Formulation and Characterization of Phytostanol Ester Solid Lipid Nanoparticles for the Management of Hypercholesterolemia: An ex vivo Study.

BACKGROUND: Phytostanols are naturally occurring compounds that reduce blood cholesterol levels significantly. However, their aqueous insolubility poses formulation challenges. AIM: To formulate and characterize solid lipid nanoparticle carriers for phytostanol esters to enhance the bioavailability of phytostanols. METHODS: Phytostanol ester solid lipid nanoparticles were formulated by the microemulsion method. They were characterized for particle size distribution, polydispersity index, shape, surface charge, entrapment efficiency, stability, chemical structure, and thermal properties. The uptake of the formulation by cell lines, HepG2 and HT-29, and its effect on cell viability were evaluated. RESULTS: The formulation of solid lipid nanoparticles was successfully optimised by varying the type of lipids and their concentration relative to that of surfactants in the present study. The optimised formulation had an average diameter of (171 ± 9) nm, a negative surface charge of (-23.0 ± 0.8) mV and was generally spherical in shape. We report high levels of drug entrapment at (89 ± 5)% in amorphous form, drug loading of (9.1 ± 0.5)%, nanoparticle yield of (67 ± 4)% and drug excipient compatibility. The biological safety and uptake of the formulations were demonstrated on hepatic and intestinal cell lines. CONCLUSION: Phytostanol ester solid lipid nanoparticles were successfully formulated and characterized. The formulation has the potential to provide an innovative drug delivery system for phytostanols which reduce cholesterol and have a potentially ideal safety profile. This can contribute to better management of one of the main risk factors of cardiovascular diseases.

Simple HPLC-UV method for the quantification of metformin in human plasma with one step protein precipitation.

This study presents the optimization of a simple HPLC-UV method for the determination of metformin in human plasma. Ion pair separation followed by UV detection was performed on deproteinized human plasma samples. The separation was carried out on a Discovery Reversed Phase C-18 column (250 × 4.6 mm, 5 µm) with UV detection at 233 nm. The mobile phase contained 34% acetonitrile and 66% aqueous phase. Aqueous phase contained 10 mM KH2PO4 and 10 mM sodium lauryl sulfate. Aqueous phase pH was adjusted to 5.2. The mobile phase was run isocratically. The flow rate of the mobile phase was maintained at 1.3 ml/min. The linearity of the calibration curve was obtained in the concentration range of 0.125-2.5 µg/ml and coefficient of determination (R (2)) was found to be 0.9951. The lowest limit of quantification and detection was 125 and 62 ng/ml respectively. No endogenous substances were found to interfere with the peaks of drug and internal standard. The intra-day and inter-day coefficient of variations was 6.97% or less for all the selected concentrations. The relative errors at all the studied concentrations were 5.60% or less. This method is time efficient and samples are easy to prepare with minimum dilution. So, it can be applied for monitoring metformin in human plasma.

Effect of knowledge and perception on adherence to iron and folate supplementation during pregnancy in Kathmandu, Nepal.

BACKGROUND: Adherence to iron and folate supplementation during pregnancy is considered key to prevention and control of iron deficiency anemia. Nepal-like other developing countries-faces problems with adherence vis-a-vis iron/folate supplementation. OBJECTIVE: This descriptive survey aimed to assess the effect ofknowledge and perception ofpregnant women on adherence to iron/folate supplementation in Kathmandu, Nepal. MATERIAL AND METHOD: The present study was conducted in Paropakar Maternity and Womens' Hospital in Kathmandu. Systematic random sampling was used to select 406 persons who were either given a self-administered questionnaire or interviewed. RESULTS: 73.2% of the respondents showed good adherence. Bivariate analysis revealed significant associations between adherence and both knowledge and perception (p<0.05), but through multiple linear regression analysis only perception was found to be statistically associated with adherence (p<0.05). Further multivariate analysis demonstrated that the most important predictors of adherence were: perception of side effects, availability, forgetfulness and reminders from family. CONCLUSION: Adherence to iron/folate supplementation among women during pregnancy needs continuous improvement by minimizing the perception of constraints (viz., side-effects and forgetfulness) and, enhancing availability andfamily support.

In vivo evaluation of nicotine lyophilised nasal insert in sheep.

The nasal route offers an attractive means of delivering a drug directly to the systemic circulation and avoiding hepatic first-pass metabolism, although rapid mucociliary clearance can be detrimental to nasal absorption. The in vitro and in vivo characteristics of a nasal insert formulation prepared by lyophilisation of a viscous HPMC gel solution designed to overcome this problem were studied. In vitro release of nicotine from the lyophilised insert was compared with powder and spray formulations. Stability and characterisation studies were carried out using dynamic vapour sorption, scanning electron microscopy and HPLC analysis. Nicotine formulations were administered to eight wether sheep in a randomised four-way cross-over study, and plasma nicotine assessed comparing the nasal insert formulation with conventional nasal powder, nasal spray and IV doses. In vitro release studies demonstrated prolonged nicotine release from the nasal insert formulation compared to a powder and liquid. In vivo plasma profiles appeared to show prolonged plasma nicotine levels compared to the conventional formulations, although T(max), C(max) and AUC parameters for the insert were not significantly different due to high variability in the pharmacokinetic data. In conclusion, the nasal insert displayed a promising prolonged plasma profile, which must be investigated further to provide statistical significance to prove the effect.