Maximum Swelling Index Research Articles

A Study of the Hydrophilic Cellulose Matrix: Effect of Drugs on Swelling Properties.

The swelling properties of hydrophilic cellulose matrices were studied using three drugs having different water solubility : indomethacin, theophylline, and mannitol. Two swelling parameters : maximum swelling index (V) and the apparent diffusion coefficient of water in the matrix (D w ), were calculated from the swelling data and were used to describe structures and properties of the swollen matrices. The V value indicates the swelling extent as well as the capacity of maintaining the matrix shape, whereas D w represents the swelling rate that also reflects the structural resistance of the polymer network against the movement of water molecules. The results show that both polymers and incorporated drugs influence the swelling properties of the matrices. Polymers that contain more hydroxypropoxyl group produce matrices with high integrity, even in the presence of drugs. V values indicated that the capacity of the matrices to maintain their shape depends on polymer (i.e., the swelling part). The effect of drug solubility can be seen from D w values. For a highly water-soluble drug, the structural resistance of the swollen matrices is mainly governed by the drug. In contrast, this is primarily influenced by the polymer in the case of drugs that are slightly or poorly water soluble.

A study of the hydrophilic cellulose matrix: Effect of indomethacin and a water-soluble additive on swelling properties

A swelling measurement device was designed to observe the axial swelling direction of a matrix containing various types of hydrophilic cellulose derivatives (methylcellulose, hydroxypropylmethylcellulose and hydroxypropylcellulose). The effect of indomethacin and lactose on the swelling properties was also studied. The maximum swelling index and the apparent diffusion coefficient of water in the matrix, calculated from the swelling data, were used to describe the swelling properties of the matrix, reflecting the matrix integrity. The results showed that hydroxypropylcellulose produced a matrix with a high integrity. Indomethacin and lactose changed the swelling properties of the hydrophilic cellulose matrices in this study.