Liquid crystals and emulsions in the formulation of drug carriers

Nose to brain delivery of mirtazapine via lipid nanocapsules: Preparation, statistical optimization, radiolabeling, in vivo biodistribution and pharmacokinetic study

Mirtazapine (MZPc) is an antidepressant drug which is approved by the FDA. It has low bioavailability, which is only 50%, in spite of its rapid absorption when orally administered owing to high first-pass metabolism. This study was oriented towards delivering intranasal (IN) mirtazapine by a direct route to the brain by means of preparing lipid nanocapsules (LNCs) as a targeted drug delivery system. MZP-LNCs were constructed by solvent-free phase inversion temperature technique applying D-Optimal mixture design to study the impact of 3 formulation variables on the characterization of the formulated nanocapsules. Independent variables were percentage of Labrafac oil, percentage of Solutol and percentage of water. Dependent variables were particle size, polydispersity index (PDI), Zeta potential and solubilization capacity. Nanocapsules of the optimized formula loaded with MZP were of spherical shape as confirmed by transmission electron microscopy with particle diameter of 20.59 nm, zeta potential of - 5.71, PDI of 0.223 and solubilization capacity of 7.21 mg/g. The in vivo pharmacokinetic behavior of intranasal MZP-LNCs in brain and blood was correlated to MZP solution after intravenous (IV) and intranasal administration in mice. In vivo biodistribution of the drug in mice was assessed by a radiolabeling technique using radioiodinated mirtazapine (131I-MZP). Results showed that intranasal MZP-LNCs were able to deliver higher amount of MZP to the brain with less drug levels in blood when compared to the MZP solution after IV and IN administration. Moreover, the percentage of drug targeting efficiency (%DTE) of the optimized MZP-LNCs was 332.2 which indicated more effective brain targeting by the intranasal route. It also had a direct transport percentage (%DTP) of 90.68 that revealed a paramount contribution of the nose to brain pathway in the drug delivery to the brain.

Intranasal lipid nanocapsules for systemic delivery of nimodipine into the brain: In vitro optimization and in vivo pharmacokinetic study

Nimodipine (NM) is FDA-approved drug for treating subarachnoid haemorrhage induced vasospasm. Intravenous (IV) administration, the most common route of NM, causes several side effects such as hypotension, bradycardia, arrhythmias and inflammation at site of administration. The aim of this study was to investigate the capability of intranasal (IN) lipid nanocapsules (LNCs) for effective delivery of NM into the brain. NM LNCs were prepared by solvent free phase inversion temperature technique using D-Optimal mixture design studying the effects of three formulation variables on the properties of the prepared LNCs. The prepared particles were evaluated for particle size, drug payload, PDI, Zeta potential and in-vitro drug release. The optimized NM loaded LNC showed particle size of 35.94 ± 0.14 nm and PDI of 0.146 ± 0.045. The in-vivo pharmacokinetic behaviour of IN NM loaded LNC in blood and brain was compared with NM-solution after IV administration in rats. Results show that IN NM loaded LNC was capable to deliver the same amount of NM at brain tissue with lower drug levels in blood compared with IV administration of the NM solution which is greatly beneficial to minimize the cardiovascular side effects of NM. Contrary to most IN nanocarriers, systemic pathway rather than olfactory pathway plays the major role in brain delivery following IN administration of LNCs. The appropriate brain delivery with lower blood levels and slow elimination propose that intranasal LNCs could provide effective systemic delivery of NM into brain with lower frequency of administration and minimal side effects.

A Clinical Anti-Ageing Comparative Study of 0.3 and 0.5% Retinol Serums: A Clinically Controlled Trial

BACKGROUND

Retinol influences the process of keratinization of the epidermis, which improves stratum corneum structure and reduces transepidermal water loss. It also significantly enhances mature skin by brightening hyperpigmentation and reducing the signs of photoageing. Cosmeceuticals are intended to both provide aesthetic effects for the skin and allow dermatological treatment. The aim of the study was to assess the rejuvenating effect of retinol serum on facial skin at concentrations of 0.3 and 0.5%, as well as any improvements in skin brightening and elasticity.

MATERIALS AND METHODS

Thirty-seven volunteers were included in the study, after confirming tolerance. The novel formula was applied once daily to the face for a period of 12 weeks: one retinol concentration on the left side and the other on the right. The initial study with liquid crystal formula (study vehicle) was carried out for 8 weeks on 28 volunteers. Treatment efficiency was evaluated at baseline, and 56 and 84 days following treatment using the multi probe adapter and Fotomedicus imaging system. PRIMOS was used to measure skin surface roughness. The visual analogue scale method enabled the results to be determined by 3 independent specialists.

RESULTS

Skin hyperpigmentation, unevenness, and wrinkles gradually decreased over the course of treatment, both on the left and right parts of the face. Adverse events were predominantly mild or moderate skin irritation. More frequent and more intense symptoms were observed on the left side (0.5%).

CONCLUSION

Retinol in liquid crystal formulation is safe and provides significant clinical benefits associated with unification of skin colour, overall skin tone, skin elasticity, and moisture. Regular use of retinol typically results in brightening of the skin and reduced signs of ageing. The objective findings confirmed the effectiveness of the procedures.

Self-sorting of deformable particles in an asynchronous logic microfluidic circuit

A microfluidic circuit can automatically sort deformable particles based on the hydrodynamic resistance that the particles induce in a constrained microfluidic channel while flowing through it.

Lipid nanocapsule-based gels for enhancement of transdermal delivery of ketorolac tromethamine

Previous reports show ineffective transdermal delivery of ketorolac by nanostructured lipid carriers (NLCs). The aim of the present work was enhancement of transdermal delivery of ketorolac by another colloidal carriers, lipid nanocapsules (LNCs). LNCs were prepared by emulsification with phase transition method and mixed in a Carbomer 934P gel base with oleic acid or propylene glycol as penetration enhancers. Permeation studies were performed by Franz diffusion cell using excised rat abdominal skin. Aerosil-induced rat paw edema model was used to investigate the in vivo performance. LNCs containing polyethylene glycol hydroxyl stearate, lecithin in Labrafac as the oily phase, and dilution of the primary emulsion with 3.5-fold volume of cold water produced the optimized nanoparticles. The 1% Carbomer gel base containing 10% oleic acid loaded with nanoparticles enhanced and prolonged the anti-inflammatory effects of this drug to more than 12 h in Aerosil-induced rat paw edema model.

Lipid nanocapsules: a new platform for nanomedicine

Nanomedicine, an emerging new field created by the fusion of nanotechnology and medicine, is one of the most promising pathways for the development of effective targeted therapies with oncology being the earlier and the most notable beneficiary to date. Indeed, drug-loaded nanoparticles provide an ideal solution to overcome the low selectivity of the anticancer drugs towards the cancer cells in regards to normal cells and the induced severe side-effects, thanks to their passive and/or active targeting to cancer tissues. Liposome-based systems encapsulating drugs are already used in some cancer therapies (e.g. Myocet, Daunoxome, Doxil). But liposomes have some important drawbacks: they have a low capacity to encapsulate lipophilic drugs (even though it exists), they are manufactured through processes involving organic solvents, and they are leaky, unstable in biological fluids and more generally in aqueous solutions for being commercialized as such. We have developed new nano-cargos, the lipid nanocapsules, with sizes below the endothelium fenestration (phi<100 nm), that solve these disadvantages. They are prepared according to a solvent-free process and they are stable for at least one year in suspension ready for injection, which should reduce considerably the cost and convenience for treatment. Moreover, these new nano-cargos have the ability to encapsulate efficiently lipophilic drugs, offering a pharmaceutical solution for their intravenous administration. The lipid nanocapsules (LNCs) have been prepared according to an original method based on a phase-inversion temperature process recently developed and patented. Their structure is a hybrid between polymeric nanocapsules and liposomes because of their oily core which is surrounded by a tensioactive rigid membrane. They have a lipoprotein-like structure. Their size can be adjusted below 100 nm with a narrow distribution. Importantly, these properties confer great stability to the structure (physical stability>18 months). Blank or drug-loaded LNCs can be prepared, with or without PEG (polyethyleneglycol)ylation that is a key parameter that affects the vascular residence time of the nano-cargos. Other hydrophilic tails can also be grafted. Different anticancer drugs (paclitaxel, docetaxel, etoposide, hydroxytamoxifen, doxorubicin, etc.) have been encapsulated. They all are released according to a sustained pattern. Preclinical studies on cell cultures and animal models of tumors have been performed, showing promising results.