Pharmaceutical Sciences
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12503/30449
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Item Ternary Pseudo-Triphasic Phase Diagram for Lipid Formulation(2021) Dulie Kom Nzia, Jeanne; Dong, XiaoweiPurpose: Lipid-based formulations are frequently studied, they improve oral bioavailability of water-insoluble drugs and constitute 40% of new drugs. A ternary pseudo-phase diagram(TPPD) is a thesaurus tool used to define specific physical compositions of a thermodynamically stable solution. The aim of this study was to construct TPPD of lipid-based formulations and identify optimum composition for drug delivery. Method: The aqueous titration experimental method was used. A lipid and surfactant components were mixed in a fixed ratio. No cosurfactant was used. The mixture was heated at 45°C. Water was used as a titer and was added in increment of 5%-10% to up to 95% of the total mixture. After equilibrium, the mixture was observed for characterization. Data were gathered on a table, showing each increment of water, the amount of each component, and the percentage of each component in the mixture. Data collected were used to build TPPD through excel. Result: Comparing one set of 3 phase diagrams(PDs), the PD(Miglyol-812, TPGS, Water) presents a larger area of clear solution(CS), a very small area of microemulsion, and a small area of emulsion. The PD(Miglyol-812, Tween 80, Water) presents a smaller area of CS, a small area of microemulsion, and a larger area of emulsion. The PD(Miglyol-812, K El, Water) presents a small area of CS, a small area of microemulsion, and a large area of emulsion. Conclusion: All PD built present stable area of emulsion and microemulsion that can be reconstituted for optimum delivery.Item Testosterone Replacement Therapy: Role in Modulating Oxidative Stress within the Entorhinal Cortex(2021) Tajani, Ammaar; Cunningham, Rebecca; Rybalchenko, Nataliya; Wilson, ElizabethPurpose: Sleep apnea affects approximately a quarter of all Americans, with a higher incidence rate among men. Cognitive impairments are commonly observed. A rat model of sleep apnea, Chronic Intermittent Hypoxia (CIH), exhibits cognitive impairments associated with oxidative stress (OS). The entorhinal cortex (ETC) region of the brain is sensitive to OS and involved in cognition. Our studies show that Testosterone Replacement Therapy (TRT) can protect against CIH-induced circulating OS. However, it is unknown what the impact of TRT is on OS in the ETC. Methods: To address if TRT mitigates OS in the ETC, banked tissue from young adult male F344BN rats were exposed to normoxia (room air) or CIH (8-minute cycles of 5 minutes of 10% O2 and 3 minutes of 21% O2). Rats were gonadally intact, gonadectomized, or gonadectomized with TRT. OS was quantified by protein analysis of calpain cleavage of Spectrin and COX2. Since astrocytes can buffer OS, we quantified a marker of astrocytes (GFAP). Kruskal-Wallis non-parametric statistics were used. Results: Our prior results showed increased circulating OS in CIH exposed rats that were mitigated by TRT. Similarly, CIH increased OS in the ETC. However, astrocytes were increased only in TRT by CIH. Conclusion: This study suggests that TRT decreased OS by increasing astrocytes in the ETC. Astrocytes can play neuroprotective roles in the brain by buffering and neutralizing free radicals that lead to OS. TRT may be useful in preventing cognitive impairment associated with sleep apnea.Item Real-time monitoring of membrane composition for liposomal drug formulations in continuous manufacturing.(2021) Rincon, Julio; Garrett, Meredith; Kastellorizios, MichailPurpose: Liposomes are lipid-based vesicles with the ability to entrap drugs. Their applications continue to benefit from advances in technology and manufacturing. When it comes to liposomes, or any nanomedicines, attributes such as membrane composition, size, and drug encapsulation are important to consistently deliver the intended performance of drug products. Newly adopted continuous manufacturing processes present challenges for real-time critical attribute analysis, as most characterization techniques employ a batch-based process. Here, we present a methodology to verify liposome membrane composition in a manner that can be implemented in continuous manufacturing process by detecting changes in surface tension. Methods: 8 capillary tubes (25 µl) were simultaneously submerged in 96 well plates. Wells were loaded with 250 µl of a Doxil-like liposome formulation at a concentration of 16 mg/ml. DSPEPEG ratios varied from 2.6%, 3.9%, 4.5%, 5.3%, 6%, 8%, 9%. Cholesterol molar ratio was kept at 38%, HSPC content varied dependent on DSPEPEG ratio. Three different protocols were evaluated: single 10-second submersion, 45 continuous submersions (500 milliseconds each), and 25 µl prefill followed by 15 submersions. Results: Rise measurements demonstrated significant surface tension differences between 5.3% and all other ratios using the prefill method. In addition, both single and multiple immersion protocols showed capillary rise hysteresis. Conclusions: Preliminary studies verify surface tension can be used to distinguish PEG variations in liposome membrane composition. Additional protocol and method development is required to reduce capillary rise hysteresis and further enable real-time monitoring of membrane composition in continuous manufacturing.Item Sorafenib loaded In-situ Self-Assembling Nanoparticle: A novel approach to increasing oral bioavailability(2021) Mans, Jaylen C.; Dong, XiaoweiPurpose: Sorafenib (SFN), a multi-kinase inhibitor, has demonstrated potent anticancer activity. However, the efficacy of orally administered SFN is limited due to its poor water solubility, leading to low absorption and bioavailability. The novel nanotechnology, In-situ Self-assembling Nanoparticles (ISNP), has shown potential to overcome low solubility in complex drug candidates. The objective of this study was to investigate ISNP nanotechnology as an approach to overcome low solubility and bioavailability of orally administered SFN. Method: SFN-ISNP granules were prepared using D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS), Miglycol-12, Aeroperl-300, and SFN powder. SFN-ISNPs were characterized by particle size, drug loading (DL), entrapment efficiency (EE%) and physical structure using DLS, HPLC, and DSC analytical methods. SFN-ISNP granules were orally administered to rats, and the SFN concentrations in blood plasma and tissues were measured using LC-MS. Results: In-vitro characterization of SFN-ISNPs resulted in particle size of 181 ± 24 nm, PDI< 0.28, DL of 8.825% ± 0.36% and EE% of >99.9%(n=4). DSC analysis indicated SFN was present in an amorphous physical state within the granule. The pharmacokinetic study results demonstrate that the ISNP nanotechnology significantly increased bioavailability. Peak plasma concentration of SFN-ISNP granules resulted in 4.5-fold increase compared to SFN powder. Biodistribution results indicate that SFN-ISNP granules significantly increased SFN distribution to tissue. Conclusion: The novel ISNP drug delivery technology is a promising innovation that has demonstrated an ability to increase drug absorption and bioavailability of orally administered SFN.Item 5-Methoxyindole-2-Carboxylic acid (MICA) as a potential caloric restriction mimetic(2021) Evans, Zachary; Yan, Liang-JunPurpose: Calorie restriction (CR), as an intervention to influence aging and disease, has been demonstrated to show an inhibitory effect on dihydrolipoamide dehydrogenase (DLD), the E3 subunit of pyruvate dehydrogenase. Elevated DLD activity has been linked with an increased generation of reactive oxygen species (ROS). Increased levels of ROS contribute to aging effects and decreased life span. Theoretically, an inhibitor of DLD would produce the same decrease in ROS as CR. Methods: Searching PubMed with keywords such as caloric restriction, dihydrolipoamide dehydrogenase, 5-methoxyindole-2-carboxylic acid, reactive oxygen species, etc. Results: 5-Methoxyindole-2-Carboxylic acid (MICA) has been shown to inhibit DLD activity which could potentially limit the level of ROS produced in the body. Conclusion: Because of this mechanism of action, we have proposed that MICA has the potential to provide, at least in part, calorie restrictive mimicry by carrying out some of the beneficial physiological effects of CR.Item Discovery of Small Molecule Slack Inhibitors for the Treatment of MMPSI: SAR Development in the Eastern Region of Hit Compound VU0606170(2021) Qunies, Alshaima'a; Mishra, Nigam; Tran, Elizabeth; Spitznagel, Brittany; Weaver, C.; Emmitte, KylePurpose: Malignant Migrating Partial Seizures of Infancy (MMPSI) is a severe form of pharmacoresistant epilepsy. Slack channels are sodium-activated potassium channels, which are critical regulators of electrical activity in the CNS. MMPSI has been linked to gain-of-function mutations of Slack channels. Our objective is to develop small molecule selective Slack inhibitors through an iterative hit optimization library synthesis approach to identify lead compounds for development into MMPSI therapeutics. Methods: Classical and state-of-the-art synthetic chemistry techniques including microwave assisted organic synthesis and flow chemistry were employed. Purification was by automated liquid chromatography. Bruker Fourier 300HD and Agilent 6230 time-of-flight LC/MS were utilized to obtain NMR and HRMS, respectively. Inhibitory activity of Slack was measured utilizing a Thallium flux assay in HEK293 cells stably expressing either WT or Slack mutants. Results: SAR studies developed around hit compound VU0606170 revealed that a 2,5-di-substitution pattern on the eastern phenyl ring was optimal for Slack activity. Compounds were identified that are selective for the A934T Slack variant versus WT. Modifications to the linker portion led to a loss of Slack activity. Lastly, in vitro DMPK studies with selected compounds revealed high clearance, high protein binding, and good permeability. Conclusion: SAR was identified for Slack activity, mutant selectivity, and DMPK properties around the eastern portion of VU0606170. These findings are presently being combined with SAR obtained from other regions of the molecule in search of compounds with improved potency and a more favorable DMPK profile.Item Microbial Natural Product Drug Discovery Through Systematic Sampling of Diverse Texas Soils(2021) Currens, Grant; Cheng, EricPurpose: To proof a concept of discovering microbial natural products through systemic sampling of diverse Texas soils by constructing and screening a pilot library of secondary metabolites produced by Texas soil-derived microbes for cytotoxicity. Methods: Secondary metabolites were extracted from soil-derived microbial isolates using methanol and ethyl acetate. These metabolites ("crude extract") were preliminarily fractionated through reversed-phase flash chromatography and screened for cytotoxicity against MIA PaCa-2, SH-SY5Y, and COLO 829 using an ATP-luciferase assay. Following further activity-guided HPLC purification, isolated active compounds were identified through methods including TOF-MS, MS/MS, NMR, and X-ray crystallography. Results: Malformin, a bicyclic pentapeptide which has been shown to elicit potent anti-cancer effects was purified and helped to validate our methodology. Subsequently, two related compounds, aspergillin PZ and trichoderone B, exhibiting anti-cancer effects were purified from Aspergillus flavipes sp.. These two compounds were enrolled in the National Cancer Institute 60 human tumor cell line anticancer drug screen (NCI60) which showed similar cytotoxic profiles and low potency at 10 µM. Though a >25% reduction in growth was seen in UACC-257, HOP-92, A498, and SNB-75. Conclusions: While a previously unidentified compound has not yet been discovered through this pilot study, bioactive secondary metabolites have been re-discovered which not only validates our methodology but also provides opportunity to address gaps in scientific understanding of previously reported compounds. Theoretically, enlarging our library size should afford new and active natural products.