Modern Evaluation of Liquisolid Systems with Varying Amounts of Liquid Phase Prepared Using Two Different Methods

Abstract

Liquisolid systems are an innovative dosage form used for enhancing dissolution rate and improving in vivo bioavailability of poorly soluble drugs. These formulations require specific evaluation methods for their quality assurance (e.g., evaluation of angle of slide, contact angle, or water absorption ratio). The presented study is focused on the preparation, modern in vitro testing, and evaluation of differences of liquisolid systems containing varying amounts of a drug in liquid state (polyethylene glycol 400 solution of rosuvastatin) in relation to an aluminometasilicate carrier (Neusilin US2). Liquisolid powders used for the formulation of final tablets were prepared using two different methods: simple blending and spraying of drug solution onto a carrier in fluid bed equipment. The obtained results imply that the amount of liquid phase in relation to carrier material had an effect on the hardness, friability, and disintegration of tablets, as well as their height. The use of spraying technique enhanced flow properties of the prepared mixtures, increased hardness values, decreased friability, and improved homogeneity of the final dosage form.

The effect of superdisintegrants on the properties and dissolution profiles of liquisolid tablets containing rosuvastatin

“…26 . These results confirmed conclusions of the previous study 22 , where was observed that preparation of liquisolid systems by spraying in the fluid bed equipment led to more uniform tablets in comparison to the simple blending method.…”

“…However, liquisolid system with acceptable flowing and compressible properties can be prepared only if a maximum liquid load of the carrier material is not exceeded 30 . Therefore, according to the previous study 22 , value of liquid load factor (L f ) (the weight ratio between the drug in liquid state and the carrier material) was established to 0.6 and excipient ratio (R) (the weight ratio between the carrier and the coating material) to 50 in all formulations.…”

“…The solution was sprayed onto a calculated amount of carrier Neusilin Õ US2 (magnesium aluminometasilicate) and coated with Aerosil Õ 200 (colloidal silica) to obtain a dry powder with sufficient flow properties for further processing. According to the previous study 22 , the value of liquid load factor (Lf) (the weight ratio between the drug in liquid state and the carrier material) was established to 0.6 and excipient ratio (R) (the weight ratio between the carrier and the coating material) to 50 in all formulations. The drug solution was sprayed onto Neusilin Õ US2, and the mixture was then passed through a sieve (mesh size 1 mm) and mixed in a homogenizer for 10 min with the aim to ensure homogenous distribution of the drug in liquid state throughout the whole amount of carrier material.…”

“…Its values ranged between 3.57 ± 0.13 s/100 g (K 3.5%) and 7.72 ± 0.26 s/100 g (E 2.5%). The relatively low values of flowability correspond to increased weight of Neusilin Õ US2 particles, which pores were filled with rosuvastatin solution 22 . It was proved by Gumaste et al 31 that the majority of the liquid is adsorbed into mesopores and deep into the channels of the Neusilin Õ US2's macropores.…”

“…The results of the uniformity of mass evaluation (Table 3) showed that preparation of liquisolid system by spraying in fluid bed equipment led to the formulation of powder mixtures with good flow properties and compressibility and to tablets with homogeneous weight 22 . None of the prepared liquisolid tablets deviated from the average value by more than 5% and hence met the requirement given by Ph.…”