Formulation strategies for achieving high delivery efficiency of thymoquinone-containing Nigella sativa extract to the colon based on oral alginate microcapsules for treatment of inflammatory bowel disease.

Nigella sativa extract (NSE) was incorporated in alginate microcapsules using aerosolisation and homogenisation methods, respectively, with the aim of delivering high concentrations of the active species, thymoquinone (TQ), directly to sites of inflammation in the colon following oral administration. Encapsulation of NSE was accomplished either by direct loading or diffusion into blank microparticles. Microcapsules in the size range 40-60 µm exhibited significantly higher NSE loading up to 42% w/w and encapsulation efficiency (EE) up to 63% when the extract was entrapped by direct encapsulation compared with 4.1 w/w loading, 6.2% EE when NSE was incorporated by diffusion loading. Sequential exposure of samples to simulated intestinal fluids (SIFs) revealed that the microcapsules suppressed NSE release in simulated gastric fluid (SGF) for 2 h and SIF for 4 h and liberated most of the NSE content (80%) in simulated colonic fluid (SCF) over 18 h. NSE released in SCF at 12 h exhibited antioxidant activity, when measured using the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) assay at levels comparable with the activity of unencapsulated extract. These findings demonstrate the potential of oral alginate microcapsules as highly efficient, targeted carriers for colonic delivery of NSE in the treatment of inflammatory bowel disease.

A new approach for treatment of precancerous lesions with curcumin solid-lipid nanoparticle-loaded gels: in vitro and clinical evaluation.

OBJECTIVE: Preparation and characterization of curcumin solid-lipid nanoparticle (CurSLN)-loaded mucoadhesive gel for local treatment of oral precancerous lesions with low dose. METHODOLOGY: The formulated CurSLNs were dispersed in a mucoadhesive gel matrix to be applied to the buccal mucosa. Conventional mucoadhesive gel using binary system was adopted. The prepared gels were evaluated for in vitro drug dialysis, ex vivo mucoadhesion test and ex vivo permeation study using chicken buccal mucosa. Short-term clinical evaluation was carried out on 10 patients suffering oral erythroplakia in terms of pain index and lesion size measurement. (1) RESULTS: The results showed that the loaded gel with CurSLN showed good mucoadhesion property and 25 min in vivo residence time. In addition to stability enhancement for the Cur powder. All formulae did not show any drug permeated, however, significant amount of Cur was retained within the chicken buccal mucosal tissue confirmed by histological examination. Significant reduction in pain, and complete healing was observed after 6 weeks of treatment. CONCLUSION: The local use of Cur in low dose is a promising option for treatment of precancerous lesions. The lack of local anti-inflammatory compounds with reduced side effects intensifies the importance of studying natural products for this purpose.

Lecithin-based nanostructured gels for skin delivery: an update on state of art and recent applications.

Conventional carriers for skin delivery encounter obstacles of drug leakage, scanty permeation and low entrapment efficiency. Phospholipid nanogels have recently been recognized as prominent delivery systems to circumvent such obstacles and impart easier application. The current review provides an overview on different types of lecithin nanostructured gels, with particular emphasis on liposomal versus microemulsion gelled systems. Liposomal gels investigated encompassed classic liposomal hydrogel, modified liposomal gels (e.g. Transferosomal, Ethosomal, Pro-liposomal and Phytosomal gels), Microgel in liposomes (M-i-L) and Vesicular phospholipid gel (VPG). Microemulsion gelled systems encompassed Lecithin microemulsion-based organogels (LMBGs), Pluronic lecithin organogels (PLOs) and Lecithin-stabilized microemulsion-based hydrogels. All systems were reviewed regarding matrix composition, state of art, characterization and updated applications. Different classes of lecithin nanogels exhibited crucial impact on transdermal delivery regarding drug permeation, drug loading and stability aspects. Future perspectives of this theme issue are discussed based on current laboratory studies.