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Macronutrients
Published in Chuong Pham-Huy, Bruno Pham Huy, Food and Lifestyle in Health and Disease, 2022
Chuong Pham-Huy, Bruno Pham Huy
Hydrophobic or nonpolar amino acids are: Glycine (R: H), Alanine (R: CH3 –), Valine (R: (CH3)2 – CH –), Leucine (R: (CH3)2 – CH – CH2 –), Isoleucine (R: CH3 – CH2 – C(CH3)H –), Phenylalanine (R: Phenyl – CH2 –), Tryptophan (R: Indole – CH2 –), Proline (R: (HN) – CH2 – CH2 – CH2 –), Methionine (R: CH3 – S – CH2 – CH2 –) (36, 38–39).
Lutein: A Nutraceutical Nanoconjugate for Human Health
Published in Harishkumar Madhyastha, Durgesh Nandini Chauhan, Nanopharmaceuticals in Regenerative Medicine, 2022
Ishani Bhat, Bangera Sheshappa Mamatha
Mostly, encapsulation systems are emulsion-based, which have core-shelled spheroid lipid droplets distributed in an aqueous medium. Such emulsions generally contain a hydrophobic core (surfactant tails) consisting of lutein and a hydrophilic shell (surfactant head), which makes the emulsion thermodynamically stable. The suspended particles are commonly sized below 100 nm and are called microemulsions. Because hydrophobic drugs are well incorporated into such emulsions within the hydrophobic core, they are commonly used to enhance their oral bioavailability in the pharmaceutical industry. As lutein is also a hydrophobic molecule of biological significance, incorporating it into microemulsions could help improve its oral bioavailability. However, the extent of encapsulation and release from the microemulsion depends on the surfactants, co-surfactants, and oil phases used (Setya et al. 2014; Lo et al. 2016). Tween 80 is a non-ionic food-grade surfactant, which has been successfully used to prepare microemulsions of lutein and zeaxanthin and incorporated into beverages (Amar et al. 2004). A combination of Tween 80, capryol, and transcutol, used to prepare the microemulsion of Rhinacanthusnasutus carotenoid extract by sonication, encapsulated 98.6% of carotenoids (Ho et al. 2016). Besides, the microemulsion exhibited enhanced oral bioavailability (6.25%) in comparison to distilled water suspension.
Bioavailability and Granule Properties
Published in Dilip M. Parikh, Handbook of Pharmaceutical Granulation Technology, 2021
Historically, the concept of bioavailability from orally administered drugs is closely, if not exclusively, associated with dosage form performance. In particular, poor bioavailability is increasingly an issue in the drug discovery process [6]. In situations where different chemical entities are simultaneously under investigation, dosage form performance is just one of the possible contributing factors to the poor bioavailability. Other possible contributing factors may include diminished access for drug absorption due to chemical degradation, physical inactivation due to binding or complexation, microbial biotransformation, insufficient contact time in transit through the gastrointestinal tract, and poor permeability across the gastrointestinal mucosa. Drug dissolution and drug absorption processes and their consequential effects on bioavailability appear to be interdependent processes, which are influenced by the physicochemical properties of drugs, in particular for hydrophobic drugs.
Responsive nanosystems for targeted therapy of ulcerative colitis: Current practices and future perspectives
Published in Drug Delivery, 2023
Min Chen, Huanrong Lan, Ketao Jin, Yun Chen
P-glycoprotein (P-gp) is an ATP-dependent drug efflux system at the apical surface of cells and works as an efflux membrane carrier (Johnstone et al. 2000). Lipophilic substrates that cross the lipid bilayer membrane into the lumen might get removed by P-gp and returned to the external medium before they can enter the cytoplasm. Examples of hydrophobic substrates include anticancer drugs, immuno-suppressants, steroidal drugs, calcium channel blockers, beta receptor blockers and glycosidic caridiac drugs. Small intestinal epithelial cells produce p-gp at significant levels, indicating the significance of this protein in reducing the oral bioavailability of certain drugs (Gavhane and Yadav 2012). Lymphocytes, the luminal epithelium of the colon, and other barrier-functioning tissues all show P-gp that must be considered before designing a carrier system for treating UC (Cortada et al. 2009).
Efficiency of a dexamethasone nanosuspension as an intratympanic injection for acute hearing loss
Published in Drug Delivery, 2022
So-Young Jung, Subin Kim, Zion Kang, Soonmin Kwon, Juhye Lee, Joo Won Park, Kab Sig Kim, Dong-Kee Kim
Dexamethasone is widely used to treat acute hearing loss (Stachler et al., 2012). However, since dexamethasone is not very soluble in water, dexamethasone sodium phosphate (Dex-SP), which is approved for intravenous use, is used off label for intratympanic injection in patients with acute hearing loss. Among the several pathways by which drugs enter the cochlea via the middle ear, the round window membrane is the most important route (King et al., 2011). Unfortunately, little is known about the mechanism by which drugs pass through the round window membrane or what properties of drugs affect their passage through that barrier. Recently, Salt et al. (2018) reported that the lipophilicity of drugs affects their permeation of the round window membrane and that hydrophobic drugs pass through the membrane more effectively than hydrophilic drugs. The mechanism by which polyp nanoparticles (PLGA, polyp-lactic-co-glycolic acid) translocate across the round window membrane was previously reported by Zhang et al. The penetration of PLGA nanoparticles across the round window membrane via the transcellular pathway was observed by confocal laser scanning microscopy (Zhang et al., 2018). A hydrophobic drug would be advantageous, as these drugs penetrate the cell membrane when they pass through the transcellular pathway.
Current advances in biopharmaceutical informatics: guidelines, impact and challenges in the computational developability assessment of antibody therapeutics
Published in mAbs, 2022
Rahul Khetan, Robin Curtis, Charlotte M. Deane, Johannes Thorling Hadsund, Uddipan Kar, Konrad Krawczyk, Daisuke Kuroda, Sarah A. Robinson, Pietro Sormanni, Kouhei Tsumoto, Jim Warwicker, Andrew C.R. Martin
There can be opportunities to address the underlying balance of biophysical forces that drive interactions when developing models to predict the properties of biopharmaceutical candidates. Two such examples are discussed here, one relating to the measurement of hydrophobic interactions and the other to the protein structural basis of hydrophobic interaction between proteins. Several machine learning methods to predict the HIC retention time from antibody sequence input have been reported previously in the literature.33,40,129 Assessment of aggregation propensity using HIC was the best-predicted biophysical property across 12 models produced using Abpred (www.protein-sol.manchester.ac.uk/abpred), one for each of the 12 biophysical properties measured across a set of antibodies.40 Even so, there was a marked reduction in performance of the model for antibodies with higher retention times in HIC, leading to a model in which the salt gradient that is used to modulate hydrophobic interaction strength also affects interactions between charged proteins. A revised scheme was derived in which charge interactions play a role alongside hydrophobic effects in the HIC method. In this scheme, proteins with higher net charge repel more within the column when salt concentration (ionic strength) is lower, and are eluted faster, than proteins with lower net charge but the same hydrophobicity.