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Drug Design, Synthesis, and Development
Published in Nathan Keighley, Miraculous Medicines and the Chemistry of Drug Design, 2020
Drug absorption refers to the route or mechanism by which a drug reaches the blood supply, which is also dependent on how the drug is administered. The preferred method of administration is the oral route because it is the least intrusive, hence is used most commonly. When taken orally, the drug is delivered to the gastrointestinal tract (GIT); first entering the stomach, where it is subjected to gastric juices and hydrochloric acid. These chemicals, used to digest food, will also degrade drug molecules, so for a drug to be effective orally, it must be tolerant to these conditions.
Essential Pharmacology of Abused Drugs
Published in Frank Lynn Iber, Alcohol and Drug Abuse as Encountered in Office Practice, 2020
Many drugs are bases that ionize under acidic conditions and cannot be absorbed by diffusion. Betel nut is such a drug, so it is chewed with alkaline lime to enhance its absorption. Basic drugs ionize in the stomach and will not be absorbed until they reach the alkaline milieu of the small intestine. These drugs include opiates, amphetamines, barbiturates, and some individual members of other drug classes. The pH of the gastrointestinal tract influences the amount and rate of drug absorption.
Adrenergic Antagonists
Published in Sahab Uddin, Rashid Mamunur, Advances in Neuropharmacology, 2020
It is an antagonist of the adrenergic β receptor and is cardioselective. It does not show MSA. It produces weak bronchodilating and vasodilating action due to β2 agonism and produces a relaxation action on smooth muscle (Milne et al., 1991; Florey, 2008). It also blocks peripheral α2 receptors, promotes NO production, and inhibits oxidative stress. At β2 receptor it produces intrinsic sympathomimetic action. It lowers the BP and the rate of the heart. The adverse events include headache, fatigue, dizziness, and swollen ankles. The drug absorption is fast from gastrointestinal tract after an oral dose and there is no first pass metabolism. It is employed in treating angina and hypertension (Brunton et al., 2011; Florey, 2008). The drug has a bioavailability of 30–70% and reaches a maximum plasma concentration at 2–4 h. About 25% of given dose of the drug is protein bound. The drug is not affected by first-pass effect and excretion is majorly via feces with about 11% through the urine. For parenteral administered drug 50% excretion happens via urine and 31% through feces.
Optimized self-microemulsifying drug delivery system improves the oral bioavailability and brain delivery of coenzyme Q10
Published in Drug Delivery, 2022
Thapa Chhitij, Jo-Eun Seo, Taekwang Keum, Gyubin Noh, Santosh Bashyal, Shrawani Lamichhane, Jung Hwan Kim, Jae Heon Lee, Jee Hun Park, Jaewoong Choi, Se Hyun Song, Sangkil Lee
Drug solubilization is directly associated with the extent of drug absorption and, eventually, increases drug bioavailability. Since the solubilization study was conducted after 15 min of dispersion of SMEDDS, SGF was used as a study medium to mimic the in vivo model. The formulations were optimized in order to achieve maximum DS15 (Y2). As depicted in Table 3, formulations #8 and #14 demonstrated the highest (15.95%) and the lowest (5.12%) values, respectively. The data were statistically fitted to the cubic model (Table 4), and the following polynomial equation was obtained from the program, based on the results of the ANOVA to validate the relationship between the independent variables and DS15 (Y2):
Safety, tolerability, and pharmacokinetics of the novel pan-phosphodiesterase inhibitor ZSP1601 in healthy subjects: a double-blinded, placebo-controlled first-in-human single-dose and multiple-dose escalation and food effect study
Published in Expert Opinion on Investigational Drugs, 2021
Xiaoxue Zhu, Min Wu, Hong Wang, Haijun Li, Junjie Lin, Yun Peng, Yue Hu, Cuiyun Li, Yanhua Ding
The food effect study demonstrated that the absorption of ZSP1601 was delayed, and the overall exposure was not affected by a high-fat diet meal. Based on these findings, ZSP1601 can be taken with or without food in further clinical trials. Food intake prolonged the median Tmax from 2.5 h to 4 h without any impact on its elimination, as indicated by comparable t1/2 values. Food could affect drug absorption through several mechanisms, including delayed gastric emptying, a change in gastrointestinal pH, and biliary excretion [20]. Delayed gastric emptying could hinder the absorption of ZSP1601, which may be due to its high solubility and permeability characteristics. In addition, delayed absorption is not a clinically relevant issue because ZSP1601 is likely administered on a long-term basis.
Bortezomib-loaded lipidic-nano drug delivery systems; formulation, therapeutic efficacy, and pharmacokinetics
Published in Journal of Microencapsulation, 2021
Mohammad Mahmoudian, Hadi Valizadeh, Raimar Löbenberg, Parvin Zakeri-Milani
During the development of BTZ, it was thought that BTZ would be orally bioavailable. Adams and Stein (1996) reported good oral potency and long half-life (24 h in rat) for BTZ in the treatment of rheumatoid arthritis (Adams and Stein 1996). However, there is one more data pertaining to oral delivery of BTZ and currently, BTZ is approved for SC/IV administration. In order to oral delivery of BTZ, biopharmaceutical class (BC) of BTZ was predicted based on the intestinal permeability studies in rats. It was predicted that BTZ has low intestinal permeability and high solubility (BC III). Drug absorption is the process of drug entrance from the site of administration into the bloodstream. Based on the biopharmaceutical classification system, drug solubility, and permeability can be considered as absorption limiting factors for orally delivered drugs. Therefore, the low intestinal absorption can be considered as a rate-limiting factor for oral absorption of BTZ (Raza et al. 2017).