Carbon materials as new nanovehicles in hot-melt drug deposition

Abstract

The application of commercially available carbon materials (nanotubes and porous carbons) for the preparation of drug delivery systems is studied. We used two types of carbon nanotubes (CNT) and two activated carbons as potential materials in so-called hot-melt drug deposition (HMDD). The materials were first studied using Raman spectroscopy. Paracetamol was chosen as a model drug. The performed thermal analysis, kinetics, and adsorption-desorption studies revealed that nanoaggregates are formed between carbon nanotubes. In contrast, in pores of activated carbon we do not observe this process and the drug adsorption phenomenon mechanism is simply the filling of small pores. The formation of nanoaggregates was confirmed by the results of GCMC (grand canonical Monte Carlo) simulations and the study of the surface area on nitrogen adsorption-desorption isotherms. The application of carbon nanotubes in HMDD offers the possibility of controlling the rate of drug delivery. Performed MTT tests of nanotubes and drug-loaded nanotubes show that the observed decrease in cell viability number is caused by the influence of the cytostatic properties of nanotubes-they inhibit the proliferation of cells. The carbon nanotubes studied in this paper are essentially nontoxic.

Hybrid capacitor with anthraquinone-grafted carbon as a battery-type electrode operating in a low pH aqueous salt solution

“…Sometimes, such an isotherm, referred to as pseudo-type II, illustrates the metastability of the adsorbed multilayer due to the low degree of pore curvature and non-rigidity of the aggregate structure. 40 Commonly, a similar isotherm shape has been reported for carbon nanotubes, 41 and is attributed to the volume created between their entanglement. The shape of the SC2A@AQ isotherm is comparable, yet a significantly lower amount of nitrogen is adsorbed in this grafted material, and the BET specific surface area (SSA) decreases by 84%, from S BET = 1571 m 2 g −1 ( S DFT = 1502 m 2 g −1 ) in SC2A to S BET = 255 m 2 g −1 ( S DFT = 191 m 2 g −1 ) in SC2A@AQ.…”

Polymeric Network Hierarchically Organized on Carbon Nano-onions: Block Polymerization as a Tool for the Controlled Formation of Specific Pore Diameters

“…Furthermore, the porosity of the pyrolyzed CNO–polymer hybrids ( C-5 , C-6 , and C-7 ) significantly differed from the texture of the corresponding copolymers ( C-1 and C-4 ). First, the shape of the isotherms recorded for C-5 and C-6 hybrids with the H3 hysteresis loop in the P / P 0 range from 0.8 to 1 indicated the mesoporous nature of the materials (Figure b). ,, However, the N 2 adsorption/desorption curve obtained for the C-7 sample (Figure b) showed common features with isotherms of all pyrolyzed copolymers (hysteresis loop in a wide range of P / P 0 ) and C-(5-6) (no limiting adsorption at maximum P / P 0 ).…”