China
Africa
Explore chapters and articles related to this topic
Chemical Permeation through Disposable Gloves
Published in Robert N. Phalen, Howard I. Maibach, Protective Gloves for Occupational Use, 2023
Glove recommendations against cytostatic drugs include double gloving and, in prolonged work, changing gloves every 30 min.8,57,61,65,68 Hands should be washed before putting on the gloves and after the handling of the cytostatic drugs. In case of glove breakage, the gloves must be immediately disposed of, the hands must be washed thoroughly, and new gloves have to be put on. It is worth noting that the bottles and packages of cytostatic drugs are often contaminated.77 Furthermore, the surfaces on which the drugs are diluted or otherwise handled may be contaminated despite careful cleaning. The handling of cytostatic drugs necessitates careful planning of the work methods and premises for which many agencies and groups continue to update.78–81 Aside from the critical procedural, engineering, administrative, and work practice controls needed when handling cytostatic drugs, greater assurance can be obtained with the use of gloves evaluated and adhering to the ATSM D 6978 standard. Lastly, it is also of importance to ensure specific permeation testing is provided for cytostatic drugs with a lower molecular weight, higher lipophilicity (LogP), and/or low hydrogen donor status.
Binders in Pharmaceutical Granulation
Published in Dilip M. Parikh, Handbook of Pharmaceutical Granulation Technology, 2021
This approach was successfully tested on four model drugs of different log P, as shown in Table 4.8. Binder solutions of varying surface tension were used to granulate the four model formulations. The studies showed that for APIs with high log P values, binders with lower surface tension, such as HPC, were indeed be more effective [47]. Conversely for very hydrophilic APIs (low log P), such as metformin HCl, polar binders such as PVP and PVP-PVA were significantly better (Figures 4.11 and 4.12).
Essential Oils as Carrier Oils
Published in K. Hüsnü Can Başer, Gerhard Buchbauer, Handbook of Essential Oils, 2020
Romana Aichinger, Gerhard Buchbauer
There are a lot of factors that affect the penetration enhancement effect of the terpenes, namely the skin type and origin to start with the treated organ. Besides the pretreatment, the vehicle system and the ingredients, their structure, concentration, and polarity, as well as pH values, are crucial. Terpenes themselves can also influence their activity as some of them—for example, menthol—are able to induce physiological reactions in the living skin, such as increase of skin temperature and vasodilatation. They also have to be suitable for the drug they enhance as polar terpenes are beneficial for hydrophilic drugs, and hydrocarbon terpenes go with lipophilic drugs. Not only the terpenes influence their effects; the drugs are co-decisive too. Drug lipophilicity is presumed to be a predominant factor affecting the skin permeability of drugs, not to forget the molecular weight, where the upper limit seems to be about 500 Da and the melting point. To get information whether a molecule is able to penetrate through the lipophilic SC barrier or not and how it can partition between the SC and hydrophilic or lipophilic vehicle, it is important to know the octanol-water partition coefficient, normally presented as logP (logarithm). The optimal logP for percutaneous penetration is in the range of 1–3, obtained by less lipophilic compounds that penetrate into the skin easily, while a logP >4 caused by highly lipophilic compounds that permeate less through the skin is not desired (Cal et al., 2005; Herman and Herman, 2014; Chen et al., 2016).
Preparation of an isorhamnetin phospholipid complex for improving solubility and anti-hyperuricemia activity
Published in Pharmaceutical Development and Technology, 2022
Fengmao Zou, Honghui Zhao, Aijinxiu Ma, Danni Song, Xiangrong Zhang, Xu Zhao
Solubility and octanol-water partition coefficient studies indicated a significant improvement in the solubility of ISO-PC and an even more significant increase in its solubility in water. Previous studies have shown that increased solubility facilitates drug absorption in the gastrointestinal tract and improves bioavailability (Saoji et al. 2017). The octanol-water partition coefficient influences the absorption, distribution, metabolism, and excretion of drugs (Han et al. 2012). In cases when the LogP is < −2.0, the high water-solubility of the drug makes it difficult to penetrate the lipid membrane. When the LogP > 3.0, the high liposolubility makes it difficult to dissolve in body fluids and remain in the biological membranes, resulting in diminished absorption. The optimal LogP value is generally considered to be in the range of −1.0–2.0, with the drug being soluble in water and lipid and then easily absorbed and transported through the membrane (Korinth et al. 2012). The formation of phospholipid complexes is an effective technique for adjusting the apparent octanol-water partition coefficient of drugs. Biswas et al. reported that the formation of phospholipid complexes reduced the octanol-water partition coefficient of piperine to 0.52 and further improved its bioavailability (Biswas et al. 2021).
Multi-targeted drug design strategies for the treatment of schizophrenia
Published in Expert Opinion on Drug Discovery, 2021
Piotr Stępnicki, Magda Kondej, Oliwia Koszła, Justyna Żuk, Agnieszka A. Kaczor
Table 1 summarizes the physicochemical properties and biological activity of the above examples of multi-target compounds. The molecular weight of most compounds except (15) compound is below 500 Da, which is beneficial for compounds exhibiting favorable pharmacokinetics after oral administration. The partition coefficient (LogP) ranges from 2.64 ± 0.51 for compound (1) to 5.90 ± 0.67 for compound (11) and is generally within tolerance for compounds with good bioavailability. The affinity between the receptor types of interest should vary by a maximum of one order of magnitude. This is observed in all of the molecules presented. A large dispersion of the affinity value is observed in relation to the anti-target receptors, which is advantageous. For example, the affinity of compound (14) for serotonin 5-HT2C and histamine H1 receptors relative to the affinity for the 5-HT2A receptor is up to four orders of magnitude lower. A large dispersion of orders of magnitude is also observed between the 5HT2C, α1A, H1 receptors for compound (11).
Synthesis, activity evaluation, and pro-apoptotic properties of novel 1,2,4-triazol-3-amine derivatives as potent anti-lung cancer agents
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2019
Xian-yu Sun, Chun-yan Zhong, Qing-qing Qiu, Zhen-wang Li, Mei-yu Liu, Xin Wang, Cheng-hao Jin
It is well known that the activity of drugs is mainly determined by their structure. One of the main factors is the lipid–water distribution coefficient (LogP value). LogP is an interpretation of the lipid phase and water phase equilibrium ratio of compounds. It can also be employed to determine pharmacological parameters. An increase in the lipid–water distribution coefficient indicates increased solubility of the compound in fat; in contrast, a decrease in this coefficient means increased solubility in water. The solubility of a compound in fatty substances present in the body is known as the hydrophobicity of that compound, whereas the solubility of a compound in water is known as hydrophilicity of that compound. The human body absorbs hydrophilic compounds more easily because of its high water content22. Nonetheless, the cell membrane has a phospholipid bilayer structure that is lipophilic in nature. Thus, if a hydrophilic component of a compound is too large, it cannot enter the cell. Therefore, anti-cancer compounds should be lipophilic to some extent. The extent of drug absorption may also be affected by the magnitude of the LogP value. Hence, an optimal LogP value is necessary to allow a material to easily enter the cell membrane and participate in biological functions. The optimal value for cLogP is approximately 523. Due to the complexity of factors affecting drug activity, a drug needs a suitable cLogP value, but an appropriate cLogP value does not guarantee a good activity. As shown in Table 1, compound 4b and BCTA seem to be two promising structures.