A molecular understanding of magnesium aluminium silicate – drug, drug – polymer, magnesium aluminium silicate – polymer nanocomposite complex interactions in modulating drug release: Towards zero order release

Abstract

This study reports the use of ITC in understanding the thermodynamics occurring for a controlled release system in which complexation has been exploited. In this study, a model drug, propranolol hydrochloride (PPN) was complexed with magnesium aluminium silicate (MAS) and these complexes were used in combination with polyethylene oxide (PEO) as a hydrophilic carrier at various concentrations to sustain the release of PPN. DSC, XRPD, ATR-FTIR and SEM/EDX were successfully used in characterising the produced complexes. 2D-SAXS data patterns for MAS and the produced complexes were shown to be symmetric and circular with the particles showing no preferred orientation at the nanometre scale. ITC studies showed differences between PPN adsorption onto MAS compared with PPN adsorption onto a MAS-PEO mixture. At both temperatures studied the binding affinity Ka was greater for the titration of PPN into the MAS-PEO mixture (5.37E+04 ± 7.54E+03 M at 25 °C and 8.63E+04 ± 6.11E+03 M at 37 °C), compared to the affinity obtained upon binding between PPN and MAS as previously reported suggesting a stronger binding with implications for the dissolution process. MAS-PPN complexes with the PEO polymer compacts displayed desired manufacturing and formulation properties for a formulator including, reduced plastic recovery therefore potentially reducing the risk of cracking/splitting and on tooling wear, controlled release of PPN at a significantly low (5 %) polymer level as well as a zero-order release profile (case II transport) using up to 50 % polymer level.

Magnesium Aluminium Silicate-Metformin Hydrochloride Complexes - The Use of Isothermal Calorimetry for Probing Clay and Drug Nanocomplexations

“…The analysis of the data in the form of double logarithmic plot of intensity (log I [a.u.]) vs. the scattering vector (log {q [nm -1 ]}) followed a straight line with no peaks or other specific features, indicate power-law scattering behaviour, similarly to the MAS powder behaviour (as described in a previously (Totea et. al.…”

“…al. characterised and demonstrated the efficiency of drugclay complexes to control the release of propranolol and diltiazem. [1], [2], [4], [6], [17] Studying complexation between a wide variety of drugs and clay is of high importance in expanding the knowledge about controlled drug delivery and its exploitation.…”

“…SAXS was used to study the morphological changes of MAS upon the formation of flocculates following the adsorption of MET onto MAS, as well as to analyse the morphological characteristics of the MAS and the formed MAS-MET complexes in the solid-state form. This was conducted as reported in Totea et al [6] Solid state analysis was performed on MAS and MAS-MET double drug loaded complexes (particle size 63-125 µm). Samples were placed in disposable borosilicate glass capillary tubes (diameter 2.0 mm) and sealed at both ends.…”

Solubility and Dissolution Enhancement of Atorvastatin Calcium using Phospholipid Solid Dispersion Technique

“…For all ATR: PC: adsorbent ratio, the order of the impact of adsorbents on improving solubility was observed to be MAS > SiO2 30nm > SiO2 15nm. This is because MAS has a multilayer of silicate resulted in a large surface area (27) .…”

Molecular Dynamics Simulation to Investigate the Effect of Al2O3 Doping and Compression on the Structural Properties of Aluminium Silicate Glass

“…Aluminium Silicate (AS2) glass plays an important role in several geochemical applications, such as low-melting glassy materials, radiation shielding materials, photonics and the electronic industry. As we know, AS2 is another multi-component oxide system with a network-forming structure [1][2][3][4][5][6][7][8][9]. Many experimental techniques such as nuclear magnetic resonance, X-ray scattering, infrared, and Raman spectroscopy [10][11][12][13][14] found evidence for structural units, such as 3-fold coordinated by O atoms and 5-and 6-fold coordinated by Si (Al) atoms that are not found in pure SiO2, unless one considers SiO2 glass at a high-pressure region.…”