Supersaturation is a very useful method of enhancing the permeation of drugs across membranes such as skin, because unlike other methods, it does not interfere with the ultrastructure of the stratum corneum. Many drugs are able to form inclusion complexes with beta-cyclodextrins (beta-CDs) and this study investigates the anti-nucleating effects of these compounds on supersaturated solutions of diclofenac. The ability of various betaCDs to form inclusion complexes with diclofenac was assessed by measuring their saturated solubilities. Solutions containing hydroxypropyl beta-cyclodextrin (HPbeta-CD, with a molar substitution of 0.9) produced a 7.5-fold increase in the solubility of diclofenac, which suggested that a strong complex was formed between the two compounds. This association was characterized using differential scanning calorimetry. Permeation across silicone membranes of these saturated solutions of diclofenac in the presence of the different betaCDs produced similar flux values suggesting that the overall activity was also similar. The effect of different molar ratios of HPbeta-CD and diclofenac, and the anti-nucleating effect of HPbeta-CD (both on its own and in combination with a known anti-nucleant, hydroxypropylmethyl cellulose (HPMC)) on the diffusion of diclofenac across silicone membranes was investigated. HPbeta-CD appears to have a stabilizing effect on supersaturated solutions of diclofenac as a co-ingredient with HPMC.
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http://dx.doi.org/10.1016/s0378-5173(03)00366-1 | DOI Listing |
Polymers (Basel)
December 2024
Chemistry Department, Lomonosov Moscow State University, Leninskie Gory, 1/3, Moscow 119991, Russia.
The peculiarities of the crystal formation from supersaturated aqueous solutions of CuSO on polymer substrates were studied using X-ray diffractometry. During the crystal formation, the test solutions were irradiated with one or two counter-propagating ultrasonic beams. Test solutions were prepared using natural deionized water with a deuterium content of 157 ± 1 ppm.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China.
High-entropy alloys (HEAs) with ultrafine grained and high strength can be prepared by mechanical alloying (MA) followed by sintering. Therefore, MA, as a unique solid powder processing method, has many effects on the microstructures and mechanical properties of the sintered bulk HEAs. This work focused on the alloying behavior, morphology, and phase evolution of FeCrNiAl (x = 1.
View Article and Find Full Text PDFPharm Dev Technol
January 2025
Department of Pharmaceutics, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Madhavnagar, Manipal - 576104, Karnataka, India.
Purpose: Supersaturated formulations have been widely explored for improving the oral bioavailability of drugs by using mesoporous silica (MS) to generate supersaturation via molecular adsorption; however, this is followed by precipitation. Several precipitation inhibitors (PI) have been explored to prevent precipitation and maintain the drug in solution for a longer period. However, the combined approach of MS and PIs, the impact of MS and Silica, and the loading of high-molecular-weight neutral molecules such as Cyclosporine A (CsA) have not yet been explored.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Civil & Environmental Engineering, University of California Los Angeles (UCLA), Los Angeles, CA, USA.
Biomater Sci
January 2025
Hospital of Stomatology, Sun Yat-sen University, Guangzhou, China.
: To explore the relationship between the stability of poly(gamma-glutamic acid) (γ-PGA) dispersion systems with γ-PGA of different molecular weights (MWs) and concentrations and type I collagen mineralization. : γ-PGA was used as a noncollagenous protein (NCP) analogue to regulate the stability of supersaturated γ-PGA-stabilized amorphous calcium phosphate (PGA-ACP) solutions by changing the γ-PGA MW (2, 10, 100, 200 and 500 kDa) and concentration (400, 500 and 600 μg mL). Then, the optical density (OD) at 72 h was measured to determine the PGA-ACP solution stability.
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