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Use of Nanocarriers to Enhance Artemisinin Activity
Published in Tariq Aftab, M. Naeem, M. Masroor, A. Khan, Artemisia annua, 2017
Artemisinin-loaded conventional liposomes and polyethylene glycol (PEGylated) liposomes were also developed. Both liposomal formulations showed more than 70% encapsulation efficacy with a mean diameter of approximately 130–140 nm. The polydispersity index of the formulations ranged from 0.2 to 0.3, and they were therefore suitable for intraperitoneal administration. The pharmacokinetic profiles and main pharmacokinetic parameters of the liposomes were evaluated in healthy mice. Free artemisinin was rapidly cleared from plasma and hardly detectable 1 h after administration. Conversely, both liposomal formulations showed much longer blood circulation time than free artemisinin; artemisinin was still detectable after 3 and 24 h of administration for conventional and PEGylated liposomes, respectively. The AUC (0–24 h) values were increased approximately six-fold in both liposomal formulations, in comparison with free artemisinin. A strong effect of formulation on the half-life of artemisinin was enhanced more than fivefold by the incorporation of PEG into liposomes. Liposomes loaded with artemisinin, especially the long-circulating vesicles, could represent a genuinely new strategy for developing smart, well-tolerated, and efficacious therapeutic nanocarriers to treat tumors, but could also be very useful to treat parasitic disease (Isacchi et al., 2011).
Polymeric Nanoparticle Preparation Methods
Published in Mesut Karahan, Synthetic Peptide Vaccine Models, 2021
Preparation of nanoparticles by the nanoprecipitation method was used by Fessi et al. This method is quick and easy, and nanoparticles are automatically formed in one step. Two immiscible solvents are required for preparation of nanoparticles. It is desired to dissolve the polymer and the active ingredient in the organic solvent. Once the polymer solution is added to the aqueous phase, it is necessary for the organic solvent be removed quickly from the medium. For encapsulation of the active substance, the polymer solution should easily diffuse into the dispersion medium. It is possible to obtain appropriate nanoparticles (100–300 nm) with a low polydispersity index. It can be worked with large group polymers such as PLGA, cellulose derivatives, and PCL in nanosphere preparation. Also, this method does not require an advanced mixing technique, sonication, or high temperature. A surfactant may not always be needed, and most importantly there is no need to use toxic organic solvent, and this technique is more suitable for hydrophobic active substances. Slightly soluble in water, 100% encapsulation efficiency can be achieved with substances dissolved in organic solvents such as ethanol and acetone. In recent years, promising results have been achieved with studies with water-soluble drugs (Çırpanlı 2009). Quérette, Fleury and Sintes-Zydowicza (2019) prepared poly(hdroxy)urethane nanoparticles DMSO solvent and SDS surfactant by the nanoprecipitation method (Quérette, Bordes, and Sintes-Zydowicz 2020). Ding et al. prepared superparamagnetic iron oxide nanoparticles in poly(methylmethacrylate) nanoparticles by the micromixer-assisted nanoprecipitation method (Ding et al. 2018). Hesperidin-diazepam-loaded PLGA nanoparticles were optimized and developed using the nanoprecipitation method (Dang et al. 2015).
Poly(Alkyl Cyanoacrylate) Nanoparticles for Delivery of Anti-Cancer Drugs
Published in Mansoor M. Amiji, Nanotechnology for Cancer Therapy, 2006
R. S. R. Murthy, L. Harivardhan Reddy
The type of degradation (bulk or surface degradation) of polymethyl-, polyethyl-, and poly(isohexyl cyanoacrylate) nanoparticles was determined using photon correlation spectroscopic measurements.48 In the case of surface degradation, the particle size should show an immediate increase while the polydispersity index remaining constant. If bulk degradation dominates, a lag period should occur, preceding the decrease in mean size due to disintegration of the particles. This process of disintegration would lead to a more heterogeneous distribution of particle sizes and consequently to an increase in the polydispersity index. Incubation of polyethyl cyanoacrylate nanoparticles with in 10−4 N NaOH led to an immediate, continuous decrease in particle size, as well as an unchanged polydispersity index indicating the predominant surface degradation. Incubation of PIHCA nanoparticles in 10−4 N NaOH led to no detectable size decrease; polydispersity was also unchanged, indicating the degradation by surface erosion at a much slower rate than poly(ethyl cyanoacrylate) nanoparticles. Coating the particles with poloxamers did not accelerate the particle degradation. At low electrolyte concentration, the size and dispersity of PIHCA nanoparticles remained unchanged during incubation in 10−4 N NaOH. At high ionic strength, the size increase of nanoparticles as a result of flocculation was larger than the size decrease due to degradation. In vitro degradation was also determined by turbidimetric measurements.55 Poly(-methyl cyanoacrylate) and poly(ethyl cyanoacrylate) nanoparticles underwent the fastest degradation. A high electrolyte concentration in the medium led to the formation of larger aggregates accompanied by an increase in absorption of dispersion. The slowly degrading polymers PIBCA and PIHCA probably release a low concentration of degradation products over a prolonged period of time, indicating their low toxicity.
Scalable flibanserin nanocrystal-based novel sublingual platform for female hypoactive sexual desire disorder: engineering, optimization adopting the desirability function approach and in vivo pharmacokinetic study
Published in Drug Delivery, 2021
Marianne J. Naguib, Amal I. A. Makhlouf
Polydispersity index is a measure of the homogeneity of particle size within the dispersed system. The smaller the dispersity index, the more uniform the system (Salah et al., 2018). The PDI of the prepared FLB-nanocrystals ranged from 0.42 ± 0.01 to 0.86 ± 0.16 (Table 2). The results came in harmony with previous research involving the preparation of nanocrystals by sono-precipitation method and got similar PDI values (Kassem et al., 2017). Similarly, Xia et al., tried to formulate nitrendipine nanocrystals using the sonication method and reported that increasing drug concentration and greater supersaturation resulted in higher crystal growth and agglomeration rate, leading to larger initial crystals with an increase in the PDI value (Xia et al., 2010). However, the ANOVA test revealed that there was a non-significant difference in PDI values between formulations (p > 0.05).
Development of polymeric nanoparticle gel prepared with the combination of ionic pre-gelation and polyelectrolyte complexation as a novel drug delivery of timolol maleate
Published in Drug Development and Industrial Pharmacy, 2020
Wildan Khairi Muhtadi, Laras Novitasari, Retno Danarti, Ronny Martien
The analysis of particle size distribution and particle size uniformity using DLS method is based on Brownian motion principle. The motion is generated by a constant collision of particles with solvent molecules that is proportional to time [34–36]. The nanoparticle formula met the requirement as a good characteristic in terms of particle size, since it possessed the particle size within the range of 10–1000 nm [6,7]. In case of the intended application of the formula as a topical dosage form, systemic drug absorption is undesired. Based on the results of other studies, the nanomaterials with particles larger than 50 nm are unable to penetrate into the deeper skin layer, even in a partially damaged skin condition. Thus, the particles are restrained and TM will be released on the skin surface [37–39]. Polydispersity index value represents the stability and uniformity of particles in the nanoparticle preparation. A wider range of particle size is indicated by higher polydispersity index values, while nanoparticle preparations with evenly sized particles possess lower polydispersity index values. The polydispersity indexes that lower than 0.7 possessed by the TMNP indicated a size uniformity of the particles within the formula [28,40].
Phospholipid–polymer hybrid nanoparticle-mediated transfollicular delivery of quercetin: prospective implement for the treatment of androgenic alopecia
Published in Drug Development and Industrial Pharmacy, 2019
Lenin Das, Monika Kaurav, Ravi Shankar Pandey
The hydrodynamic diameter, zeta potential, and polydispersity index of prepared NPs were analyzed by photon correlation spectroscopy using Zeta nano ZS (Malvern Instruments, Malvern, UK) with the dilution ratio 1:100 using distilled water pH 7.0. One milliliter NPs was added to the sample cell, each sample was measured three times and values are presented as mean ± SD. The polydispersity index (PDI) was determined as a measure of homogeneity. Shapes of NPs were examined by transmission electron microscopy (TEM). A drop of diluted NPs sample was deposited on the carbon-coated double copper grid and negatively stained using 1% w/v phosphotungstic acid at pH 5.2 as a contrasting agent and observed under electron microscope (Joel, JEM-100 CX, Holland). Viscosity and pH of optimized NP formulations were measured with the help of Viscometer (Brookfield DV-111p, Bangalore, India) with spindle LV 63 at 100 rpm and pH meter (Systronic digital pH meter 355, Ahemdabad, India).