Nitrendipine Nanocrystals: Its Preparation, Characterization, and In Vitro–In Vivo Evaluation

Abstract

Abstract. The present investigation was undertaken with the objective of developing a solid formulation containing nitrendipine nanocrystals for oral delivery. Nitrendipine nanocrystals were prepared using a tandem precipitation-homogenization process. Then, spray drying, a cost-effective method very popular in industrial situations, was employed to convert the nanocrystals into a solid form. The parameters of the preparation process were investigated and optimized. The optimal process was as follows: firstly, nitrendipine/acetone solution (100 mg/ml) was added to a polyvinyl alcohol solution (1 mg/ml) at 10°C, then the pre-suspension was homogenized for 20 cycles at 1,000 bar. Both differential scanning calorimetry and X-ray diffraction analysis indicated that nitrendipine was present in crystalline form. The in vitro dissolution rate of the nanocrystals was significantly increased compared with the physical mixture and commercial tablet. The in vivo testing demonstrated that the C max of the nanocrystals was approximately 15-fold and 10-fold greater than that of physical mixture and commercial tablet, respectively. In addition, the AUC 0→24 of the nanocrystals was approximately 41-fold and 10-fold greater than that of physical mixture and commercial tablet, respectively.

Evaluation of Tadalafil Nanosuspensions and Their PEG Solid Dispersion Matrices for Enhancing Its Dissolution Properties

“…However, it should be stated that although poor drug solubility in aqueous medium lowers its oral bioavailability, nanosizing does not guarantee high bioavailability (3,10). Nevertheless, in recent years, nanoparticle or nanocrystal engineering processes have become promising approaches for the enhancement of dissolution rates of poorly aqueous soluble drugs (11)(12)(13)(14)(15).…”

Fabrication and Characterization of Gliclazide Nanocrystals

“…No additional peaks are found in thermogram which indicates the absence of polymorphic changes in gliclazide nanocrystals. 19-21 …”

Enhancement of cellular uptake, transport and oral absorption of protease inhibitor saquinavir by nanocrystal formulation

“…The amorphous to crystalline transformation progressed with an increase in particle size and a change in polymorphism, causing the precipitated drug particles to develop into large particles within a few days [22][23][24] . High-pressure homogenization has been shown to convert materials from thermodynamically unstable amorphous particles into more stable crystalline nanoparticles [3,25] . As a result, SQV nanocrystals with a particle size of approximately 200 nm and a uniform particle size distribution (PDI ~0.1) were successfully prepared with the combination of anti-solvent precipitation and high-pressure homogenization.…”