RingCap Technology Mrs. Maria Saifee Associate Professor, Pharmaceutics

INTRODUCTION RingCap is a patented, oral controlled-release drug delivery system. The dosage form is a capsule-shaped matrix tablet to which bands of insoluble material are applied circumferentially to the surface of the tablet. These bands modify the release of drug from the tablet through the control of surface area. The release of drug from RingCap tablets is proportional to the surface area exposed to the dissolution media.

This surface area changes over time as the area around the bands becomes hydrated and erodes creating new surface area. This new surface area can decrease, remain constant, or even increase with time. The exposed surface area is controlled by the number, width, and placement of bands of insoluble material applied to the tablets.

DESCRIPTION OF THE TECHNOLOGY Drug Release The RingCap system is based on the principle that the rate at which a drug is released from an erodible matrix is proportional to the surface area exposed to surrounding liquid over time.

A typical release profile for acetaminophen formulated in a conventional matrix tablet is shown

With RingCap tablets, however, new surface areas is exposed during the erosion process The specific configuration of number, width, and placement of the bands on the RingCap tablet determines the release profile.

B. Formulation and Manufacturing The matrix core tablet can be prepared by multiple techniques such as low- or high-shear wet granulation, fluid bed granulation, or dry blending. Capsule-shaped tablets are compressed using high-speed tabletting equipment. A film coat is applied to the matrix tablets to prepare the surface for the application of bands. The banding material for Ring-Cap tablets is selected from a group of polymers that are insoluble and impermeable. Conventional capsule banding equipment (modified to apply multiple bands) is employed to apply the bands around the circumference of the matrix tablets.

Technical Development Acetaminophen was selected as a model drug to challenge various parameters of the RingCap system, particularly the number, width, and placement of bands on the surface of tablets :750-mg acetaminophen matrix tablets (24.2 X 7.7 mm capsule-shaped) were used in all studies. Various band configurations were evaluated for in vitro release using a USP Type III dissolution apparatus.

REGULATORY ISSUES No anticipated regulatory barriers are associated with the RingCap system. All formulation excipients, including the banding polymer, have been previously demonstrated as acceptable for oral use. In addition, all manufacturing processes use conventional equipment commonly employed for solid oral dosage forms.

TECHNOLOGY POSITION/ COMPETITIVE ADVANTAGE Availability of a proprietary mathematical model used to predict the release of drug and shorten development time. The mathematical model enables feasibility and development studies to be accelerated by determining the necessary banding configuration for a desired drug release profile prior to the initiation of laboratory experiments.