Kamla Pathak

Intranasal nanoemulsion based brain targeting drug delivery system of risperidone

The objective of investigation was to prepare nanoemulsion containing risperidone (RSP) to accomplish the delivery of drug to the brain via nose. Risperidone nanoemulsion (RNE) and mucoadhesive nanoemulsion (RMNE) were characterized for drug content, pH, percentage transmittance, globule size and zeta potential. Biodistribution of RNE, RMNE, and risperidone solution (RS) in the brain and blood of Swiss albino rats following intranasal (i.n.) and intravenous (i.v.) administration was examined using optimized technetium labeled ((99m)Tc-labeled) RSP formulations. Gamma scintigraphy imaging of rat brain following i.v. and i.n. administrations were performed to ascertain the localization of drug in brain. The brain/blood uptake ratio of 0.617, 0.754, 0.948, and 0.054 for RS (i.n.), RNE (i.n.), RMNE (i.n.), and RNE (i.v.), respectively, at 0.5h are indicative of direct nose to brain transport bypassing the blood-brain barrier. Higher drug transport efficiency (DTE%) and direct nose to brain drug transport (direct transport percentage, DTP%) for mucoadhesive nanoemulsions indicated more effective and best brain targeting of RSP amongst the prepared nanoemulsions. Studies conclusively demonstrated rapid and larger extent of transport of RSP by RMNE (i.n.) when compared to RS (i.n.), RNE (i.n.) and RNE (i.v.) into the rat brain.

Nanostructured lipid carrier versus solid lipid nanoparticles of simvastatin: Comparative analysis of characteristics, pharmacokinetics and tissue uptake

Nanostructured lipid carrier (NLC) system of simvastatin was investigated for improvement in release, pharmacokinetics and biodistribution over its solid lipid nanoparticles (SLN). The NLC formulations prepared by solvent injection technique were optimized by 2(3) full factorial design. Optimized NLC was deduced on the basis of dependent variables that were analyzed using Design expert 8.0.2 software (Stat Ease, Inc., USA). Pareto charts and response surface plots were utilized to study the effect of variables on the response parameters. The optimized NLC was a suspension of nanosized homogeneous particles with significantly higher entrapment efficiency (>90%) and lower recrystallization properties (p<0.01) than SLNs. The pharmacokinetic parameters of Tc(99) labeled optimized NLC in mice, obtained using Quickcal software (Plexus, India) revealed 4.8 folds increase in bioavailability as compared to simvastatin suspension and 2.29 folds as compared to SLNs. Biodistribution study revealed preferential accumulation of NLC in the liver and this is advantageous because liver is the target organ for simvastatin. IVIVC studies demonstrated level A correlation between in vitro release and percent drug absorbed. This investigation demonstrated the superiority of NLC over SLN for improved oral delivery and it was deduced that the liquid lipid, oleic acid was the principal formulation factor responsible for the improvement in characteristics, pharmacokinetics and biodistribution of NLCs.

Nanosized ethanolic vesicles loaded with econazole nitrate for the treatment of deep fungal infections through topical gel formulation

UNLABELLED This project aimed at developing nanovesicles of econazole nitrate (EN) and formulating them as a suitable dermatological gel for improved therapeutic efficacy, better dispersity, and good storage stability. Ethosomes were prepared by cold method and evaluated for the mean diameter, surface charge, and entrapment efficiency. Optimized ethosomes with vesicle size and entrapment efficiency of 202.85 ± 5.10 nm and 81.05 ± 0.13%, respectively, were formulated as Carbopol 934 NF gels with varied permeation enhancers (G1-G7), and compared with liposomal and hydroethanolic gels. The pharmacotechnical evaluation of gels demonstrated G6 with a flux rate of 0.46 ± 0.22 μg/cm(2) hr(1/2) as the best formulation that was able to exhibit controlled release of EN for 12 hours across rat skin, and percent drug diffused from ethosomes was nearly twofold higher than liposomal and hydroethanolic gels. Confocal laser scanning microscopy demonstrated drug permeation as far as the last layer of epidermis (stratum basale). Stability profile of the prepared system assessed for 180 days revealed very low aggregation and insignificant growth in vesicular size. The results collectively suggest that because of the controlled drug release, better antifungal activity, and good storage stability, EN ethosomal gel has tremendous potential to serve as a topical delivery system. FROM THE CLINICAL EDITOR Ethosomal gel of econazole nitrate was found to have outstanding potential to serve as a topical delivery system, enabling controlled drug release, providing better antifungal activity, and good storage stability.

Mucoadhesive nanoemulsion-based intranasal drug delivery system of olanzapine for brain targeting

The objective of the present study was to optimize olanzapine nanoemulsion (ONE), for nose-to-brain delivery. The nanoemulsions and olanzapine mucoadhesive nanoemulsions (OMNEs) were prepared using water titration method and characterized for technical and electrokinetic properties. Biodistribution of nanoemulsions and olanzapine solution (OS) in the brain and blood of rats following intranasal (intranasal) and intravenous (intravenous) administrations were examined using optimized technetium-labeled (99mTc-labeled) olanzapine formulations. The brain/blood uptake ratios of 0.45, 0.88, 0.80, and 0.04 of OS (intranasal), ONE (intranasal), OMNE (intranasal), ONE (intravenous), respectively, at 0.5 h are indicative of direct nose-to-brain transport (DTP). Higher % drug targeting efficiency (%DTE) and %DTP for mucoadhesive nanoemulsions indicated effective brain targeting of olanzapine among the prepared nanoemulsions. Gamma scintigraphy imaging of the rat brain conclusively demonstrated rapid and larger extent of transport of olanzapine by OMNE (intranasal), when compared with OS (intranasal), ONE (intranasal), and ONE (intravenous), into the rat brain.

Porous carriers for controlled/modulated drug delivery.

Considerable research efforts have been directed in recent years towards the development of porous carriers as controlled drug delivery matrices because of possessing several features such as stable uniform porous structure, high surface area, tunable pore size and well-defined surface properties. Owing to wide range of useful properties porous carriers have been used in pharmaceuticals for many purposes including development of floating drug delivery systems, sustained drug delivery systems. Various types of pores like open, closed, transport and blind pores in the porous solid allow them to adsorb drugs and release them in a more reproducible and predictable manner. Pharmaceutically exploited porous adsorbents includes, silica (mesoporous), ethylene vinyl acetate (macroporous), polypropylene foam powder (microporous), titanium dioxide (nanoporous). When porous polymeric drug delivery system is placed in contact with appropriate dissolution medium, release of drug to medium must be preceded by the drug dissolution in the water filled pores or from surface and by diffusion through the water filled channels. The porous carriers are used to improve the oral bioavailability of poorly water soluble drugs, to increase the dissolution of relatively insoluble powders and conversion of crystalline state to amorphous state.

Osmotic flow through asymmetric membrane: A means for controlled delivery of drugs with varying solubility

A nondisintegrating, controlled release, asymmetric membrane capsular system of flurbiprofen was developed and evaluated for controlled release of the drug to overcome some of its side effects. Asymmetric membrane capsules were prepared using fabricated glass mold pins by phase inversion process. The effect of different formulation variables was studied based on 23 factorial design; namely, level of osmogen, membrane thickness, and level of pore former. Effects of polymer diffusibility and varying osmotic pressure on drug release were also studied. Membrane characterization by scanning electron microscopy showed an outer dense region with less pores and an inner porous region for the prepared asymmetric membrane. Differential scanning calorimetry studies showed no incompatibility between the drug and the excipients used in the study. In vitro release studies for all the prepared formulations were done (n=6). Statistical test (Dunnett multiple comparison test) was applied for in vitro drug release atP>.05. The best formulation closely corresponded to the extra design checkpoint formulation by a similarity (f2) value of 92.94. The drug release was independent of pH but dependent on the osmotic pressure of the dissolution medium. The release kinetics followed the Higuchi model and the mechanism of release was Fickian diffusion.

Formulation and Characterization of Nanoemulsion-Based Drug Delivery System of Risperidone

Risperidone nanoemulsion (NE) and mucoadhesive NE formulations were successfully prepared by the spontaneous emulsification method (titration method) using Capmul MCM as the oily phase on the basis of solubility studies. The NE formulation containing 8% oil, 44% Smix, 48% (wt/wt) aqueous phase that displayed an optical transparency of 99.82%, globule size of 15.5 ± 2.12 nm, and polydispersity of 0.172 ± 0.02 was selected for the incorporation of mucoadhesive components. The mucoadhesive formulation that contained 0.5% by weight of chitosan displayed highest diffusion coefficient that followed Higuchi model was free from nasal ciliotoxicity and stable for 3 months.

Physicochemical and physiological considerations for efficient nose-to-brain targeting

Introduction: Nasal drug delivery that exploits the olfactory and trigeminal neuronal pathways to deliver drugs to the brain is being widely explored by pharmaceutical companies, for the delivery of challenging drugs. Low-molecular-weight and lipophilic drugs are effectively absorbed by the intranasal route for efficacious brain targeting; however, high-molecular-weight and hydrophilic drugs present challenges in intranasal delivery. Areas covered: The present review critically evaluates the physicochemical properties of drugs and formulation variables that influence brain targeting by the intranasal route. It also encompasses the influence of physiological factors of the nose that can influence absorption and the strategies utilized to increase nasal drug absorption. Expert opinion: The challenges of drug delivery to the brain can be overcome by chemical and pharmaceutical approaches; current research is focused on developing novel drug delivery systems for both local and systemic actions. Nose-to-brain targeting has vast potential for commercialization, as these systems allow the lowering of doses, by direct targeting of the active molecule that provides easy attainment of the effective concentration at the target site. Consequently, these systems are being explored for the delivery of biologically active molecules, to treat the ailments of the CNS and various proteins, amino acids and hormones.

A review on mucoadhesive polymer used in nasal drug delivery system.

This update review is on mucoadhesive polymers used in nasal dosage forms. The nasal mucosa provides a potentially good route for systemic drug delivery. One of the most important features of the nasal route is that it avoids first-pass hepatic metabolism, thereby reducing metabolism. The application of mucoadhesive polymers in nasal drug delivery systems has gained to promote dosage form residence time in the nasal cavity as well as improving intimacy of contact with absorptive membranes of the biological system. The various new technology uses in development of nasal drug delivery dosage forms are discussed. The various dosage forms are vesicular carriers (liposome, noisome), nanostructured particles, prodrugs, in situ gelling system with special attention to in vivo studies.

Statins therapy: a review on conventional and novel formulation approaches.

Background and objective  High levels of cholesterol lead to atherosclerosis, a factor predisposing to the development of coronary artery disease. Statin drugs, i.e. HMG‐CoA reductase inhibitors, have been known since the end of the last century for their benefits against cardio‐ and cerebrovascular diseases and are widely used clinically. This review aims at compiling the research inputs being made for developing therapeutically efficacious dosage forms that have the potential to surmount the limitations of conventional dosage forms of statins.