Sulfobutylether-ß-cyclodextrin: A functional biopolymer for drug delivery applications.

Sulfobutylether ß-cyclodextrin (SBE-ß-CD) is a polyanionic cyclic oligosaccharide that contains glucopyranose units forming a torus ring-like structure. SBE-ß-CD is gifted with many favorable properties viz. relatively high solubility (>50 folds compared to ß-CD), improved stability, and biocompatibility that praised SBE-ß-CD as a smart polymer for drug delivery applications. Commercially, SBE-ß-CD is popular by its brand name Captisol®. The present review discusses the structure, properties, and preparation methods of SBE-ß-CD-based inclusion complexes (ICs). Furthermore, we discuss here the preparation and applications of SBE-ß-CD ICs-based nanoparticulate drug delivery systems, which combines the merits of both, ICs (enhanced solubility) and nanoparticles (NPs, targeted therapy). Patents on and FDA-approved Captisol®-enabled products are tabulated in the benefit of readers. The toxicological aspects and current clinical status of SBE-ß-CD or SBE-ß-CD-based products are briefly explained in the present review. In our opinion, the present review would be a pathfinder to allow dissemination of information on SBE-ß-CD.

Mannose-anchored N,N,N-trimethyl chitosan nanoparticles for pulmonary administration of etofylline.

Drug delivery to lungs via pulmonary administration offers potential for the development of new drug delivery systems. Here we fabricated the etofylline (ETO) encapsulated mannose-anchored N,N,N-trimethyl chitosan nanoparticles (Mn-TMC NPs). The prominent characteristics like biocompatibility, controlled release, targeted delivery, high penetrability, enhanced physical stability, and scalability mark Mn-TMC NPs as a viable alternative to various nanoplatform technologies for effective drug delivery. Mannosylation of TMC NPs leads to the evolution of new drug delivery vehicle with gratifying characteristics, and potential benefits in efficient drug therapy. It is widely accepted that following pulmonary administration, the introduction of mannose to the surface of drug nanocarriers provide selective macrophage targeting via receptor-mediated endocytosis. The fabricated Mn-TMC NPs exhibited particle size of 223.3 nm, PDI 0.490, and ζ-potential -19.1 mV, drug-loading capacity 76.26 ± 1.2%, and encapsulation efficiency of 91.75 ± 0.88%. Sustained drug release, biodegradation studies, stability, safety, and aerodynamic behavior revealed the effectiveness of prepared nanoformulation for pulmonary administration. In addition, the in vivo pharmacokinetic studies in Wistar rat model revealed a significant improvement in therapeutic efficacy of ETO, illustrating mannosylation a promising approach for efficient therapy of airway diseases following pulmonary administration.

N,N,N­trimethyl chitosan modified flaxseed oil based mucoadhesive neuronanoemulsions for direct nose to brain drug delivery.

Here we fabricated flaxseed oil-based neuronanoemulsions (NNEs) which were further surface-modified with a mucoadhesive polymer, N,N,N­trimethyl chitosan (TMC) to form mucoadhesive neuronanoemulsions (mNNEs). The NNEs were loaded with high partitioning ropinirole-dextran sulfate (ROPI-DS) nanoplex and fabricated using hot high-pressure homogenization (HPH) technique. NNEs were optimized using Central Composite experimental design. TMC modified mNNE have not been prepared yet for direct nose to brain drug delivery. Here, an objective to provide controlled drug release with prolonged residence on the nasal mucosa for the treatment of Parkinson's disease (PD) is at prime consideration. Enhanced brain targeting through BBB bypass drug delivery, improved therapeutic efficacy through enhanced retention of mNNE formulation over nasal mucosal membrane, reduced dose and frequency of administration, and safety were further expected outcomes of this experiment. The mNNE formulation was subjected to 6 month stability assessment. The mNNE formulation was administered to the Swiss albino mice model via intranasal route and both, the plasma and brain pharmacokinetics were estimated. The in vivo studies performed on mice exhibited high brain targeting efficiency of mNNE formulation through nose to brain delivery via olfactory pathway. The prepared intranasal mNNEs could be on the clinics, if investigated more for behavioral and neurotoxicity studies.

Xyloglucan: A functional biomacromolecule for drug delivery applications.

The near future of drug delivery system would lie in the search of a versatile and innocuous material, based mostly on the natural resources. The tamarind seed xyloglucan (XG) is a natural neutral hemicellulose and a hydrophilic polysaccharide consisting of a main chain of glucan backbone with xylose and galactose side chains. XG is endowed with idiosyncratic mucoadhesive and in situ gelling properties which rated XG as an attractive, functional polymer for numerous drug delivery applications. In milieu of this, the present review is designed to underline the plausible potential of XG or XG-based systems in drug delivery. The feasibility of surface-tailoring, the flexibility of chemical-modification, and the possibility as ligand-conjugations grant XG an extraordinary consideration in the scientific territory. The authors are hopeful that the versatility of XG would meet the expectations of regulatory authorities and the XG-based products will serve the therapeutic needs of the community in the future, if sufficiently investigated and promising outcomes are obtained in human subjects.

N,N,N-Trimethyl chitosan: An advanced polymer with myriad of opportunities in nanomedicine.

N,N,N-trimethyl chitosan (TMC), a quaternized hydrophilic derivative of chitosan (CHT), outperformed the well-known solubility issues raised by CHT. The excellent properties offered by TMC provide it a significant edge for nanoparticle (NP) formation over other nanocarrier materials. Recently, TMC NPs have been applied to various fields like pharmaceutical, biomedical, biomaterials, and biotechnological field. The aim of this review is, therefore, to bring the TMC into the limelight so as to appraise it as an attractive functional polymer for nanomedicine applications which is facing oversight, at present, by regulatory agencies and manufacturers. The versatility of surface-tailoring, the capability of further chemical modifications, and the feasibility of ligand-conjugations in TMC polymer will further assist the scientists for reaching new dimensions in the nano-assembly of novel structures based on TMC.

New nasal nanocomplex self-assembled from charged biomacromolecules: N,N,N-Trimethyl chitosan and dextran sulfate.

Although chitosan (CHT, a linear cationic polysaccharide) is biodegradable, biocompatible, non-toxic, and mucoadhesive in nature, the low solubility of CHT in aqueous and alkaline media limits its applicability in pharmaceutical and biomedical field. This necessitate the introduction of new chemically-modified derivatives of CHT those can surmount the solubility barrier. Herein, N,N,N-trimethyl chitosan (TMC), a quaternized hydrophilic derivative of CHT, was synthesized by two-step reductive methylation of CHT and characterized for (1)H NMR and zeta potential measurements. Polyelectrolyte complexes (PECs) based on TMC and dextran sulfate (DS) were prepared via ionic interactions between charged functional groups of former polysaccharides at different pH conditions (pH 5, 8, 10, and 12) and characterized for physicochemical (particle size and zeta potential) and solid- state characterizations (HR-TEM, SEM, FTIR, TGA and XRD). At alkaline pH conditions, the participant polymer chains (TMC and DS) are sufficiently close to form more stable PECs. The release efficiency was assessed after loading a model drug into optimized PEC formulation. Data indicated that the PECs fabricated at alkaline pH presents a reliable formulation for pharmaceutical and biomedical applications.

Polyelectrolyte complexes: mechanisms, critical experimental aspects, and applications.

The polyelectrolyte complexes (PECs) are versatile formulations formed by electrostatic interactions between oppositely charged biopolymers. PECs have been investigated widely by the researchers to explore the virtues of this formulation viz. high biocompatibility, excellent biodegradability, low toxicity, cost-effective, environment-friendly, and energy-efficient production. The prime object of the present review is to present the prominent features of PECs including mechanism of PEC formation, structural models of PECs, interactions involved in PEC formation, steps involved in PEC fabrication, factors affecting the formation of PECs and applications of PECs. The patents pertaining to PECs have briefly been tabulated as well.

Controlled synthesis of N,N,N-trimethyl chitosan for modulated bioadhesion and nasal membrane permeability.

In an experiment to explore the bioadhesion, biocompatibility, and membrane permeation properties, the controlled synthesis of N,N,N-trimethyl chitosan (TMC) was carried out by two-step reductive methylation of chitosan (CHT). Methylation was confirmed by (1)H NMR (δ=3.1 ppm) and FTIR analysis (CH stretch at 1,485 cm(-1)). The TMC was further characterized by DSC, TGA, XRD, HR-TEM, SEM, and elemental analysis. Findings revealed improved solubility, enhanced viscosity, increased swelling index and higher molecular weight of TMC over CHT. Comparative evaluation validated increased bioadhesion potential, and improved ex vivo biocompatibility of TMC compared to CHT. Increased bioadhesion of TMC NPs over CHT NPs can be attributed to the strong electrostatic interactions between cationic amino groups with anionic sialic and sulfonic acid moieties contained in the mucin of the nasal mucus. Ex vivo biocompatibility studies suggested that the NP formulations of both biopolymers were biocompatible and could be applied safely on the nasal epithelium. Ex vivo permeation studies executed on excised cattle nasal mucosa illustrated improved permeability of TMC NPs over CHT NPs. In the author's opinion, two-step reductive methylation of CHT could be an attractive strategy to improve its solubility, bioadhesion, and permeation characteristics without affecting biocompatibility across the mucosal surfaces.

Brain-blood ratio: implications in brain drug delivery.

INTRODUCTION: The brain-blood ratio is an important model correlating the brain-targeting ability of neurotherapeutics with the CNS pharmacokinetics, which need to be presented before the scientific community for exploration of its scientific worth. The purpose of this article is to bring this key concept and its precise discussion to the attention of the researchers. AREAS COVERED: Three major points are discussed herein: First, the significance of brain-blood ratio with respect to investigational neurotherapeutics, and carrier systems and correlation of its research findings with the brain targeting efficiency. Second, the various factors influencing the brain-blood ratio. Third, the various strategies for enhancing the brain-blood ratio. In addition, the benchmark criteria for CNS-likeness of drug molecules and the correlation of brain-blood ratio with brain targeting ability of neurotherapeutics have been tabulated. EXPERT OPINION: The brain-blood ratio (also referred to as the brain-plasma ratio) represents one of the tools available today for estimation of CNS pharmacokinetics. It is preferred over other complicated techniques (in situ brain perfusion and microdialysis) due to its ease of use and practicality. We are optimistic that the brain-blood ratio offers an excellent way of evaluating brain-targeting efficiency of neurotherapeutics effectively. In our opinion, it is a very fundamental aspect of brain bioavailability and needs to be presented in a precise way.

Nanotechnology-mediated nose to brain drug delivery for Parkinson's disease: a mini review.

Nose to brain delivery of neurotherapeutics have been tried by several researchers to explore the virtues of this route viz. circumvention of BBB, avoidance of hepatic metabolism, practicality, safety, ease of administration and non-invasiveness. Nanoparticle (NP) therapeutics is an emerging modality for the treatment of Parkinson's disease (PD) as it offers targeted delivery and enhances the therapeutic efficacy and/or bioavailability of neurotherapeutics. This review presents a concise incursion into the nanomedicines suitable for PD therapy delivered via naso-brain transport. Clinical signs of PD, its pathophysiology, specific genetic determinants, diagnosis and therapy involved have been hashed out. Properties of brain-targeting NPs, transport efficacy and various nanocarriers developed so far also been furnished. In our opinion, nanotechnology-enabled naso-brain drug delivery is an excellent means of delivering neurotherapeutics and is a promising avenue for researchers to develop new formulations for the effective management of PD.

Insights into drug delivery across the nail plate barrier.

Topical therapy is at the forefront in treating nail ailments (especially onychomycosis and nail psoriasis) due to its local effects, which circumvents systemic adverse events, improves patient compliance and reduces treatment cost. However, the success of topical therapy has been hindered due to poor penetration of topical therapeutics across densely keratinized nail plate barrier. For effective topical therapy across nail plate, ungual drug permeation must be enhanced. Present review is designed to provide an insight into prime aspects of transungual drug delivery viz. nail structure and physiology, various onychopathies, techniques of nail permeation enhancement and in vitro models for trans-nail drug permeation studies. Updated list of drug molecules studied across the nail plate and key commercial products have been furnished with sufficient depth. Patents pertinent to, and current clinical status of transungual drug delivery have also been comprehensively reviewed. This is the first systematic critique encompassing the detailed aspects of transungual drug delivery. In our opinion, transungual drug delivery is a promising avenue for researchers to develop novel formulations, augmenting pharmaceutical industries to commercialize the products for nail disorders.

Novel surface modified polymer-lipid hybrid nanoparticles as intranasal carriers for ropinirole hydrochloride: in vitro, ex vivo and in vivo pharmacodynamic evaluation.

Here we report fabrication and evaluation of novel surface modified polymer-lipid hybrid nanoparticles (PLN) as robust carriers for intranasal delivery of ropinirole hydrochloride (ROPI HCl). Sustained release, avoidance of hepatic first pass metabolism, and improved therapeutic efficacy are the major objectives of this experiment. PLN were fabricated by emulsification-solvent diffusion technique and evaluated for physicochemical parameters, in vitro mucoadhesion, in vitro diffusion, ex vivo permeation, mucosal toxicity and stability studies. Box-Behnken experimental design approach has been employed to assess the influence of two independent variables, viz. surfactant (Pluronic F-68) and charge modifier (stearylamine) concentration on particle size, ζ-potential and entrapment efficiency of prepared PLN. Numerical optimization techniques were used for selecting optimized formulation sample, further confirmed by three dimensional response surface plots and regression equations. Results of ANOVA demonstrated the significance of suggested models. DSC and SEM analysis revealed the encapsulation of amorphous form of drug into PLN system, and spherical shape. PLN formulation had shown good retention with no severe signs of damage on integrity of nasal mucosa. Release pattern of drug-loaded sample was best fitted to zero order kinetic model with non-Fickian super case II diffusion mechanism. In vivo pharmacodynamic studies were executed to compare therapeutic efficacy of prepared nasal PLN formulation against marketed oral formulation of same drug. In summary, the PLN could be potentially used as safe and stable carrier for intranasal delivery of ROPI HCl, especially in treatment of Parkinson's disease.

Novel surface modified solid lipid nanoparticles as intranasal carriers for ropinirole hydrochloride: application of factorial design approach.

Present investigation deals with intranasal delivery of ropinirole hydrochloride (ROPI HCl), loaded in solid lipid nanoparticles (SLNs). Prime objectives of this experiment are avoidance of hepatic first pass metabolism and to improve therapeutic efficacy in the treatment of Parkinson's disease. SLNs were fabricated by emulsification-solvent diffusion technique. A 3(2)-factorial design approach has been employed to assess the influence of two independent variables, namely Pluronic F-68 and stearylamine concentration on particle size, ζ-potential and entrapment efficiency of prepared SLNs. Prepared samples were further evaluated for in vitro drug diffusion, ex vivo drug permeation, histopathological and stability studies. Differential scanning calorimetry analysis revealed the encapsulation of amorphous form of drug into lipid matrix, while scanning electron microscopy studies indicated the spherical shape. Fabricated SLNs had shown no severe signs of damage on integrity of nasal mucosa. Release pattern of prepared drug-loaded sample was best fitted to zero-order kinetic model with non-Fickian super case II diffusion mechanism. In vivo pharmacodynamic studies were carried out to compare therapeutic efficacy of prepared nasal formulation against marketed oral formulation. Results of analysis of variance demonstrated the significance of suggested model. Three-dimensional response surface plots and regression equations confirmed the corresponding influence of selected independent variables on measured responses. Our findings suggested the feasibility of investigated system for intranasal administration.