Browsing by Author "Mans, Jaylen C."
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Item Development and Validation of a Novel RP-HPLC Analytical Method for Quantification of Amphotericin B(2022) Mans, Jaylen C.Amphotericin B (AmB) is an antifungal and antiparasitic natural product. AmB is biosynthesized through bacterial fermentation of Streptomyces nodosus. For decades researchers have been investigating new methods to improve the drug formulation. However, drug development research requires validated quantitative analysis techniques to accurately measure drug concentrations. Previously, AmB has been quantified by one of several reverse phase-high performance liquid chromatography (RP-HPLC) that have been reported in literature. However, these methods rely on relatively high disodium EDTA concentration in the mobile phase to separate AmB from its impurities. As a chelating agent, EDTA can bind to metal surfaces within HPLC instrument. Over time this effect can be detrimental, as excess EDTA can precipitate out of solution and negatively impact the integrity of internal instrument components or column performance. Further, reported RP-HPLC methods have relatively high sample run time (> 35 minutes) due to their reliance on isocratic separation. Shorter Run times (< 20 minutes) are desirable for HPLC analytical methods due to the reduced cost mobile phase, as well as to prolong lifetime of detector lamp and stationary phase column. The purpose of this work is to develop and validate a new alternative HPLC method with shorter run times that avoid high EDTA usage. Our developed method achieves a shorter run time by utilizing a gradient HPLC method and avoids the use of EDTA by replacing the agent with 0.2% Acetic Acid.Item Impact of pH modulation and NaDC micellular behavior on Amphotericin B solubility(2023) Mans, Jaylen C.Purpose: Amphotericin B (AmB) has very poor water solubility (< 1 ug/mL), resulting poor oral absorption. Thus, AmB is only commercially produced in intravenous (IV) formulations. One AmB IV formulation, Fungizone® (FZ), uses sodium deoxycholate (NaDC), a surfactant, and sodium phosphate, a pH-modifying agent, to dissolve AmB. As per instructions, the powder is dissolved in water and then diluted lower than NaDC critical micelles concentration with 5% dextrose. To understand why a low concentration NaDC could dissolve AmB, we investigated the mechanism of AmB dissolution in FZ preparation. Methods: AmB solubility in aqueous buffer solutions:Aqueous pH buffers at pH 1.2, 4.5, 6.8, 7.8, and 11 were prepared. AmB powder was mixed with pH buffers at room temperature (RT) or 37C for 24 h and processed for AmB concentration measurement via HPLC. Impact of pH on NaDC micelle formation:NaDC was mixed into pH buffer solutions at 4 mg/mL concentration and separately dissolved into pH 11 buffer at 0.08, 0.2, 0.4, 4, 10, and 20 mg/mL concentrations. The solutions were measured by Dynamic Light Scattering (DLS) to evaluate micelle formation. NaDC micelle formation in the presence of AmB at pH 11:Micelle formation in 4 mg/mL NaDC-Buffer solution was measured by DLS. Next, NaDC was mixed in pH 11 buffer, DI water, and 5% dextrose solution at 0.08, 0.2, 0.4, 4, 10, and 20 mg/mL concentrations, and measured via DLS. Additionally, AmB was mixed into NaDC media solutions at 0.1 and 5 mg/ml and measured via DLS. Enhancement of NaDC and pH 11 on AmB solubility:NaDC was dissolved in pH buffer at 4, 10, and 20 mg/mL. AmB powder then was added into the NaDC solution and mixed at RT. At 1, 12, and 24 h, samples were collected prepared for HPLC analysis. Fungizone® Preparation and Characterization:Lab FZ and commercial FZ solutions were prepared. The lab FZ solution was prepared by mixing ingredients at RT until the solution was visibly clear. Commercial FZ powder was reconstituted with DI water. FZ solutions were diluted 1:50 with filtered 5% dextrose. Following dilution, the commercial FZ was characterized via pH measurements, DLS analysis, and HPLC measurements. Results: AmB is not stable at extreme pH with heat; therefore, solubility studies were performed at RT. AmB (pKa 5.5 and 10) had the highest solubility at pH 11 (216 ug/mL). NaDC has different micellular behavior in different pH conditions, generating lower CMCs at pH 7.8 and 11. Further, pH 11 was able to increase aqueous AmB solubility in the presence of NaDC. Conclusion: Both pH 11 and NaDC can increase AmB aqueous solubility; however, pH 11 combined with NaDC can synergistically enhance AmB solubility significantly. Additionally, pH 11 facilitated stable AmB-NaDC micelles formation below NaDC critical micelle concentration in water. Thus, the initial reconstitution of FZ in water generated a high pH facilitated AmB dissolution via AmB-NaDC micelles formation. Once the micelles formed, they were stable for further dilution with 5% dextrose below the CMC of NaDC.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 The Development of Lipid-Based Sorafenib Granules to Enhance the Oral Absorption of Sorafenib(MDPI, 2023-12-23) Mans, Jaylen C.; Dong, XiaoweiSorafenib (SFN) is an anticancer multi-kinase inhibitor with great therapeutic potential. However, SFN has low aqueous solubility, which limits its oral absorption. Lipids and surfactants have the potential to improve the solubility of water-insoluble drugs. The aim of this study is thus to develop novel lipid-based SFN granules that can improve the oral absorption of SFN. SFN powder was coated with a stable binary lipid mixture and then absorbed on Aeroperl 300 to form dry SFN granules with 10% drug loading. SFN granules were stable at room temperature for at least three months. Compared to SFN powder, SFN granules significantly increased SFN release in simulated gastric fluid and simulated intestinal fluid with pancreatin. Pharmacokinetics and tissue distribution of SFN granules and SFN powder were measured following oral administration to Sprague Dawley rats. SFN granules significantly increased SFN absorption compared to SFN powder. Overall, the lipid-based SFN granules provide a promising approach to enhancing the oral absorption of SFN.