Abstract. Oral administration of antibiotics to treat dental problems mostly yields slow actions due to slow onset and hepatic "first-pass." Again, commonly used dental paints are generally washed out by saliva within few hours of application. To overcome the challenges, polymeric molds to be placed on an affected tooth (during carries and gum problems) were prepared and evaluated in vitro for sustained drug release for prolonged local action. Here, amoxicillin trihydrate and lidocaine hydrochloride were used as model drugs. Dental molds were prepared using corn zein, carbopol 934 P, gum karaya powder, and poloxamer 407 by mixing and solvent evaporation technique. Different physicochemical evaluation studies such as tooth adhesion test, surface pH, swelling index, and drug-distribution pattern were carried out. Percentage swelling varied from 56% to 93%. Average tooth adhesion strength and mean initial surface pH of the formulations were 50 g and 6.5, respectively. As assessed by scanning electron microscopy, drug distribution was uniform throughout the matrix. Cumulative percentage release of lidocaine hydrochloride and amoxicillin trihydrate in simulated saliva were 98% and 50%, respectively. In vitro drug-release studies revealed the sustained-release patterns of the drugs in simulated saliva at least for 24 h. The stability study shows that the drugs were stable in the formulations following the conditions as per ICH guideline. The formulation is a novel approach to deliver the drug(s) for a prolonged period for local action upon its application on an affected tooth.

Toothache is a serious problem worldwide. To give relief from this intolerable toothache, doctors prescribe painkillers along with antibiotics. Most of the painkillers, if not all, produce hyperacidity and gastric irritation upon oral administration. Oral antibiotics have slow onset of action and undergo hepatic "first-pass" effect. Moreover, available dental formulations are mostly liquid and last only few hours upon application, before being washed out by saliva. To overcome the above-mentioned problems, a soft polymeric mold containing antibiotic and analgesic drugs and having an appropriate consistency to adhere to the tooth, was developed for sustained drug release to provide better relief in dental patients. Eudragit L 100-55, carbopol 971 P, gum karaya powder and ethyl cellulose were used to prepare the mold "Denticaps" containing Lidocaine hydrochloride and Amoxicillin trihydrate individually and in combination, by mixing and solvent evaporation technique. Different physicochemical characterization studies such as mucoadhesion test, water absorption capacity and swelling index were carried out. In vitro drug release studies showed sustained release of Lidocaine hydrochloride and Amoxicillin trihydrate in simulated saliva for 24 h. Further studies are warranted to succeed with these formulations in humans. Upon success, this type of dosage form may open up new avenues towards dentistry.

No abstract