China
Africa
Explore chapters and articles related to this topic
Dry-Fill Formulation and Filling Technology
Published in Larry L. Augsburger, Stephen W. Hoag, Pharmaceutical Dosage Forms, 2017
Pavan Heda, Vikas Agarwal, Shailesh K. Singh
Both the formulation and the type and conditions of the capsule-filling process can affect the packing density and liquid permeability of the capsule contents. In general, an increase in packing density (i.e., a decrease in porosity) of the encapsulated mass will probably result in a decrease in liquid permeability and dissolution rate, particularly if the drug is hydrophobic or if a hydrophilic drug is mixed with a hydrophobic lubricant such as magnesium stearate. If the encapsulated mass is tightly packed (high packing density) for a hydrophobic drug, then even with a reduction in particle size, the dissolution rate decreases, unless a surfactant is included to facilitate liquid penetration. Alternatively, wettability of poorly soluble drugs can be improved by adding a solution of a hydrophilic polymer. In this process called hydrophilization, a solution of hydrophilic polymer is spread evenly onto the drug in a high-shear mixer and the resultant granules are dried and screened before filling into capsules. Such granulations can increase the dissolution rate of a micronized hydrophobic drug by increasing the liquid permeability of the encapsulated mass.
Comparing membrane and spacer biofouling by Gram-negative Pseudomonas aeruginosa and Gram-positive Anoxybacillus sp. in forward osmosis
Published in Biofouling, 2019
Anne Bogler, Douglas Rice, Francois Perreault, Edo Bar-Zeev
Biofouling mitigation methods focusing on hindering bacterial attachment or removing biofilm from membrane and spacer were previously investigated (Yoon et al. 2013; She et al. 2016). So far, methods to prevent biofilm formation by spacer modification, such as hydrophilization of the spacer material, have only been tested in pressure-driven membrane systems, where spacer biofouling is the driving factor for feed channel pressure drop (Araújo et al. 2012; Miller et al. 2012). Although short term attachment experiments showed promising results, the modified spacers did not usually prevent biofouling in cross flow membrane cells operated over more than a few hours (Araújo et al. 2012; Miller et al. 2012). Additionally, changing the surface properties can have diverse effects on different bacterial strains, as increased hydrophilicity might only prevent attachment of hydrophobic, but not of hydrophilic cells.
Solid lipid nanoparticles: a promising tool for insulin delivery
Published in Expert Opinion on Drug Delivery, 2022
Fatemeh Mohammadpour, Hossein Kamali, Leila Gholami, Alice P. McCloskey, Prashant Kesharwani, Amirhossein Sahebkar
Chitosan, a multifunctional polymer, is characterized as a permeation enhancer with mucoadhesive characteristics [33]. In contrast to uncoated SLNs, chitosan coated SLNs avoid cellular internalization by macrophages and with prolonged blood circulation. Fluorescence microscopy, flow cytometry and uptake studies confirmed that unlike uncoated SLNs, Chitosan coated SLNs were not taken up by macrophages [66] and chitosan provides surface hydrophilization [69]. Moreover these nanoparticles for protein-based oral administration showed enhanced mucosa absorption, and good compatibility with the incorporated protein cargo and promote nanoparticle uptake by opening of tight junctions in the mucosal cell membrane responsible for drug targeting and Peyer’s patches uptake [70].
Thermo-sensitive self-assembly of poly(ethylene imine)/(phenylthio) acetic acid ion pair in surfactant solutions
Published in Drug Delivery, 2022
Figure 7(B) shows the release profile of dye loaded in IPSAM (5/5), IPSAM(5/5)/BS 100(0.1 mM), IPSAM(5/5)/CPC(0.1 mM), and IPSAM(5/5)/SLS(0.1 mM) when H2O2 concentration was 0.035%. The release degree at H2O2 concentration of 0.035% was higher than that obtained at H2O2 concentration of 0.005% (Figure 7(A,B)). For example, the maximum release degree of dye loaded in IPSAM (5/5), IPSAM(5/5)/BS 100(0.1 mM), IPSAM(5/5)/CPC(0.1 mM), and IPSAM(5/5)/SLS(0.1 mM) were about 59.5, 55, 50, and 31%, respectively, which were much higher than the corresponding maximum release degree obtained at H2O2 concentration of 0.005%. As H2O2 concentration was higher, PTA would be oxidized more extensively, the hydrophobic attraction among PEI/PTA ion pairs would be weakened more, thus the IPSAMs would be disintegrated more readily, leading to a higher release degree. There was no marked difference in the release degree among the IPSAMs except for IPSAM(5/5)/BS 100(0.1 mM) (Figure 7(B)). The IPSAMs seemed not to reflect the UCST and the thermal stability in releasing their content after being oxidized when H2O2 concentration was 0.035%. Once PTA is oxidized to some degrees (Figure 5), the oxidization-induced hydrophilization of PTA would overwhelm the lipophilization of PEI caused by the ionic surfactants, which could make no difference in the thermal stability of the IPSAMs. Meanwhile, the release degree of dye loaded in IPSAM(5/5)/BS 100(0.1 mM) was exceptionally low, possibly due to the micellization of the nonionic surfactant.