Controlled Release Matrix For Pharmaceuticals

What is this patent about?

'126 is related to the field of controlled-release drug delivery, specifically oral dosage forms. The background involves improving drug delivery kinetics to enhance patient compliance, minimize side effects, and maintain desired drug concentrations in the body for extended periods. Existing controlled-release methods include coated pellets, tablets, and capsules, but there's a need for improved formulations that provide prolonged and well-regulated release.

The underlying idea behind '126 is to create a controlled-release matrix using a combination of sodium alginate, a water-swellable polymer, a digestible long-chain hydrocarbon derivative, and a divalent salt. This combination, when formed into a tablet or capsule, interacts with bodily fluids to create a gel-like matrix that slowly releases the drug over an extended period.

The claims of '126 focus on a controlled release pharmaceutical composition for oral administration, comprising a controlled release matrix. This matrix includes a pharmaceutically acceptable sodium alginate, a pharmaceutically acceptable water swellable polymer, a pharmaceutically acceptable C2-C50 edible hydrocarbon derivative having a melting point ranging from 25° C. and 90° C., and a pharmaceutically acceptable divalent salt selected from the group consisting of an iron salt, a zinc salt, a magnesium salt, an aluminum salt and a calcium salt and mixtures of any of the foregoing and a therapeutically active agent to be administered and a lubricant or lubricants suitable for forming the composition into tablets or capsules.

In practice, upon ingestion, the tablet or capsule encounters fluids in the alimentary tract. The water-swellable polymer, such as hydroxyethylcellulose, hydrates and expands. Simultaneously, the divalent salt, like calcium chloride, cross-links with the sodium alginate, forming a three-dimensional gel matrix. The long-chain hydrocarbon derivative further retards dissolution, resulting in a gradual release of the drug dispersed within the matrix.

This approach differentiates itself from prior art by combining these specific components into a single matrix. The alginate provides a gelling base, the water-swellable polymer controls hydration, the hydrocarbon derivative slows dissolution, and the divalent salt strengthens the gel structure. By adjusting the ratios of these components, the release rate of the drug can be tailored to achieve a desired therapeutic effect over a prolonged period, offering a more consistent and sustained drug delivery compared to earlier alginate-based formulations.