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Emerging Technologies for Particle Engineering
Published in Dilip M. Parikh, Handbook of Pharmaceutical Granulation Technology, 2021
Nanosuspension is a technological tool applied mainly to unravel the problem of poor solubility and bioavailability of drugs and occasionally to improve drug safety and efficacy by altering their pharmacokinetics. It is used as an alternative approach to lipid systems, when the drug is insoluble in both aqueous and organic media. The reduced particle size of a poorly water-soluble drug to nano range enormously increases surface area leading to an increased rate of dissolution or an increase in saturation solubility due to an increased dissolution pressure. For example, the solubility and dissolution rate and consequently the bioavailability of crystalline simvastatin was increased significantly by preparation of nanosuspension employing nanoprecipitation technique at a laboratory scale [9]. A pharmaceutical nanosuspension is a biphasic liquid system in which insoluble solid drug particles of the submicron range are uniformly dispersed in an aqueous vehicle. The dosage forms are colloidal and usually stabilized using surfactants and polymers, and meant to be administered through various routes, such as oral, parenteral, topical, nasal, ocular, and more [10]. Similarly, the oral bioavailability of olmesartan Medoxomil was enhanced by improving its solubility and dissolution rate by preparing nanosuspensions [11]. Nanosuspension may also be used to improve the pharmacokinetic and pharmacodynamic profile of the drug and thus therapeutic efficacy of a drug, following oral administration. This has been illustrated in the case of atovaquone nanosuspension for improved oral delivery in the treatment of malaria [12] and the case of 1,3-dicyclohexylurea, by subcutaneous route in the treatment of hypertension [13]. Nanosuspensions are prepared to enhance the bioavailability of poorly soluble drugs by enhancing their solubility. “Nevirapine, a BCS class II, non-nucleoside reverse transcriptase inhibitor (NNRTI) with undesirable solubility and dissolution kinetics from the dosage form was formulated as nanosuspension by nano edge method which increased its solubility several times as also chemical stability” [14]. Similarly, nanocrystalline suspension of poorly soluble drug itraconazole prepared by pearl milling method was found to be promising for oral drug delivery for the treatment of fungal infection [15]. Other applications of nanosupension approach are utilized to formulate products for parenteral drug delivery [16], ocular drug delivery, [17] pulmonary drug delivery [18], CNS drug delivery [19], and enzymes delivery [20]. Junghans et al. [21] evaluated Protamine, a polycationic peptide as a potential penetration enhancer for phosphodiester antisense oligonucleotides (ODNs) and formed unique complexes in the form of nanoparticles called “Proticles”. Nanoparticle drug delivery applications in cancer treatment [22], gene therapy [23] have been reported. An excellent paper reviews the application of nanotechnology in medicine [24].
Biotin anchored nanostructured lipid carriers for targeted delivery of doxorubicin in management of mammary gland carcinoma through regulation of apoptotic modulator
Published in Journal of Liposome Research, 2020
Chandra B. Tripathi, Poonam Parashar, Malti Arya, Mahendra Singh, Jovita Kanoujia, Gaurav Kaithwas, Shubhini A. Saraf
The active NHS ester of biotin was prepared as per previous reported method (Lee and Low 1994, Bae et al.2013, Wu et al.2016). Biotin (16.13 mg), DCC (13.63 mg) and NHS (7.6 mg) (1:1:1 molar ratio) in DMSO at 50 °C, was stirred for 2 h and allowed to react overnight at room temperature. Biotin-NHS was obtained by precipitation with acetone (Supplementary Figure 1, Scheme 1). Strearic acid PEG-NH2 (ST-PEG-NH2) derivative was synthesized by dissolving stearic acid (18.79 mg) in DMSO and DCC (13.63 mg) in equimolar ratio and kept under stirring in dark for 12 h (Supplementary Figure 1, Scheme 2). Thereafter, PEG-bis-amine (231.21 mg) was added to the above solution and was stirred for 3 h to obtain primary amine terminal of stearic acid (ST-PEG-NH2). The dicyclohexylurea precipitate was filtered through glass wool and the filtrate was dried under vacuum. Further, Biotin–NHS (35.95 mg; added in excess molar amount to ST-PEG-NH2) dissolved in DMF and added to the aqueous dispersion of NLC prepared with ST-PEG-NH2 (127.27 mg) and stearic acid (1272.73 mg) (i.e. 1:10 w/w) and allowed to react overnight under stirring (Supplementary Figure 1, Scheme 3). After stirring overnight at room temperature, the product was placed in a dialysis bag (8–12 kDa MWCO) and dialyzed against distilled water for 2 h. The dialyzed product was freeze dried and stored at 4 °C for further use.
Selective heat generation in cancer cells using a combination of 808 nm laser irradiation and the folate-conjugated Fe2O3@Au nanocomplex
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2018
Mehri Mirrahimi, Vahid Hosseini, S. Kamran Kamrava, Neda Attaran, Jaber Beik, Siavash Kooranifar, Habib Ghaznavi, Ali Shakeri-Zadeh
First, as shown in Scheme 1(a), the FA N-hydroxysuccinimide (FA-NHS) active ester was synthesized using a previously reported method with a minor modification [31,32]. A solution of anhydrous DMSO and triethylamine (100:1) was stirred for 10 min. Then 0.25 g of FA was added gradually to the above mixture which was continuously stirred in the dark, and kept overnight. Later FA was mixed with 0.1 g of dicyclohexylcarbodiamide and 0.1 g of N-hydroxysuccinimide and was stirred for another 24 h. The by-product, dicyclohexylurea (DCU), was removed by filtration. DMSO and triethylamine were evaporated under vacuum. Second, for the preparation of the cysteamine-FA conjugate, vacuum-dried FA-NHS was dissolved in the mixture of DMSO and trimethylamine (2:1). Later, 0.1 g cysteamine was added to the mixture and stirred overnight. The resulting yellow solid (cysteamine-FA conjugate) was obtained by filtration and was washed with ethyl ether twice.
Development and characterization dual responsive magnetic nanocomposites for targeted drug delivery systems
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2018
Lida Ahmadkhani, Abolfazl Akbarzadeh, Mojtaba Abbasian
The synthesis of the macro PEG-RAFT agent, chain transfer agent (CTA), was performed by the esterification method. Briefly, RAFT agent (0.4 g, 1.5 mmol) and dihydroxyl PEG (2 g, 0.5 mmol) were dissolved in 35 ml of DCM in a 250 ml round bottom flask equipped with a magnetic stirrer. Then, it was placed in an ice bath (0 °C); Next, DCC (0.25 g, 1.2 mmol) and DMAP (0.015 g, 0.12 mmol) were added. After 30 min of stirring at 0 °C, the reaction temperature was increased to 25 °C. The reaction mixture stirred for 2 d. The precipitated dicyclohexylurea was separated by filtration. The mixture was concentrated by rotary evaporator and then, was precipitated into excess diethyl ether to remove the unreacted RAFT agent. PEG-RAFT agent with bright yellow colour was achieved by filtering and drying under vacuum at room temperature for 24 h (1.7 g, 85%) (Scheme 1(I)).