Formulation and Characterization of Asymmetric Membrane Capsules of Cellulose AcetateAuthor(s): S. Bharath and R. H. Shobha Rani
Asymmetric membranes are commonly used in a variety of membrane separation processes such as reverse osmosis, ultrafiltration and dialysis. It consists of a relatively thin, denser outer membrane supported on a thick porous substrate. The use of asymmetric membranes as rate controlling systems are fairly new and novel. The asymmetric membrane capsule dosage form is a controlled drug delivery device that consists of a drug surrounded by a membrane, which has an asymmetric structure. The present investigation aimed for the development and evaluation of asymmetric membrane capsules of cellulose acetate, which could be used for the controlled drug delivery systems, independent of the drug core formulation and offer a major practical advantage in osmotic drug delivery systems. Asymmetric membrane capsules of cellulose acetate was prepared by wet and dry process method of phase inversion technique using a designed pilot model manual capsule shell manufacturing equipment. Characterization of the asymmetric membrane capsule shells for their physical appearance, solubility, crushing strength and surface morphology by scanning electron microscopy and UV spectroscopy were studied. The process employed for the manufacture of capsule shells was novel, industrially feasible and cost effective.