Solid lipid nanoparticles (SLN) of Efavirenz as lymph targeting drug delivery system: Elucidation of mechanism of uptake using chylomicron flow blocking approach.

The aim of the present work was to develop a lymph targeted SLN formulation of antiretroviral (ARV) drug and to have an understanding of its underlying mechanism of uptake by the lymphatics. The lymphatics are the inaccessible reservoirs of HIV in human body. Efavirenz (EFV) is a BCS class II, ARV drug that undergoes extensive first pass metabolism. The EFV SLN formulation was prepared using Gelucire 44/14, Compritol 888 ATO, Lipoid S 75 and Poloxamer 188 by hot homogenization technique followed by ultrasonication method, with mean particle size of 168 nm, polydispersity index (PDI) <0.220, and mean zeta potential of -35.55 mV. DSC and XRPD studies revealed change in crystallinity index of drug when incorporated into SLN. In vitro drug release was found to be prolonged and biphasic in PBS pH 6.8. There was no significant change in the mean particle size, PDI, zeta potential and entrapment efficiency of EFV SLN after storage at 30 ± 2°C/60 ± 5%RH for two months. The results from lymphatic transport and tissue distribution study indicate that a significant part of the EFV had by-passed portal system and was recovered in the lymph via chylomicron uptake mechanism. Reduction in the amount (44.70%) of the EFV reaching to liver indicates that major amount of EFV bypasses the liver and thereby, enhances the oral bioavailability of the EFV. A significant amount of EFV was found in spleen, a major lymphatic organ. EFV SLN seems to have potential to target the ARV to lymphatics for the better management of HIV.

Makwana V ，Jain R ，Patel K ，Nivsarkar M ，Joshi A ... -  《-》

Lopinavir loaded solid lipid nanoparticles (SLN) for intestinal lymphatic targeting.

The poor orally available lopinavir was successfully encapsulated in glyceryl behenate based solid lipid nanoparticles (Lo-SLN) for its ultimate use to target intestinal lymphatic vessels in combined chemotherapy-the so-called Highly Active Anti-Retroviral Therapy (HAART). SLN with mean particle size of 230 nm (polydispersity index, PDI<0.27) and surface electrical charge of approx. -27mV, were produced by hot homogenization process followed by ultrasonication. Particles were characterized using differential scanning calorimetry (DSC), wide angle X-ray scattering (WAXS) and atomic force microscopy (AFM) to confirm their solid character and the homogeneous distribution of drug within the lipid matrix. In vitro release studies at pH 6.8 phosphate buffer (PBS) and at pH 1.2 HCl 0.1N showed a slow release in both media. From the intestinal lymphatic transport study it became evident that SLN increased the cumulative percentage dose of lopinavir secreted into the lymph, which was 4.91-fold higher when compared with a conventional drug solution in methyl cellulose 0.5% (w/v) as suspending agent (Lo-MC). The percentage bioavailability was significantly enhanced. The AUC for the Lo-SLN was 2.13-fold higher than that obtained for the Lo-MC of similar concentration. The accelerated stability studies showed that there was no significant change in the mean particle size and PDI after storage at 25±2°C/60±5% RH. The shelf life of optimized formulation was assessed based on the remained drug content in the stabilized formulation and was shown to be 21.46 months.

Aji Alex MR ，Chacko AJ ，Jose S ，Souto EB ... -  《-》

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

Siram K ，Chellan VR ，Natarajan T ，Krishnamoorthy B ，Mohamed Ebrahim HR ，Karanam V ，Muthuswamy SS ，Ranganathan HP ... -  《-》

Improved anti-hyperlipidemic activity of Rosuvastatin Calcium via lipid nanoparticles: Pharmacokinetic and pharmacodynamic evaluation.

The intent of this investigation was to improve pharmacokinetic (PK) and pharmacodynamic (PD) effects of Rosuvastatin calcium (RC) by solid lipid nanoparticles (SLNs). RC is anti-hyperlipidemic drug with low oral bioavailability (20%) due to first-pass metabolism. Hot homogenization followed by ultrasonication method was used to prepare RC-SLNs with stearic acid, glyceryl behenate and glyceryl trilaurate as lipid matrices, egg lecithin and poloxamer 188 as surfactants. The prepared SLNs were tested for particle size, PDI, zeta potential (ZP), entrapment efficiency (EE), drug content and in vitro release. Further, PK and PD studies were conducted on selected SLNs. No changes in physical stability of the optimized SLN were observed at refrigerated and room temperature for 90days. SLNs prepared with glyceryl trilaurate having average size of 67.21±1.71nm, PDI of 0.25±0.01, ZP of -28.93±0.84mV with 93.51±0.34% EE was considered as optimized. DSC and XRD studies revealed that no interaction occurred between the drug and lipid. SEM and TEM studies revealed that SLNs were nearly spherical in shape. PK studies showed improvement in the oral bioavailability (extent of absorption) of SLNs by 4.6-fold when compared to that of suspension. PD study of SLNs in hyperlipidemic rats exhibited a decrease in lipid profile for 36h, while a suspension exhibited for 24h.

Dudhipala N ，Veerabrahma K 《-》

Solid lipid nanoparticles as vesicles for oral delivery of olmesartan medoxomil: formulation, optimization and in vivo evaluation.

Nooli M ，Chella N ，Kulhari H ，Shastri NR ，Sistla R ... -  《-》