<?xml version="1.0" encoding="UTF-8"?><OAI-PMH xmlns="http://www.openarchives.org/OAI/2.0/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/ http://www.openarchives.org/OAI/2.0/OAI-PMH.xsd"><responseDate>2026-10-18T23:54:15Z</responseDate><request verb="GetRecord" identifier="oai:ebyu-rdlopen.rawdatalibrary.net:ebyu/12459" metadataPrefix="oai_dc">https://ebyu-rdlopen.rawdatalibrary.net/oai/request</request><GetRecord><record><header><identifier>oai:ebyu-rdlopen.rawdatalibrary.net:ebyu/12459</identifier><datestamp>2026-10-18T20:41:31Z</datestamp><setSpec>openaire</setSpec><setSpec>driver</setSpec><setSpec>com_ebyu_10000</setSpec><setSpec>col_ebyu_10001</setSpec></header><metadata><oai_dc:dc xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd"><dc:title>Preparation of nanosuspensions of a 1,4-dihydropyridine-based mixed L-/T-type calcium channel blocker by combined precipitation and ultrasonication methods</dc:title><dc:creator>Pezik, Esra</dc:creator><dc:creator>Gulsun, Tuğba</dc:creator><dc:creator>Gündüz, Miyase Gözde</dc:creator><dc:creator>Sahin, Selma</dc:creator><dc:creator>Öztürk, Naile</dc:creator><dc:creator>Vural, İmran</dc:creator><dc:subject>Equilibrium solubility</dc:subject><dc:subject>Hexahydroquinoline</dc:subject><dc:subject>Hypertension</dc:subject><dc:subject>Nanocrystals</dc:subject><dc:subject>Nanosuspension</dc:subject><dc:subject>Permeability</dc:subject><dc:subject>1,4 dihydropyridine</dc:subject><dc:subject>cryoprotective agent</dc:subject><dc:subject>deoxycholate sodium</dc:subject><dc:subject>felodipine</dc:subject><dc:subject>glucose</dc:subject><dc:subject>lacidipine</dc:subject><dc:subject>nanocrystal</dc:subject><dc:subject>nitrendipine</dc:subject><dc:subject>poloxamer</dc:subject><dc:subject>polyvinyl alcohol</dc:subject><dc:subject>sucrose</dc:subject><dc:subject>adult</dc:subject><dc:subject>animal experiment</dc:subject><dc:subject>apparent permeability</dc:subject><dc:subject>Article</dc:subject><dc:subject>controlled study</dc:subject><dc:subject>differential scanning calorimetry</dc:subject><dc:subject>drug bioavailability</dc:subject><dc:subject>drug solubility</dc:subject><dc:subject>freeze drying</dc:subject><dc:subject>high performance liquid chromatography</dc:subject><dc:subject>human</dc:subject><dc:subject>human cell</dc:subject><dc:subject>mouse</dc:subject><dc:description>M3, a condensed 1,4-dihydropyridine (DHP) derivative, targets both L- and T-type calcium channels and therefore, stands as a promising antihypertensive drug candidate. This study aims to improve the poor solubility of M3 using nanocrystal technology (a combination of precipitation and ultrasonication methods) to enhance its oral bioavailability. Pre-formulation studies were performed and M3 nanosuspensions were prepared using different stabilizers (polyvinyl pyrrolidone K30, polyvinyl alcohol, SoluPlus®) and surfactants (poloxamer 188, poloxamer 407, sodium deoxycholate, sodium lauryl sulfate) at different concentrations (0.05, 0.1, 0.5, 1.0, 2.0%, w/v). The optimum nanosuspension formulation was freeze-dried using different cryoprotectants (mannitol, trehalose, glucose, sucrose, dextran) at different ratios (1.25, 2.5, 5.0%, w/v). It was determined that the most suitable cryoprotectant and ratio was 5.0% trehalose, resulting in nanocrystals with a size of 320.2 ± 15.3 nm and a zeta potential of −27.4 ± 0.1 mV. The physicochemical properties of M3, poloxamer 188, physical mixture and freeze-dried nanocrystals were evaluated by XRD, DSC and FT-IR analyses. Characterization studies showed amorphization of M3 in the freeze-dried nanocrystals prepared with poloxamer 188. The result of equilibrium solubility and permeability studies results indicated that M3 could be a BCS class 4 compound. Cell culture studies using Caco-2 cells showed that M3 had no significant toxic effect on the cells and had a Papp value of 2.2 × 10−7 cm/s. Compared to coarse M3 powder freeze-dried M3 nanocrystals showed a 200-fold increase in solubility and a 28.6-fold increase in apparent permeability. The cytotoxic effect of M3 was also reduced by using poloxamers as stabilizers in the formulation. M3 nanosuspensions were found to be a promising candidate for the oral administration of M3 for the potential treatment of hypertension due to the increase in solubility and permeability which could enhance its oral bioavailability. © 2023 Elsevier B.V.</dc:description><dc:publisher>Editions de Sante</dc:publisher><dc:date>2023</dc:date><dc:type>Article</dc:type><dc:identifier>https://rdlopen.rawdatalibrary.net/r/ebyu/12459</dc:identifier><dc:identifier>https://doi.org/10.1016/j.jddst.2023.104772</dc:identifier><dc:identifier>1773-2247</dc:identifier><dc:language>en</dc:language><dc:relation>Journal of Drug Delivery Science and Technology</dc:relation><dc:rights>info:eu-repo/semantics/openAccess</dc:rights><dc:type>info:eu-repo/semantics/article</dc:type><dc:identifier>https://ebyu-rdlopen.rawdatalibrary.net/tr/items/ebyu/12459</dc:identifier></oai_dc:dc></metadata></record></GetRecord></OAI-PMH>