Challenges and trends in apomorphine drug delivery systems for the treatment of Parkinson's disease

Parkinson's disease(PD) is a chronic debilitating disease affecting approximately 1% of the population over the age of 60. The severity of PD is correlated to the degree of dopaminergic neuronal loss. Apomorphine has a similar chemical structure as the neurotransmitter dopamine and has been used for the treatment of advanced PD patients. In PD patients,apomorphine is normally administered subcutaneously with frequent injections because of the compound's extensive hepatic first-pass metabolism. There is, hence, a large unmet need for alternative administrative routes for apomorphine to improve patient compliance.The present review focuses on the research and development of alternative delivery of apomorphine, aiming to highlight the potential of non-invasive apomorphine therapy in PD,such as sublingual delivery and transdermal delivery.

Spray drying of fenofibrate loaded nanostructured lipid carriers

The conversion of aqueous dispersion of nanostructured lipid carriers(NLCs) into dry powder by spray drying could be a useful approach to render NLCs with better physical chemical stability than the aqueous dispersion. In this study, aqueous NLC dispersion containing fenofibrate was converted into dry, easily reconstitutable powder using spray drying. A central composite face centered design(CCFD) was used to investigate the influence of the ratio of lipid to protectant(mannitol and trehalose) and crystallinity of spray-dried powder on the particle size, yield and residual moisture content of the dried powder. A linear relationship(R2= 0.9915) was established between the crystalline content of the spray-dried powders against the ratio of mannitol to trehalose from 3:7 to 10:0(w/w). Spray drying of NLC aqueous dispersion using a mannitol and trehalose mixture resulted in an increase in particle size of the NLCs after reconstitution in water as compared to that in the initial aqueous dispersion. The decrease in crystallinity of the dry powder by reducing the ratio of mannitol to trehalose could improve the reconstitution of the NLCs in water. However the yield and residual moisture content of dry powder decreased with an increase in the ratio of mannitol to trehalose. Lipid nanoparticles were able to retain the drug incorporation and the prolonged drug release profile after spray drying. The experimental model was robust, and suggested that spray drying is a viable technique for the conversion of NLCs into dry powder.

Recent advances in drug delivery applications of cubosomes,hexosomes,and solid lipid nanoparticles

The use of lipid nanocarriers for drug delivery applications is an active research area,and a great interest has particularly been shown in the past two decades.Among different lipid nanocarriers,ISAsomes(Internally self-assembled somes or particles),including cubosomes and hexosomes,and solid lipid nanoparticles(SLNs)have unique structural features,making them attractive as nanocarriers for drug delivery.In this contribution,we focus exclusively on recent advances in formation and characterization of ISAsomes,mainly cubosomes and hexosomes,and their use as versatile nanocarriers for different drug delivery applications.Additionally,the advantages of SLNs and their application in oral and pulmonary drug delivery are discussed with focus on the biological fates of these lipid nanocarriers in vivo.Despite the demonstrated advantages in in vitro and in vivo evaluations including preclinical studies,further investigations on improved understanding of the interactions of these nanoparticles with biological fuids and tissues of the target sites is necessary for effcient designing of drug nanocarriers and exploring potential clinical applications.

Exploring the utility of the Chasing Principle:influence of drug-free SNEDDS composition on solubilization of carvedilol, cinnarizine and R3040 in aqueous suspension

This study assessed the influence of the composition of drug-free SNEDDS co-dosed with aqueous suspensions of carvedilol(CAR), cinnarizine(CIN) or R3040 on drug solubilization in a twocompartment in vitro lipolysis model. Correlation of drug log P or solubility in SNEDDS with drug solubilization during in vitro lipolysis in the presence of drug-free SNEDDS was assessed. SNEDDS with varying ratios of soybean oil:Maisine 35-1(1:1, w/w) and Kolliphor RH40, with ethanol at 10%(w/w) were used. SNEDDS were named F65, F55 and F20(numbers refer to the percentage of lipids) and aqueous suspensions without drug-free SNEDDS(F0) were also analyzed. While the ranking order of drug solubilization was F65? F55? F204F0 for CAR; F65? F554F204F0 for CIN and F65? F55? F204F0 for R3040-with higher CAR solubilization than for R3040 and CIN-the ranking of S_(eq)of CAR, CIN and R3040 in SNEDDS was F65 o F55o F20, F65? F554F20 and F654F554F20, respectively. Therefore, the composition of SNEDDS influenced the solubilization of CIN, but not CAR and R3040. Furthermore, high S_(eq) in SNEDDS did not reflect high drug solubilization. As CAR(log P 3.8) showed higher solubilization than CIN(log P 5.8) and R3040(log P 10.4), a correlation between drug log P and drug solubilization was observed.