Production of Irbesartan Nanocrystals by High Shear Homogenisation and Ultra-Probe Sonication for Improved Dissolution Rate.

Irbesartan (IRB) is a BCS class II drug with poorly aqueous solubility and its absorption is dissolution rate limited. In the present study solubility and dissolution rate of IRB were improved by nanonization and using two poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) amphiphiles, namely Pluronic® F127 and Pluronic® F68, as nanosuspension stabilisers. In addition, the role of these surfactants in the solubilization of the drug was assessed. The nanocrystals were produced by two top-down techniques- high shear homogenisation and ultra-probe sonication. The nanocrystals were characterized for particle size, size distribution and zeta potential and compared to the unprocessed drug by FTIR, thermal analysis, scanning electron microscopy, solubility and dissolution rate. IRB nanocrystals showed greater solubility and faster dissolution rate than the original drug, solubility being higher for formulations prepared with F127 than those with F68. Presence of an endothermic peak of drug in the formulation confirmed its crystalline nature, regardless of the use of two energetic methods. SEM of the nanocrystals revealed a small rod-shaped morphology and the substantial decrease of the particles size. Overall results support these nanonization techniques as a simple, cost-effective and scalable approach to improve the aqueous solubility of drugs such as IRB that are classified into Class II of the Biopharmaceutic Classification System (BCS).

Poly (ɛ-caprolactone) nanoparticles of carboplatin: Preparation, characterization and in vitro cytotoxicity evaluation in U-87 MG cell lines.

Carboplatin is a platinum based drug used in the treatment of several malignancies. Due to poor cellular uptake, generally, a larger dose of drug is administered to achieve therapeutic levels, causing harmful side-effects such as hematologic toxicity. In order to enhance the cellular uptake of carboplatin, we have developed carboplatin loaded nanoparticles using the biodegradable polymer poly (ɛ-caprolactone) (PCL). Nanoparticles ranging from the size of 23.77±1.37 to 96.73±2.79 nm with positive zeta potential and moderate entrapment efficiency (54.21±0.98%) were obtained. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) confirmed the spherical morphology and smooth surface of all nanoformulations. The concentrations of PCL and the stabilizer (DMAB) are found to play a role in determining the size and the entrapment efficiency of the nanoparticles. Drug release from nanoparticles followed a biphasic pattern with an initial burst release followed by a sustained release for 10h. Results of in vitro cellular uptake and cytotoxicity studies revealed that carboplatin in the form of PCL-nanoparticles were efficiently up taken and displayed profound cytotoxicity to U-87 MG (human glioma) cells than the free drug. Importantly, unlike the free carboplatin, carboplatin in the form of PCL nanoparticles did not present any haemolytic activity in rat erythrocytes, a major side effect of this chemotherapeutic drug. This suggests that poly (ɛ-caprolactone) nanoencapsulation of carboplatin might be an efficient approach to treat cancer, while reducing carboplatin induced haemolysis.

Solid lipid nanoparticles of diethylcarbamazine citrate for enhanced delivery to the lymphatics: in vitro and in vivo evaluation.

OBJECTIVES: The major objective is to target diethylcarbamazine citrate (DEC) to the lymphatics and to increase its retention time. The effect of various excipients on the physicochemical characteristics of the nanoparticles was also studied. MATERIALS AND METHODS: Solid lipid nanoparticles (SLNs) of DEC were prepared by ultrasonication by varying the concentrations of compritol 888 ATO, poloxamer 188 and soya lecithin. The SLNs were evaluated for size, shape, texture, surface charge, physical nature of the entrapped drug, entrapment efficiency and in vitro drug release. In vivo animal studies were carried out to estimate the pharmacokinetic parameters in blood and drug concentration in lymph after oral administration. RESULTS: The size of the spherical particles was in the range of 27.25 ± 3.43 nm to 179 ± 3.08 nm and a maximum entrapment efficiency of 68.63 ± 1.53% was observed. In vitro release studies in pH 7.4 PBS displayed a rapid release and the maximum time taken for the complete drug to release was 150 min. In vivo studies indicated an enhancement in the amount of drug that reached lymphatics when administered via SLNs. CONCLUSION: Targeting of DEC to the lymphatics is possible through SLNs and the retention time in the lymphatics can also be enhanced.