Development and evaluation of physical and release properties of a tablet formulation containing dry hydroethanolic extract from Lippia alba leaves

Abstract

The development of an immediate-release solid formulation which contains natural products is a challenge considering several variables. These include the physical properties of the drug, the complex composition of the herbal extracts, and its ability to be released in the body. The present study describes the development and characterization of an immediate-release tablet formulation of a hydroethanolic extract of Lippia alba (Mill.) N. E. Br. dried leaves which possess potential gastroprotective properties and sedative effects. L. alba is a Brazilian herb known as “cidreira,” and the ethnopharmacological use of the leaf infusion has been reported in many South and Central America countries. However, no study has considered phytotherapeutics containing extracts of this herb. To achieve this goal, 14 solid formulations were produced using direct compression, wet granulation, or dry granulation. These were characterized by physical tests, such as average weight, friability, hardness, and disintegration tests. The tablet formulation produced by the dry granulation of 100 mg of the L. alba extract exhibited better physical properties, and it was characterized using acteoside (verbascoside) as a chemical marker, presenting 6.9 % w/w of acteoside content per tablet, corresponding to 41.3 mg of this constituent per unit. This formulation dissolves rapidly in simulated gastric fluid without enzymes, achieving amounts >80 % after 20 min. Thus, an immediate-release tablet formulation with L. alba extract was successfully prepared.