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Advances in Wet Granulation of Modern Drugs
Published in Dilip M. Parikh, Handbook of Pharmaceutical Granulation Technology, 2021
Bing Xun Tan, Wen Chin Foo, Keat Theng Chow, Rajeev Gokhale
Coaxial electrospray, also known as coaxial electrohydrodynamic atomization, is an emerging technology developed in the past decade for the encapsulation of therapeutic agents, such as drugs, proteins, and gene therapy. Utilizing an electric field, two independent coaxial liquid jets are elongated by electrical shear stress to form a Taylor cone at the nozzle tip, before breaking up into multilayer droplets, which are accelerated by a ground electrode for collection [66]. This technique allows precise control in the fabrication of core-shell particle geometry, which is advantageous for the encapsulation and protection of labile compounds such as therapeutic proteins. By convention, emulsification methods are commonly employed for encapsulation of proteins in lipid vesicles because of its relatively gentle and non-toxic conditions. However, several limitations exist with emulsification, namely low encapsulation efficiencies for water-soluble actives, and non-uniform particle size distributions. The mechanical stress involved during homogenization was reported to induce protein degradation, resulting in a loss in bioactivity. Zhang et al. prepared Ranibizumab poly (lactic-co-glycolic) acid (PLGA) microparticles using a coaxial electrospray process followed by freeze-drying for intravitreal injection and sustained drug release. The encapsulation efficiency of 70% was reported, and more importantly, the bioactivity of ranibizumab was retained above 80% at electrospray voltages below 5 kV [67].
The Small IntestineSecretions, Digestion and Motility
Published in Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal, Principles of Physiology for the Anaesthetist, 2020
Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal
The first step in fat digestion is emulsification by bile acids and lecithin. Emulsification is a process by which fat globules are broken into smaller particles by the detergent actions of bile salts and lecithin, and this increases the total surface area of the fats. The lipases are water-soluble enzymes and attack fat globules only on their surfaces. Pancreatic lipase cleaves 1-1′ ester linkages of the triglycerides to yield two monoglyceride and two free fatty acid molecules. Cholesterol esterase cleaves fatty acids from cholesterol esters, whereas phospholipase A cleaves fatty acids from phospholipids.
Specialty Silicone Conditioning Agents
Published in Randy Schueller, Perry Romanowski, Conditioning Agents for Hair and Skin, 2020
Typical properties of this class of compounds are as follows. Dimethiconol stearate. A water-insoluble, nonocclusive, highly lubricious silicone was. The physical form is a white pastelike wax, which liquiefies under pressure. It has been used in personal care applications, including dispersing of pigments such as titanium dioxide and zinc oxide for sunscreen products, and in many other applications. This is a dimethiconol-based compound.Dimethicone copolyol stearate. This material forms a microemulsion in water with no added surfactant. The product is a liquid. It is highly lubrieious and tends to stay at the interface of water and glass. The product has been used as a hair conditioner, and in a variety of emulsification applications. This is a dimethicone copolyol-based compound. To illustrate the range of solubilities achievable using this technology, products were tested at 5% solids.
The preparation and relative bioavailability of an artemisin in self-emulsifying drug delivery system
Published in Drug Delivery, 2023
Sijia Gao, Jingcai Chen, Wanqian Peng, Yang Yang, Yong Yang, Lei Hua, Yanlei Guo, Yunhong Wang, Xiaomei Zhang
In the present study, the screening range of each phase in the SEDDS was limited as follows: 20%–80% for the oil phase, 20%–80% for the surfactant, and 0%–30% for the co-surfactants. Based on the above composition ranges, different proportions of the oil phase, surfactants, and co-surfactants were weighed out and then vortexed. They were placed at room temperature for 24 h, and the occurrence of stratification was observed. The stratification ratio was then removed. Unstratified prescription of 0.5 mL was weighed out and added to 100 mL of water, and this was left at 37 ± 2 °C for magnetic stirring to observe the formation of emulsification. With the surfactants, cosurfactants, and oil phases as one side, the proportion that could form clear and transparent oil droplets without floating was determined as the effective self-emulsification region in the phase diagram, and the ternary phase diagram was drawn accordingly. The composition of the SEDDS was as follows: CS, EL, and TP. The ternary phase diagram is shown in Figure 2, with the black dots representing the test points and the area inside the black line representing the effective self-emulsification area. The results show that emulsification could be achieved within the scope of the investigation.
Overcoming hydrolytic degradation challenges in topical delivery: non-aqueous nano-emulsions
Published in Expert Opinion on Drug Delivery, 2022
Arya Kadukkattil Ramanunny, Sachin Kumar Singh, Sheetu Wadhwa, Monica Gulati, Bhupinder Kapoor, Rubiya Khursheed, Gowthamarajan Kuppusamy, Kamal Dua, Harish Dureja, Dinesh Kumar Chellappan, Niraj Kumar Jha, Piyush Kumar Gupta, Sukriti Vishwas
While preparing NANEs, generally, the lipophilic drugs are solubilized in the oil phase. Upon mixing of oil phase with surfactant-co-surfactant (Smix) and dispersion medium, emulsification process begins. During the process, the lipophilic drug stays inside the oil droplets. The oily matrix protects the encapsulated drug from the oxidation and hydrolytic degradation [91]. In case of Pickering emulsions, where the traditional surfactant is substituted with solid particles such as silica nanoparticles, clay, etc., also the drug resides in the oil matrix and solid particles accumulate at the interface of the immiscible phases. This ensures efficient stabilization of the system [92]. Schematic representation of drug encapsulation in NANEs and Pickering NANEs is shown in Figure 1.
Docetaxel-loaded PAMAM-based poly (γ-benzyl-l -glutamate)-b-d -α-tocopheryl polyethylene glycol 1000 succinate nanoparticles in human breast cancer and human cervical cancer therapy
Published in Journal of Microencapsulation, 2019
Yingting Wang, Along Zuo, Xiaoyan Huang, Ying Ying, Xinsheng Shu, Xianxiong Chen, Yatao Yang, Junxian Ma, Guimiao Lin, Xiaomei Wang, Lin Mei, Gan Liu, Yingying Zhao
In this research, a new nanocarrier PAM-PBLG-b-TPGS was synthesised and its efficacy in DTX loading therapy was determined. PAMAM poly (γ-benzyl-l-glutamic acid) (PAM-PBLG) displayed good degradability and biocompatibility of effectively loaded taxane-based drugs to produce stable Nps (Shi et al.2015). Moreover, the cytotoxicity of DTX-loaded Nps was superior to the same dose of DTX (Tang et al.2017). TPGS is a nonionic multifunctional surfactant widely used in pharmaceutical, nutraceutical and cosmetic formulations (Wang et al.2014, Ahire et al. 2018). Due to its emulsification properties, it is primarily used in the formulation of self-emulsifying drug delivery systems. This study investigated the effects of DTX-loaded TPGS-Nps on EE and antitumor effects in organisms.