Development and optimization of nanoemulsion based gel for enhanced transdermal delivery of nitrendipine using box-behnken statistical design.

Objective: The purpose of present research was to develop and statistically optimize nitrendipine nanoemulsion gel for transdermal delivery using box-behnken statistical design.Method: The nanoemulsion formulations bearing nitrendipine were prepared by application of ternary phase diagram and spontaneous emulsification method. Box-behnken design was employed for the optimization of nitrendipine loaded nanoemulsion. The independent variables were oil, surfactant and co-surfactant while globule size, drug content and zeta potential were dependent variables. The optimized nanoemulsion formulation was incorporated into gel and evaluated for in-vitro release, ex-vivo permeation studies, confocal laser scanning microscopy, skin irritation and histopathological studies.Results: The optimized formulation through box-behnken statistical design showed globule size of 20.43 ± 1.50 nm, drug content of 97.05 ± 1.77% and zeta potential of -15.45 ± 0.35 mV. The ex-vivo study confirmed the enhanced delivery of nitrendipine from nanoemulsion gel than compare to drug solution by virtue of better permeation and solubility. Nanoemulsion gel was proved significantly superior by confocal laser scanning microscopy for satisfactory permeation and distribution of gel, deep into the rat skin. The optimized gel was found with no allergic dermal effects and was proved safe by histopathological studies for transdermal application.Conclusions: Results reveals that developed nitrendipine nanoemulsion gel overcomes the limitation of low penetration and accentuate permeation through albino Wistar rat skin. It was concluded that nanoemulsion gel could be utilized as a potential carrier for transdermal delivery of nitrendipine.

Formulation, in vitro, and in vivo evaluation of matrix-type transdermal patches containing olanzapine.

Transdermal patches of olanzapine were aimed to be prepared to overcome the side effects by oral application. The strategy was formulation of eudragit-based polymeric films to prepare transdermal patches by using nonionic (span-20), anionic (sodium lauryl sulfate), cationic surfactant (benzalkonium chloride), and vegetable oil (olive oil) as permeation enhancers. The patches were subjected to physicochemical, in vitro release and ex vivo permeation studies. On the basis of in vitro release performance, ERL 100:ERS 100 in the ratio of 3:2 was selected for incorporation of permeation enhancers. The permeation studies showed that formulation containing 10% span 20 (OD3) exhibited greatest cumulative amount of drug permeated (19.02 ± 0.21 mg) in 72 h, so OD3 was concluded as optimized formulation and assessed for pharmacokinetic, pharmacodynamic, and skin irritation potential. In vivo studies of optimized olanzapine patch in rabbit model revealed prolongation of action with Frel 116.09% during 72-h study period. Neuroleptic efficacy of transdermal patch was comparable to oral formulation during rotarod and grip test in Wistar albino rats with no skin irritation. Thus, developed formulation of olanzapine is expected to improve the patient compliance, form better dosage regimen, and provide maintenance therapy to psychotic patients.

Quetiapine Fumarate Loaded Nanostructured Lipid Carrier for Enhancing Oral Bioavailability: Design, Development and Pharmacokinetic Assessment.

AIMS: The study aimed at developing and characterizing Nanostructured Lipid Carriers (NLC) of Quetiapine Fumarate (QF) by Design of Experiment (DoE) for the enhancement of bioavailability. BACKGROUND: QF, an anti-psychotic drug, has an oral bioavailability of 9% due to hepatic first- pass metabolism necessitating the use of high doses. Its side effects are dose -related and enhancement in bioavailability would result in minimization of side effects. OBJECTIVE: The objective of the study was the enhancement of bioavailability of the NLC of QF by preferential lymphatic uptake. METHODS: Hot emulsification-ultrasonication was the method of formulation using PrecirolATO5 and Oleic acid as solid and liquid lipids respectively. Poloxamer188 and Phospholipon90G were used as surfactant and stabilizer respectively. Solid:liquid lipid ratio and Phospholipon90G amount were independent variables and percent Entrapment Efficiency (%EE), Particle Size (PS) dependent variables during optimization by Central Composite Design. RESULTS: The optimized formulation showed a %EE of 77.21%, PS of 140.2 nm and surface charge of - 19.9mV. Higuchi kinetic model was followed during the in-vitro release. TEM revealed spherical, smooth nanoparticles. A pharmacokinetic study in rats showed AUC0-∞ of QF-NLC to be 3.93 times that of QF in suspension, suggesting significant enhancement in bioavailability. An increase in AUC0-∞ in cycloheximide untreated rats' group of QF-NLC by 2.43 times as compared to cycloheximide treated group, confirmed lymphatic absorption of QF- NLC. CONCLUSION: The results validated DoE as an appropriate tool for developing QF loaded NLC and proved NLC to be a promising delivery system for the enhancement of oral bioavailability of QF.

Herbicide Glyphosate: Toxicity and Microbial Degradation.

Glyphosate is a non-specific organophosphate pesticide, which finds widespread application in shielding crops against the weeds. Its high solubility in hydrophilic solvents, especially water and high mobility allows the rapid leaching of the glyphosate into the soil leading to contamination of groundwater and accumulation into the plant tissues, therefore intricating the elimination of the herbicides. Despite the widespread application, only a few percentages of the total applied glyphosate serve the actual purpose, dispensing the rest in the environment, thus resulting in reduced crop yields, low quality agricultural products, deteriorating soil fertility, contributing to water pollution, and consequently threatening human and animal life. This review gives an insight into the toxicological effects of the herbicide glyphosate and current approaches to track and identify trace amounts of this agrochemical along with its biodegradability and possible remediating strategies. Efforts have also been made to summarize the biodegradation mechanisms and catabolic enzymes involved in glyphosate metabolism.

Design and development of cefdinir niosomes for oral delivery.

OBJECTIVE: The aim of the present study was to develop nonionic surfactant based vesicles (niosomes) to improve poor and variable oral bioavailability of cefdinir. MATERIALS AND METHODS: Cefdinir niosomes were formulated by sonication method using varying concentration of surfactant (span 60), with and without soya lecithin, but the cholesterol ratio was kept constant in all the formulations. The influence of formulation variables such as surfactant concentration, soya lecithin presence or absence were optimized for size and entrapment efficiency. Drug excipient interaction studies were performed using FTIR, indicating compatibility of excipients with drug. RESULTS: The highest entrapment efficiency (74.56%) was observed when span 60, cefdinir, cholesterol and soya lecithin were used in the ratio of 5:1:1:1. The zeta sizer of the niosomal formulations showed the size range between 190 nm-1140 nm. The photomicrography showed round shape of vesicles and further nano size of niosomes was confirmed by scanning and transmission electron microscopy. The optimized niosomal formulations (F11 and F6) exhibited sustained in-vitro release of 94.91% and 94.07% respectively upto 12 h. The ex-vivo permeation studies of optimized formulation revealed that the niosomal dispersion improved cefdinir permeability across goat intestinal membrane as compared to plain drug solution and marketed suspension (Adcef®). Antimicrobial activity studies revealed that the niosomes potentiated bacteriostatic activity of cefdinir as compared to Adcef®. CONCLUSION: The niosomal formulation could be one of the promising delivery system for cefdinir with improved oral bioavailability and controlled drug release profile.

Natural oils as skin permeation enhancers for transdermal delivery of olanzapine: in vitro and in vivo evaluation.

The feasibility of development of transdermal delivery system of olanzapine utilizing natural oils as permeation enhancers was investigated. Penetration enhancing potential of corn (maize) oil, groundnut oil and jojoba oil on in vitro permeation of olanzapine across rat skin was studied. The magnitude of flux enhancement factor with corn oil, groundnut oil and jojoba oil was 7.06, 5.31 and 1.9 respectively at 5mg/ml concentration in solvent system. On the basis of in vitro permeation studies, eudragit based matrix type transdermal patches of olanzapine were fabricated using optimized concentrations of natural oils as permeation enhancers. All transdermal patches were found to be uniform with respect to physical characteristics. The interaction studies carried out by comparing the results of ultraviolet, HPLC and FTIR analyses for the pure drug, polymers and mixture of drug and polymers indicated no chemical interaction between the drug and excipients. Corn oil containing unsaturated fatty acids was found to be promising natural permeation enhancer for transdermal delivery of olanzapine with greatest cumulative amount of drug permeated (1010.68 µg/cm²/h) up to 24 h and caused no skin irritation. The fabricated transdermal patches were found to be stable. The pharmacokinetic characteristics of the final optimized matrix patch (T2) were determined after transdermal application to rabbits. The calculated relative bioavailability of TDDS was 113.6 % as compared to oral administration of olanzapine. The therapeutic effectiveness of optimized transdermal system was confirmed by tranquillizing activity in rotarod and grip mice model.