3.1 Solid lipid nanoparticles for active lungs targeting

The lungs offer a very high surface area for rapid absorption of drugs owing to high vascularization and avoidance of the first pass effect. Sometimes, targeted delivery of certain drugs to the lungs is very important not only for improving the bioavailability and therapeutic activity but also for reducing the systemic side effects [5].

To achieve a prolonged hypoglycemic effect, Liu et al. developed insulin-loaded nebulized SLNs which were administered through intrapulmonary route. The hypoglycemic effects, stability of SLN during nebulization, and deposition pattern of the drug were evaluated. SLNs exhibited excellent protective effect for insulin against degradation or leakage from nanospheres and were relatively stable during nebulization via jet nebulizer. Nebulized insulin SLNs helped in improving the bioavailability and showed significantly higher hypoglycemic effect as compared to insulin phosphate buffer solution administered through pulmonary route. Thus nebulized insulin-SLNs could be a promising DDS for the treatment of diabetes [12]. In another study Bi et al. successfully developed freeze dried insulin-SLNs suitable for intra-tracheal administration through a spray. High preservation of insulin was noticed in SLNs after spray freeze drying. They had performed in vivo studies on diabetic rat and observed a prolonged hypoglycemic effect [13].

Rifampicin (RIF) were successfully encapsulated into the SLNs that delivered RIF specifically to the alveolar macrophage (AM) with strong antimycobacterial efficacy (MIC reduced to 1/8 fold than that of the free drug). Generally, mycobacterium safely multiplies in the AM (acts as an incubator), as the mycobacterium is resistant to the biocidal mechanism of AM. The developed SLNs were more stable and the particle sizes were very much suitable for improving RIF's uptake by AMs which are particle size dependent [14]. Similarly, Rifabutin loaded SLNs significantly improved uptake of the drug by the macrophages which were demonstrated in an in vitro model [15].

Co-administration of RIF and isoniazid through SLN formulation significantly reduced (60%) degradation of RIF (from 48.81 to 12.35%) from acidic gastric pH owing to the presence of isoniazid. The developed SLNs promoted targeted delivery of drug to the brain with enhanced bioavailability and lesser side effect that could be helpful in the case of cerebral tuberculosis [16].

Significantly higher biodistribution of dexamethasone acetate (DXM) to the lungs was achieved through intravenous administration of DXM loaded SLNs. The area under curve (AUC) of DXM- SLNs was increased by 17.8-fold as compared to DXM-solution. The maximum concentration of the DXM in the lungs was observed at 0.5 h post DXM-SLNs injection [17].

Similarly higher biodistribution of amikacin (AMK) in the lungs was achieved by pulmonary administration of AMK-SLNs as compared to the free drug administered through i.v., which could be helpful in the treatment of cystic fibrosis [18].

3. Solid lipid nanoparticles for lungs targeting

Role of Novel Drug Delivery Vehicles in Nanobiomedicine

3.1 Solid lipid nanoparticles for active lungs targeting

ground.

effects [5].

in an in vitro model [15].

98

be helpful in the case of cerebral tuberculosis [16].

at 0.5 h post DXM-SLNs injection [17].

Targeted delivery of a drug to the lungs is gaining much more interest at the present time, for the treatment of lungs cancer, tuberculosis, and other airborne diseases where lungs are the primary site of action or site administration of drugs [11]. In order to get maximum therapeutic benefits from lungs delivery, a suitable DDS with appropriate physicochemical properties are necessary and SLN along with ligand conjugated SLN are the most fitted on this

The lungs offer a very high surface area for rapid absorption of drugs owing to high vascularization and avoidance of the first pass effect. Sometimes, targeted delivery of certain drugs to the lungs is very important not only for improving the bioavailability and therapeutic activity but also for reducing the systemic side

To achieve a prolonged hypoglycemic effect, Liu et al. developed insulin-loaded

Rifampicin (RIF) were successfully encapsulated into the SLNs that delivered RIF specifically to the alveolar macrophage (AM) with strong antimycobacterial efficacy (MIC reduced to 1/8 fold than that of the free drug). Generally, mycobacterium safely multiplies in the AM (acts as an incubator), as the mycobacterium is resistant to the biocidal mechanism of AM. The developed SLNs were more stable and the particle sizes were very much suitable for improving RIF's uptake by AMs which are particle size dependent [14]. Similarly, Rifabutin loaded SLNs significantly improved uptake of the drug by the macrophages which were demonstrated

Co-administration of RIF and isoniazid through SLN formulation significantly reduced (60%) degradation of RIF (from 48.81 to 12.35%) from acidic gastric pH owing to the presence of isoniazid. The developed SLNs promoted targeted delivery of drug to the brain with enhanced bioavailability and lesser side effect that could

Significantly higher biodistribution of dexamethasone acetate (DXM) to the lungs was achieved through intravenous administration of DXM loaded SLNs. The area under curve (AUC) of DXM- SLNs was increased by 17.8-fold as compared to DXM-solution. The maximum concentration of the DXM in the lungs was observed

Similarly higher biodistribution of amikacin (AMK) in the lungs was achieved by pulmonary administration of AMK-SLNs as compared to the free drug administered through i.v., which could be helpful in the treatment of cystic fibrosis [18].

nebulized SLNs which were administered through intrapulmonary route. The hypoglycemic effects, stability of SLN during nebulization, and deposition pattern of the drug were evaluated. SLNs exhibited excellent protective effect for insulin against degradation or leakage from nanospheres and were relatively stable during nebulization via jet nebulizer. Nebulized insulin SLNs helped in improving the bioavailability and showed significantly higher hypoglycemic effect as compared to insulin phosphate buffer solution administered through pulmonary route. Thus nebulized insulin-SLNs could be a promising DDS for the treatment of diabetes [12]. In another study Bi et al. successfully developed freeze dried insulin-SLNs suitable for intra-tracheal administration through a spray. High preservation of insulin was noticed in SLNs after spray freeze drying. They had performed in vivo studies on diabetic rat and observed a prolonged hypoglycemic effect [13].
