Investigation of Hydrogel Formation from Hydroxypropylmethylcellulose (HPMC) by NMR Spectroscopy and NMR Imaging Techniques

Abstract

NMR imaging has been used to investigate the in situ swelling behavior of 2-hydroxypropylmethylcellulose (HPMC) tablets in a sample geometry chosen for the simplicity of its diffusion behavior. Preliminary 1H NMR spectroscopy experiments were performed on equilibrated mixtures of HPMC and water. From these, the dependence of the 1H T 1 and T 2 relaxation parameters of the water protons with respect to HPMC weight percent were obtained. Further analysis of the T 2 values and 1H z-spectroscopic data revealed that as the polymer concentration was increased from 10% to 20% w/w HPMC, the polymer mobility decreased substantially. One-dimensional NMR imaging of 1H in the swelling tablet system was used to monitor the movement of water into the polymer and to calculate the T 2 parameters across the system. HPMC weight percents were calculated from these T 2 values using the previously determined calibration. HPMC distributions were determined for two tablet thicknesses. Similar swelling behavior was observed for both thicknesses at early times prior to the thinner tablet becoming completely hydrated.

MRI Studies of the Hydrodynamics in a USP 4 Dissolution Testing Cell

“…[18][19][20] Examples of using MRI in quantitative and non-invasive studies of solid dosage forms include investigating events during the dissolution process, [21][22][23][24][25] identifying relationships between dissolution and formulation parameters [26][27][28][29] and mapping of tablet porosimetry. [30][31][32][33] MRI has also been used to correlate drug release profiles with dissolution events for the tablet being examined ex situ 34 and in situ in the dissolution equipment.…”

Impact of the State of Water on the Dispersion Stability of a Skin Cream Formulation Elucidated by Magnetic Resonance Techniques

“…In general, water is classified into three states: free water, freezing interfacial or intermediate water and nonfreezing or bound water. 16,17) Free water is defined as the water with the same phase transition temperature as bulk water. Freezing interfacial water is water whose phase transition is lower than 0°C.…”

Synthesis of Carbon Dots Originated from Hydroxypropylmethyl Cellulose for Sensing Ciprofloxacin

“…Therefore, HPMC serves as a carbon resource for producing CDs that is safe and low cost. 23,24 As a broad-spectrum antibiotic agent, ciprofloxacin appeared in the 1980s. Serving as a thirdgeneration fluoroquinolone antibiotic agent, which plays a critical role in our lives, while most Gram-negative bacteria and Gram-positive bacteria have remained highly susceptible to this agent.…”