The focus of the pharmaceutical research is being steadily shifted from the development of new chemical entities to novel drug delivery systems of existing drug molecules to maximize their effectiveness in terms of therapeutic action and patent protection. This is made possible by the discovery of various compatible polymers (e.g. Carbopol polymers). Local delivery of the anesthetic agent(e.g.Lidocaine)leads to higher concentration of the drug at the intended site of action using a lower dose with an associated reduction in side effects relative to systemic administration.One of the most...