to investigate and optimize complex multiphase flows, reducing the time, cost, and material requirements associated with experimental studies.
Methods
An Eulerian-Lagrangian approach was employed to model solid-liquid mixing, where the fluid phase is treated in a continuum framework and each particle is tracked at a discrete level. This coupled CFD-DEM technique offers valuable particle scale insights, making it well-suited for analyzing mixing and segregation. Although several researchers have applied CFD-DEM to various mixing processes, limited literature exists on modeling the floating particles. To address this gap, we developed a model using ANSYS FLUENT and ROCKY to examine the mixing and segregation behavior of drug substances in a HyPerforma mixing tank.
Results
Several simulations were performed to find out the best mesh size and structure for the model. A tetrahedron mesh, about 5 times larger than particle size was chosen. Simulations with different impeller speed, particle size and particle concentration were performed. It was observed that by increasing the impeller and particle concentration speed the drawdown and distribution of the floating particles will improve. However, by increasing the particle size, due to increase in the particle inertia the drawdown and distribution over the mixing tank was reduced.
Conclusion
The coupled CFD-DEM approach proved effective in modeling the behavior of floating particles and identifying key factors such as impeller speed, particle size, and particle concentration that influence mixing performance. By combining fluid flow equations with discrete particle dynamics, this approach delivers essential insights at the particle scale while offering a robust, scalable solution for process design and optimization. Consequently, the framework contributes to more efficient, cost-effective, and reliable pharmaceutical manufacturing.
Presentation 4
Preparation and characterization of an ultraflexible liposomal gel for transdermal delivery of a novel pan-RAS inhibitor for the treatment of melanoma cancer
Shivani A. Dave, Massachusetts College of Pharmacy, [email protected]
Purpose
Ultraflexible liposomal gels (UFLs) offer a promising approach to delivering lipophilic compounds topically . This study focuses on the preparation and characterization of UFLs designed to improve the delivery of a novel pan-RAS inhibitor, ADT-007, to treat early-stage melanoma . ADT-007 potently and selectively inhibits cancer cells with mutant or activated RAS by binding RAS in a nucleotide-free state, blocking GTP loading, and disrupting RAF and PI3K binding, thereby suppressing MAPK and AKT signaling . The efficacy of free and encapsulated ADT-007 was evaluated in human melanoma cancer cells and keratinocytes.
Methods
Formulations were prepared using soy phosphatidylcholine (SPC) and sodium cholate to enhance liposome flexibility . The thin film hydration method was employed, where SPC and sodium cholate, along with lipophilic drug (i.e., sulindac derivative) were dissolved in a mixture of chloroform and methanol to form a thin lipid film upon solvent evaporation. This film was then hydrated with phosphate buffer saline (PBS). The hydrated liposomal suspensions were passed through polycarbonate membranes with 200 nm and 100 nm pore sizes to achieve the desired liposomal size and ensure uniformity. Alternatively, traditional liposomes (TLs) with the compound were prepared without sodium cholate, to study the difference between liposomes with and without sodium cholate. Dynamic light scattering (DLS) was used to determine the size distribution of the liposomes, while the surface charge of the liposomes was measured using a zeta potential analyzer. The amount of lipophilic compound encapsulated within the liposomes was quantified using UV-visible spectrophotometry at the wavelength of 434 nm. In vitro drug release studies were conducted using a dialysis method to evaluate the release profile of the compound from the liposomes over a 5 h period at 37 °C in PBS with 10% ethanol, which was used to solubilize the sulindac derivative. For the preparation of the gel, Carbopol 940 was dispersed in water and neutralized with triethanolamine. The UFL or TL liposomes were then dispersed in the gel the following day. The permeability of the lipophilic compound from the gels through Strat-M membranes was assessed at 37 °C using an in vitro Franz diffusion cell setup. Strat-M is commonly used to simulate skin in drug permeability studies . The receptor medium contained PBS with 10% ethanol. Cell viability assays were used to determine the sensitivity of human melanoma cancer cells (i.e., SK-MEL-2, SK-MEL-28, Malme-3M, WM852 and A375) and human keratinocytes to encapsulated and free ADT-007.
Results
DLS measurements showed that the UFLs containing the sulindac derivative had a size of 133.1 ± 2.1 nm, a polydispersity index (PDI) of 0.13 ± 0.01, and zeta potential of -15.0 ± 2.1 mV. The TL version of this formulation had a size of 252.7 ± 3.8 nm, a PDI of 0.27 ± 0.01, and a zeta potential of -2.2 ± 0.6 mV. UFLs had an encapsulation efficiency of 83.6 ± 1.2%, and TLs had an encapsulation efficiency of 78.1 ± 0.9%. In vitro release studies in PBS with 10% ethanol at 37 °C showed a 37.2% release of cargo from UFLs after 60 minutes. The UFLs released 74.1% of its cargo after 5 h. The TLs released 28.5% after 60 minutes and 62.1% after 5 h.
Studies performed with the final gel formulation and Strat-M membranes at 37 °C showed enhanced permeability of ADT-007 when delivered in UFLs. UFLs allowed for sustained permeability over a 2 h period, and reached 96.0%. TLs, in contrast, allowed for a more gradual permeability and achieved 88.3%. This suggests that UFLs allow for a quicker and more enhanced permeation, compared to TLs. Previous studies conducted using lidocaine as the lipophilic cargo demonstrated similar results. Efficacy studies confirmed ADT-007's ability to inhibit melanoma cancer cell proliferation.
Conclusion
UFLs present a potentially superior alternative to TL in topical drug delivery. The UFLs evaluated here and in the literature [4] show that UFLs enhance permeability of lipophilic drugs through skin-like membranes, which have been shown to be comparable to human skin [3]. This enhanced permeability is due to the greater flexibility of the liposome membrane, allowed for by the addition of sodium cholate. Furthermore, both blank UFLs and TLs were previously shown to be biocompatible [4], further supporting UFLs as a versatile and effective drug delivery system. Thus, UFLs offer a promising alternative to TL for various topical therapeutic applications, and may enhance patient outcomes.
Presentation 5
A Novel Excipient-Based Solid Oral Dosage Form: Formulation, Characterization and Prediction of Clinical Outcomes
Zia Uddin Masum, St. John's University, [email protected]
Purpose
Biosustane SAIB NF, a highly hydrophobic excipient, is FDA-approved for injectable bupivacaine (POSIMIR). Biosustane is a multi-functional excipient capable of providing applications in solubility enhancement, mucoadhesive, and sustained release. Despite its high viscosity and stickiness presenting processing challenges, Biosustane presents a great opportunity to be developed as an excipient for oral delivery. We propose to develop Biosustane-enabled clinically relevant oral solid dosage forms of carbamazepine (CBZ), a BCS Class II drug. This study was focused on exploring the potential of establishing Biosustane as a one-stop excipient for oral formulations.
Methods
Biosustane SAIB NF granules were prepared using ethanol and DCM solvents through two distinct processes, followed by solvent evaporation. The granules were evaluated for flowability via the Carr Index, Hausner ratio, and angle of repose. Physiochemical characterization was performed using various techniques, including DSC, XRD, TGA, and NMR. Tablets and capsules were formulated and assessed accordingly. In-vitro dissolution was conducted, and stability studies were performed following the ICH guidance. An IVIVC model was developed using the innovator CR product dissolution and respective in-vivo clinical data with Gastroplus 9.9, the model validation meeting FDA IVIVC guidance.
Results
Based on flowability characterization, FD22%, and FE13% granules were selected for DSC, XRD, TGA, and NMR analysis, revealing that the formulation was more amorphous than the pure drug. Granules were suitable for tablet (100 mg CBZ) and capsule (50 mg CBZ) preparation. Dissolution studies showed more sustained release in tablets than in capsules.
The IVIVC model indicated that the small intestine and colon were responsible for drug absorption, with the colon showing enhanced absorption due to slower dissolution and longer residence time. FD22% capsules showed 69.9% absorption, while tablets showed 26.8%. For FE13%, capsules absorbed 65.5% and tablets 24.5%. Predicted Cmax and AUC for FD22% capsules were 0.295 ug/mL and 19.31 ug-h/mL, respectively, while tablets had 0.196 ug/mL and 14.84 ug-h/mL. FE13% capsules had 0.272 ug/mL and 18.08 ug-h/mL, and tablets 0.189 ug/mL and 13.49 ug-h/mL.
Conclusion
Solid oral dosages with Biosustane SAIB NF were formulated, and IVIVC was established, predicting human pharmacokinetic parameters, which provided insightful information for further formulation optimization.
Presentation 6
Prediction of surfactant-mediated dissolution of poorly soluble drugs from drug powder
Roshni Patel, University of Maryland Baltimore, [email protected]
Purpose
Beyond rough “what if” estimation, in vitro dissolution is infrequently predicted. The objective was to assess the predictability of a powder dissolution model with a single diffusion layer thickness model, where dissolution of various drugs was facilitated by several surfactant micelles. Two competing models for diffusion layer thickness: fixed thickness (i.e., hfixed) and radius-dependent thickness (i.e., hmax) model were assessed.
Methods
Powder dissolution of three poorly water-soluble drugs (i.e., posaconazole, ritonavir, and griseofulvin) was conducted into no surfactant and four surfactant media [i.e., sodium lauryl sulfate (SLS), polysorbate 80 (PS80), polyoxyethylene (10) lauryl ether (POE10), and cetyltrimethylammonium bromide (CTAB)]. Drug solubility, micelle sizing, and drug powder particle size distribution were determined. Dissolution predictions were conducted using a film dissolution model applied to spherical particles, incorporating a surfactant-mediated dissolution component. Two diffusion layer thickness models were assessed: fixed thickness (hfixed) and radius-dependent thickness (hmax). Predictions were considered accurate when the predicted dissolution was within ±20% of observed values at 30 and 60 minutes. Simulations utilized the Runge-Kutta RK45 integration method, while the Radau method was applied for stiff conditions.
Results
The surfactant solutions significantly enhanced drug dissolution compared to buffer alone. The best diffusion layer thickness values for the fixed and radius-dependent models were each found to be 12 µm, with hfixed = 12 µm slightly outperforming hmax = 12 µm. Predictions using entire particle size distribution (PSD) were more accurate than those using mean particle size alone, though mean size predictions remained adequate for hfixed = 12 µm. Model credibility assessment was conducted by evaluating question of interest, context of use, and model risk, with an overall model risk categorized as medium.
Conclusion
The surfactant-mediated dissolution model successfully predicted in vitro drug dissolution of polydisperse powders in multiple surfactant solutions. The fixed diffusion layer thickness model (hfixed = 12 µm) was preferred. These findings advance in vitro dissolution modeling and provide insights into predicting dissolution in surfactant media, with potential implications for physiologically based biopharmaceutical modeling (PBBM).
Moderator: Dimple Modi
Presentation 1
PNA-mediated targeting of the oncogenic miRNA 17-92 cluster
Ivy Browne, University of Saint Joseph, [email protected]
Purpose
RNA therapeutics has made remarkable progress in recent years with the FDA approval of RNA targeting drugs. MicroRNAs (miRs) occupy a central position in RNA therapeutics. MiRs are 21-25 nucleotides long non-coding RNAs that regulate gene expression by binding to mRNAs. A 6-9 nucleotide long seed region of a miR binds with 3’-UTR of a mRNA, allowing a single miR to regulate the expression of several mRNAs. Different miRs share a common seed region. An effective strategy for targeting multiple miRs is targeting the seed region with antisense molecules. The miR17-92 cluster is upregulated in several cancers, making it an ideal therapeutic target. Very few studies have employed antisense molecules to target miR 17-92 cluster. Antisense molecules targeting miR 17-92 would broaden the scope of cancer therapies. We designed cationic peptide nucleic acid (PNA) based antisense molecules to target miR 17 family. PNA is a DNA/RNA mimic in which the phosphodiester backbone is replaced with a neutral N-(2- aminoethyl) glycine backbone. PNA binds to miRs with high affinity and is resistant to enzymatic degradation. We have designed short gamma PNA probes with increased specificity and robust binding affinity. We hope our findings provide valuable insights for developing cancer therapy through miR inhibition.
Methods
We conducted biophysical characterization of PNA-miR complexes using gel shift binding assays and thermal denaturation assays to confirm the binding of designed PNAs to the target sequences and assess the PNA-miR heteroduplex's stability. We are evaluating the efficacy of PNA probes in various cancer cell lines (U2932, MCF-M, DLD1, A549) through cell viability, gene expression, and protein expression assays.
Results
We observed that all PNA probes bind to different target sequences of the miR-17 family with high affinity and stability. We confirmed the cellular uptake of fluorophore (TAMRA) conjugated PNAs using flow cytometry and confocal microscopy. Additionally, we noted a downregulation in the expression of targeted miRs in U2932 cell lines.
Conclusion
We successfully synthesized cationic PNAs targeting the seed region of the miR-17 family, demonstrating high cellular uptake and established in vitro efficacy to develop a potential cancer therapeutic.
Presentation 2
Chemically engineered nucleic acids targeting VEGFA genomic DNA for cancer therapy
Angana De, University of Connecticut, [email protected]
Purpose
In solid tumors, the tumor cells experience a deficiency in nutrients and oxygen; consequently, abnormal vasculature develops to alleviate these inadequacies. In 72% of solid tumors, Vascular Endothelial Growth Factor A (VEGFA) is upregulated, playing a pivotal role in cell proliferation, tumor growth, and angiogenesis. The upregulation of VEGFA transcription occurs through the dimerization of the Hypoxic Inducible Factor-1 (HIF-1α and HIF-1β) pathway within the hypoxic tumor microenvironment. Therefore, as a proof of concept, inhibiting the interactions between the HIF-1 dimer and the Hypoxic Responsive Element (HRE) on the VEGFA gene may impede its transcription in cancerous tissues. Consequently, the sequence-specific targeting of genomic DNA that encompasses the HRE to silence the gene could provide new avenues in cancer therapy. Our objective is to target the genomic DNA of VEGFA using next-generation gamma-modified Peptide Nucleic Acid (γPNA) conjugated with a Nuclear Localization Signal (NLS) peptide, thereby enhancing its delivery to the nucleus and therapeutic efficacy in both in vitro and xenograft mouse models of triple-negative breast cancer (TNBC).
Methods
The hypoxic responsive element (HRE) of the VEGFA gene is situated upstream of the promoter region, which plays a key role in regulating transcription. The γPNA-NLS and its scrambled control are synthesized via solid-phase chemistry and tested for their ability to invade genomic DNA at the target site in vitro, using a PCR amplicon assay across various tumor cell lines. Additionally, nuclear uptake was confirmed through microscopic analysis. To assess the efficacy of the γPNA-NLS, we conduct gene expression studies and protein analysis of VEGFA and its downstream targets. Moreover, we performed cell viability and proliferation assays to evaluate the effectiveness of targeting the HRE of VEGFA. We also analyzed survival rates in a TNBC xenograft mouse model after administering γPNA-NLS to determine its anti-tumor activity in vivo.
Results
Cell culture studies (PCR amplicon assay and microscopy) confirmed that γPNA-NLS shows nuclear uptake and targets the genomic DNA of VEGFA in TNBC, lung cancer, and cervical cancer cell lines. Gene expression and protein analysis suggested the efficacy of γPNA-NLS in downregulating VEGFA levels and its downstream targets. We established the effectiveness of γPNA-NLS in reducing cell viability and cell proliferation. Furthermore, survival analysis in the TNBC xenograft mouse model strongly indicated the anti-tumor efficacy of γPNA-NLS, demonstrating a two-fold decrease in tumor growth compared to the scramble control.
Conclusion
We have sequence specifically targeted the genomic DNA of the VEGFA using γPNA-NLS to downregulate its transcription in vitro, subsequently inhibiting tumor growth in a TNBC mouse model. The results presented in this study establish a novel platform to mitigate tumor burden by targeting the genomic DNA.
Presentation 3
CFD-DEM modelling of Suspension Mixing in Pharmaceutical Manufacturing
Saeed Najafian, University of Connecticut, [email protected]
Purpose
Mixing is a vital unit operation in the manufacturing of large and small molecules, offering benefits such as uniform composition and improved dissolution of components. Solid-liquid mixing can be categorized by particle density, encompassing the suspension of denser particles and the dispersion of floating particles with lower density. In this study, we used a coupled computational fluid dynamic (CFD) and Discrete Element Method (DEM) approach to model floating particle mixing. By integrating fluid flow equations with discrete particle interactions, this method provides a powerful tool to investigate and optimize complex multiphase flows, reducing the time, cost, and material requirements associated with experimental studies.
Methods
An Eulerian-Lagrangian approach was employed to model solid-liquid mixing, where the fluid phase is treated in a continuum framework and each particle is tracked at a discrete level. This coupled CFD-DEM technique offers valuable particle scale insights, making it well-suited for analyzing mixing and segregation. Although several researchers have applied CFD-DEM to various mixing processes, limited literature exists on modeling the floating particles. To address this gap, we developed a model using ANSYS FLUENT and ROCKY to examine the mixing and segregation behavior of drug substances in a HyPerforma mixing tank.
Results
Several simulations were performed to find out the best mesh size and structure for the model. A tetrahedron mesh, about 5 times larger than particle size was chosen. Simulations with different impeller speed, particle size and particle concentration were performed. It was observed that by increasing the impeller and particle concentration speed the drawdown and distribution of the floating particles will improve. However, by increasing the particle size, due to increase in the particle inertia the drawdown and distribution over the mixing tank was reduced.
Conclusion
The coupled CFD-DEM approach proved effective in modeling the behavior of floating particles and identifying key factors such as impeller speed, particle size, and particle concentration that influence mixing performance. By combining fluid flow equations with discrete particle dynamics, this approach delivers essential insights at the particle scale while offering a robust, scalable solution for process design and optimization. Consequently, the framework contributes to more efficient, cost-effective, and reliable pharmaceutical manufacturing.
Presentation 4
Preparation and characterization of an ultraflexible liposomal gel for transdermal delivery of a novel pan-RAS inhibitor for the treatment of melanoma cancer
Shivani A. Dave, Massachusetts College of Pharmacy, [email protected]
Purpose
Ultraflexible liposomal gels (UFLs) offer a promising approach to delivering lipophilic compounds topically . This study focuses on the preparation and characterization of UFLs designed to improve the delivery of a novel pan-RAS inhibitor, ADT-007, to treat early-stage melanoma . ADT-007 potently and selectively inhibits cancer cells with mutant or activated RAS by binding RAS in a nucleotide-free state, blocking GTP loading, and disrupting RAF and PI3K binding, thereby suppressing MAPK and AKT signaling . The efficacy of free and encapsulated ADT-007 was evaluated in human melanoma cancer cells and keratinocytes.
Methods
Formulations were prepared using soy phosphatidylcholine (SPC) and sodium cholate to enhance liposome flexibility . The thin film hydration method was employed, where SPC and sodium cholate, along with lipophilic drug (i.e., sulindac derivative) were dissolved in a mixture of chloroform and methanol to form a thin lipid film upon solvent evaporation. This film was then hydrated with phosphate buffer saline (PBS). The hydrated liposomal suspensions were passed through polycarbonate membranes with 200 nm and 100 nm pore sizes to achieve the desired liposomal size and ensure uniformity. Alternatively, traditional liposomes (TLs) with the compound were prepared without sodium cholate, to study the difference between liposomes with and without sodium cholate. Dynamic light scattering (DLS) was used to determine the size distribution of the liposomes, while the surface charge of the liposomes was measured using a zeta potential analyzer. The amount of lipophilic compound encapsulated within the liposomes was quantified using UV-visible spectrophotometry at the wavelength of 434 nm. In vitro drug release studies were conducted using a dialysis method to evaluate the release profile of the compound from the liposomes over a 5 h period at 37 °C in PBS with 10% ethanol, which was used to solubilize the sulindac derivative. For the preparation of the gel, Carbopol 940 was dispersed in water and neutralized with triethanolamine. The UFL or TL liposomes were then dispersed in the gel the following day. The permeability of the lipophilic compound from the gels through Strat-M membranes was assessed at 37 °C using an in vitro Franz diffusion cell setup. Strat-M is commonly used to simulate skin in drug permeability studies . The receptor medium contained PBS with 10% ethanol. Cell viability assays were used to determine the sensitivity of human melanoma cancer cells (i.e., SK-MEL-2, SK-MEL-28, Malme-3M, WM852 and A375) and human keratinocytes to encapsulated and free ADT-007.
Results
DLS measurements showed that the UFLs containing the sulindac derivative had a size of 133.1 ± 2.1 nm, a polydispersity index (PDI) of 0.13 ± 0.01, and zeta potential of -15.0 ± 2.1 mV. The TL version of this formulation had a size of 252.7 ± 3.8 nm, a PDI of 0.27 ± 0.01, and a zeta potential of -2.2 ± 0.6 mV. UFLs had an encapsulation efficiency of 83.6 ± 1.2%, and TLs had an encapsulation efficiency of 78.1 ± 0.9%. In vitro release studies in PBS with 10% ethanol at 37 °C showed a 37.2% release of cargo from UFLs after 60 minutes. The UFLs released 74.1% of its cargo after 5 h. The TLs released 28.5% after 60 minutes and 62.1% after 5 h.
Studies performed with the final gel formulation and Strat-M membranes at 37 °C showed enhanced permeability of ADT-007 when delivered in UFLs. UFLs allowed for sustained permeability over a 2 h period, and reached 96.0%. TLs, in contrast, allowed for a more gradual permeability and achieved 88.3%. This suggests that UFLs allow for a quicker and more enhanced permeation, compared to TLs. Previous studies conducted using lidocaine as the lipophilic cargo demonstrated similar results. Efficacy studies confirmed ADT-007's ability to inhibit melanoma cancer cell proliferation.
Conclusion
UFLs present a potentially superior alternative to TL in topical drug delivery. The UFLs evaluated here and in the literature [4] show that UFLs enhance permeability of lipophilic drugs through skin-like membranes, which have been shown to be comparable to human skin [3]. This enhanced permeability is due to the greater flexibility of the liposome membrane, allowed for by the addition of sodium cholate. Furthermore, both blank UFLs and TLs were previously shown to be biocompatible [4], further supporting UFLs as a versatile and effective drug delivery system. Thus, UFLs offer a promising alternative to TL for various topical therapeutic applications, and may enhance patient outcomes.
Presentation 5
A Novel Excipient-Based Solid Oral Dosage Form: Formulation, Characterization and Prediction of Clinical Outcomes
Zia Uddin Masum, St. John's University, [email protected]
Purpose
Biosustane SAIB NF, a highly hydrophobic excipient, is FDA-approved for injectable bupivacaine (POSIMIR). Biosustane is a multi-functional excipient capable of providing applications in solubility enhancement, mucoadhesive, and sustained release. Despite its high viscosity and stickiness presenting processing challenges, Biosustane presents a great opportunity to be developed as an excipient for oral delivery. We propose to develop Biosustane-enabled clinically relevant oral solid dosage forms of carbamazepine (CBZ), a BCS Class II drug. This study was focused on exploring the potential of establishing Biosustane as a one-stop excipient for oral formulations.
Methods
Biosustane SAIB NF granules were prepared using ethanol and DCM solvents through two distinct processes, followed by solvent evaporation. The granules were evaluated for flowability via the Carr Index, Hausner ratio, and angle of repose. Physiochemical characterization was performed using various techniques, including DSC, XRD, TGA, and NMR. Tablets and capsules were formulated and assessed accordingly. In-vitro dissolution was conducted, and stability studies were performed following the ICH guidance. An IVIVC model was developed using the innovator CR product dissolution and respective in-vivo clinical data with Gastroplus 9.9, the model validation meeting FDA IVIVC guidance.
Results
Based on flowability characterization, FD22%, and FE13% granules were selected for DSC, XRD, TGA, and NMR analysis, revealing that the formulation was more amorphous than the pure drug. Granules were suitable for tablet (100 mg CBZ) and capsule (50 mg CBZ) preparation. Dissolution studies showed more sustained release in tablets than in capsules.
The IVIVC model indicated that the small intestine and colon were responsible for drug absorption, with the colon showing enhanced absorption due to slower dissolution and longer residence time. FD22% capsules showed 69.9% absorption, while tablets showed 26.8%. For FE13%, capsules absorbed 65.5% and tablets 24.5%. Predicted Cmax and AUC for FD22% capsules were 0.295 ug/mL and 19.31 ug-h/mL, respectively, while tablets had 0.196 ug/mL and 14.84 ug-h/mL. FE13% capsules had 0.272 ug/mL and 18.08 ug-h/mL, and tablets 0.189 ug/mL and 13.49 ug-h/mL.
Conclusion
Solid oral dosages with Biosustane SAIB NF were formulated, and IVIVC was established, predicting human pharmacokinetic parameters, which provided insightful information for further formulation optimization.
Presentation 6
Prediction of surfactant-mediated dissolution of poorly soluble drugs from drug powder
Roshni Patel, University of Maryland Baltimore, [email protected]
Purpose
Beyond rough “what if” estimation, in vitro dissolution is infrequently predicted. The objective was to assess the predictability of a powder dissolution model with a single diffusion layer thickness model, where dissolution of various drugs was facilitated by several surfactant micelles. Two competing models for diffusion layer thickness: fixed thickness (i.e., hfixed) and radius-dependent thickness (i.e., hmax) model were assessed.
Methods
Powder dissolution of three poorly water-soluble drugs (i.e., posaconazole, ritonavir, and griseofulvin) was conducted into no surfactant and four surfactant media [i.e., sodium lauryl sulfate (SLS), polysorbate 80 (PS80), polyoxyethylene (10) lauryl ether (POE10), and cetyltrimethylammonium bromide (CTAB)]. Drug solubility, micelle sizing, and drug powder particle size distribution were determined. Dissolution predictions were conducted using a film dissolution model applied to spherical particles, incorporating a surfactant-mediated dissolution component. Two diffusion layer thickness models were assessed: fixed thickness (hfixed) and radius-dependent thickness (hmax). Predictions were considered accurate when the predicted dissolution was within ±20% of observed values at 30 and 60 minutes. Simulations utilized the Runge-Kutta RK45 integration method, while the Radau method was applied for stiff conditions.
Results
The surfactant solutions significantly enhanced drug dissolution compared to buffer alone. The best diffusion layer thickness values for the fixed and radius-dependent models were each found to be 12 µm, with hfixed = 12 µm slightly outperforming hmax = 12 µm. Predictions using entire particle size distribution (PSD) were more accurate than those using mean particle size alone, though mean size predictions remained adequate for hfixed = 12 µm. Model credibility assessment was conducted by evaluating question of interest, context of use, and model risk, with an overall model risk categorized as medium.
Conclusion
The surfactant-mediated dissolution model successfully predicted in vitro drug dissolution of polydisperse powders in multiple surfactant solutions. The fixed diffusion layer thickness model (hfixed = 12 µm) was preferred. These findings advance in vitro dissolution modeling and provide insights into predicting dissolution in surfactant media, with potential implications for physiologically based biopharmaceutical modeling (PBBM).
