Valeriana officinalis dry plant extract for direct compression: preparation and characterization

GALLO LOREANA; RAMIREZ-RIGO VERONICA; PIÑA JULIANA; PALMA SANTIAGO; ALLEMANDI DANIEL; BUCALÁ VERÓNICA

Scientia Pharmaceutica

Österreichische Apotheker-Verlagsgesellschaft

Lugar: Viena; Año: 2012

0036-8709

Valeriana officinalis L. (Valerianaceae) is one of the most used plants for the treatment of anxiety and insomnia. Usually dry plant extracts, including V. officinalis, are hygroscopic materials with poor physico-mechanical properties to be directly compressed. The global aim of this work was to obtain a V. officinalis dry extract with moderate hygroscocity and suitable for direct compression (DC) by using a simple and economical technique of mixing and oven drying. The evaluation of its pharmaceutical performance was studied through the design of tablets. The V. officinalis fluid extract was oven dried and colloidal silicon dioxide was used as drying adjuvant. The hygroscopicity and physico-mechanical properties of the V. officinalis dry extract were studied. The addition of colloidal silicon dioxide gave a dry plant extract (DPE) with good physico-mechanical properties for DC and lower hygroscopicity than the dry extract without carrier. The DPE glass transition temperature (Tg) was considerable above room temperature (about 72º C) and almost independent of relative humidity (RH) even under exposure to high humidity conditions (RH=80%). The colloidal silicon dioxide produced an antiplasticizing effect, improving the powder physically stability. The pharmaceutical performance of the developed DPE was evaluated through the design of tablet formulations by adding common excipients for DC. All the manufactured tablets showed good compactability, friability, hardness and disintegration time. Those containing a disintegrant (Avicel PH 101) exhibited the best pharmaceutical performance, being the lowest disintegration time of around 40 seconds.