Sarwar Beg

Strategy for effective brain drug delivery

Blood-brain barrier (BBB) together with enzymes restricts the entry of substances for maintaining the internal milieu of the brain. Because of the presence of multiple endogenous transporters, BBB allows a selective entry of nutrients and minerals across it and limits the entry of foreign substances like drugs as well as neuropharmaceutical agents. This makes the CNS treatment ineffective. The conventional drug delivery systems which release drug into general circulation fail to deliver drugs effectively to brain and is therefore not very useful in treating certain diseases that affect CNS including Alzheimers disease, dementia, Parkinsons disease, mood disorder, AIDS, viral and bacterial meningitis. Therefore there is a need to develop and design approaches which specifically target to brain in a better and effective way. The present review enlightens about several novel approaches including nanotechnology based approach like nanoparticles, liposomes, antibody mediated delivery approach and application of genomics in brain drug targeting that would give an insight to the researchers, academia and industrialists.

Development of solid self-nanoemulsifying granules (SSNEGs) of ondansetron hydrochloride with enhanced bioavailability potential.

The current work aims to prepare the solid self-nanoemulsifying granules (SSNEGs) of ondansetron hydrochloride (ONH) to enhance its oral bioavailability by improving its aqueous solubility and facilitating its absorption though lymphatic pathways. Preformulation studies including screening of excipients for solubility and pseudoternary phase diagrams suggested the suitability of Capmul MCM as lipid, Labrasol as surfactant, and Tween 20 as cosurfactant for preparation of self-emulsifying formulations. Preliminary composition of the SNEDDS formulations were selected from the phase diagrams and subjected to thermodynamic stability studies and dispersibility tests. The prepared liquid SNEDDS formulations were characterized for viscosity, refractive index, droplet size and zeta potential. The TEM study confirmed the formation of nanoemulsion following dilution of liquid SNEDDS. The optimized liquid SNEDDS were transformed into free flowing granules by adsorption on the porous carriers like Sylysia (350, 550, and 730) and Neusilin™ US2. Solid state characterization employing the FTIR, DSC and powder XRD studies indicated lack of any significant interaction of drug with the lipidic and emulsifying excipients, and porous carriers. In vitro drug release studies indicated faster solubilization of the drug by optimized SSNEGs (over 80% within 30 min) vis-à-vis the pure drug (only 35% within 30 min). In vivo pharmacokinetic studies in Wistar rats observed significant increase in C(max) (3.01-fold) and AUC (5.34-fold) using SSNEGs compared to pure drug, whereas no significant difference (p>0.1) was observed with the liquid SNEDDS. Thus, the present studies ratify the bioavailability enhancement potential of SSNEGs of ONH prepared using porous carriers.

Systematic review of herbals as potential anti-inflammatory agents: Recent advances, current clinical status and future perspectives.

Many synthetic drugs reported to be used for the treatment of inflammatory disorders are of least interest now a days due to their potential side effects and serious adverse effects and as they are found to be highly unsafe for human assistance. Since the last few decades, herbal drugs have regained their popularity in treatment against several human ailments. Herbals containing anti-inflammatory activity (AIA) are topics of immense interest due to the absence of several problems in them, which are associated with synthetic preparations. The primary objective of this review is to provide a deep overview of the recently explored anti-inflammatory agents belonging to various classes of phytoconstituents like alkaloids, glycosides, terpenoids, steroids, polyphenolic compounds, and also the compounds isolated from plants of marine origin, algae and fungi. Also, it enlists a distended view on potential interactions between herbals and synthetic preparations, related adverse effects and clinical trials done on herbals for exploring their AIA. The basic aim of this review is to give updated knowledge regarding plants which will be valuable for the scientists working in the field of anti-inflammatory natural chemistry.

Dendrimers as Novel Systems for Delivery of Neuropharmaceuticals to the Brain

Most of the newly developed drugs fails to achieve sufficient bioavailability in to brain due to low water solubility and low permeability. Drug delivery systems are one method for achieving entry of molecules to their desired site of action within the body. Dendrimers are the customizable nanopolymers with uniform and well-defined particle size and shape. Dendrimers are of eminent interest for biomedical applications because of their ability to cross cell membranes. This potential pharmaceutical delivery system crosses the blood brain barrier (BBB) and other important target points. The high level of control over the dendritic architecture (size, branching density, surface functionality) make dendrimers ideal carriers in the field of brain drug delivery of anticancer, antiinflammatory, and antimicrobial agents. Examples of dendrimers such as poly(amidoamine) (PAMAM), poly(propylene imine) (PPI) and polyether-copolyester (PEPE), Glyco, PEGylated, peptide and pH dendrimers are of outmost significance. These dendrimers carry the drug molecules by physical interactions (encapsulation) or through chemical bonding (prodrug approach), while pH sensitive dendrimers are able to deliver drug molecules by alteration of ionic exchange in the brain microenvironment at the tumor site. Techniques employing dendrimers could be especially useful for drugs targeting to Alzheimers and Prions diseases. The present review should be of value to scientists who wish to work on the dendrimers for the delivery of molecules into the brain by systemic dosing.

Bioavailability Enhancement Strategies: Basics, Formulation Approaches and Regulatory Considerations

Poor solubility remains a major challenge for pharmaceutical industry, which is now considered to be an area of prime importance in the field of biomedical research. Approximately 40% new molecular entities (NMEs) synthesized in pharmaceutical R with advanced combinatorial chemistry and computer aided drug designing (CADD) approaches suffer from poor solubility and bioavailability related issues. Apart from these presence of intestinal tight junctional epithelial cells, transporters and enzymatic barriers further reduces the oral absorption of drugs. Implication of the novel lipid based nanocarriers and nanomaterials like dendrimers and carbon nanotubes as a delivery system can effectively enhance the oral bioavailability of drugs by breaching the barriers, and resolve all critics related to solubility and bioavailability. Thus prime objectives of this review are to give in-depth knowledge and critical appraisal on the barriers for poor oral bioavailability of drugs, along with various novel formulation approaches used for bioavailability enhancement such as lipid based formulations, nanosizing techniques, complexation with polymers and nanomaterials like dendrimers, carbon nanotubes, and penetration enhancers. Also it gives a brief account on in vitro, in vivo screening methods used for assessment of oral bioavailability, and regulatory considerations for the approval.

Bioavailability Enhancement of Coenzyme Q10: An Extensive Review of Patents

Coenzyme Q10 (CoQ10) is a major antioxidant principle found in human body which plays a vital role in maintaining several biochemical pathways of body. It acts as a potential mediator in transferring electrons in oxidoreductive reactions of electron transport chain. Chemically, it is a basic quinone containing moiety having a large and high molecular weight structure. Deficiency of this in body leads to several potential disorders like dysfunctions in cellular energetics, neurological degeneration, higher oxidative stress induced damage, breast cancer etc. The high molecular weight and lipophilicity of CoQ10 makes it poorly water soluble and consequently leads to low systemic availability. Several advancements have been made to enhance the bioavailability of CoQ10 using various approaches like size reduction, solubility enhancement (by solid dispersion, prodrug, complexation, ionization) and use of novel drug carriers such as liposomes, microspheres, nanoparticles, nanoemulsions and self-emulsifying system. The primary objective of the present review is to assemble patents representing the various approaches used for enhancement of CoQ10 bioavailability.

DEVELOPMENT AND VALIDATION OF RP-HPLC METHOD FOR QUANTITATION OF AMOXICILLIN TRIHYDRATE IN BULK AND PHARMACEUTICAL FORMULATIONS USING BOX-BEHNKEN EXPERIMENTAL DESIGN

A rapid and sensitive novel reversed phase-HPLC method with UV detection at 229 nm was developed for routine analysis of amoxicillin trihydrate in bulk drugs and pharmaceutical formulations (Damoxy and Amoxil). Chromatographic separation was performed on a Capacel Pak C18 type MG column using isocratic elution of mobile phase containing mixture of phosphate buffer and methanol (50:50, %v/v) with flow rate at 1.0 ml/min and pH 3.0. The method was validated for linearity (r2 = 0.999), accuracy, precision, sensitivity, system suitability, selectivity, and robustness testing. A 32-factorial design was employed utilizing box-behnken experimental design for the validation of robustness using three factors such as composition of mobile phase (X1), flow rate (X2), pH (X3); while peak area (Y1) and retention time (Y2) were used as responses. System showed minor change in the mobile phase composition and flow rate affects the responses produced, while pH has no significant effect on the responses. Finally the developed experimental design was validated by statistical analysis using ANOVA showed that the proposed method was simple, sensitive, and highly robust for routine analysis of the amoxicillin trihydrate.

Advanced techniques for penetration enhancement in transdermal drug delivery system.

Transdermal route has been recognized as a promising drug delivery system for systemic delivery of drugs and provides the advantage of avoidance of first-pass effect, ease of use, better patient compliance, maintaining constant blood level for longer period of time and decrease side effects. The major pitfalls of this route lie with difficulty in permeation of drugs through the skin. Several literatures have been published for enhancing the permeation of drugs by chemical approaches. However the present review highlighted about the advanced physical techniques used for enhancing delivery of drugs such as structure-based, electrically based, velocity based and several other miscellaneous physical techniques for enhancing the permeation of drugs. In addition to these, the present review also gives an exhaustive account on clinical data about these techniques and regulatory considerations for new drugs as well as generic product approval in transdermal drug delivery.

Nanoparticles for Cancer Targeting: Current and Future Directions

The targeting of pharmaceuticals is a rapidly evolving strategy to overcome the difficulties in therapeutic delivery, especially to the tumor site. Unlike traditional drug delivery systems, nanoparticles based compounds attain superior accretion in the tumor site by their active or passive mechanisms. Due to their exclusive properties like small size, large surface-to-volume ratio, tunable surface chemistry, and the ability to encapsulate various drugs, the nano-sized carriers provide longer circulation time; easy penetration into cellular membranes; efficient site-specific targeting. Recent advancements in polymeric- nanomedicines involve targeting of polymer-based nanoparticles (NPs), micelles, polyplexes, dendrimers, polymersomes, drug/protein conjugates and lipid hybrid systems to tumor pathological site. With different functional moieties, NPs improve the performance in terms of targetability, circulation longevity, enhanced intracellular penetration, stimuli-sensitivity, and carrier-mediated visualization. This review highlighted different preparative techniques and types of nanoparticles in the most recent developments in cancer treatment including promising opportunities in targeted; combination therapy; and other medical and biomedical applications. Various delivery strategies and future prospects of nanoparticles are also enlisted. Apart from that, the review discusses the potential advances and targeting of polymeric nanocarriers within the scope of cancer therapeutic system to emphasize it as an auxiliary tool to the customary drug delivery systems.

Omega-3 fatty acids as pharmacotherapeutics in psoriasis: current status and scope of nanomedicine in its effective delivery.

Psoriasis is a multifactorial autoimmune skin disorder based on irregularities of the T- cell function. The abnormal keratinocyte hyper proliferation in psoriasis arises due to the activation of T-cells which produces rich amount of arachidonic acid leads to generation of various proinflammatory mediators like PGs, LTs, cytokines and adhesion molecules via MAPK/AP-1, EARK1/2 and protein kinase-C (PKCs) activation pathways. Incorporation of naturally occuring bioactives like, omega (ω)-3 fatty acids (i.e., EPA and DHA) in a dose dependent manner results in inhibition of various pro-inflammatory mediators and metabolization of EPA and DHA leads to dampening of inflammation and higher resolution of the skin abnromalities. These all due to the promotion of the synthesis of ω-3 PUFA-derived lipid mediators viz namely resolvins and protectins. These have been widely used alone or in combination with other drugs in the treatment of psoriasis. Despite of their meritorious visages, the use of these bioactives is associated with several hiccups like higher unstability and vulnerable to degradation due to lipid peroxidation, poor and incosistent bioavilability by oral and topical administration. The potential use of nanomedicines in the delivery of such bioactives has gained wider attention owing to their promising bioavailability enhancement characteristics, improved stability and better efficacy. The present review gives an extensive account on ω-3 fatty acids (EPA and DHA) starting from seedling to apex, including biosynthesis, metabolites, and its mechanism of action in psoriasis. Moreover, barriers in the effective delivery of ω-3 fatty acids and how nanomedicines can be fit in the scope of its therapeutic delivery in psoriasis have also been addressed. Despite numerous advantages, application of EPA-DHA as ω-3 fatty acids therapeutics in the management of psoriasis are still at an initial stage. Nanomedicines approach to achieve high bioavailable delivery with safety and stability of ω-3 fatty acids showing the promising area for the future in psoriasis management.