Current Issue : October - December Volume : 2011 Issue Number : 4 Articles : 12 Articles
Nanooncology, the application of nanobiotechnology to the management of cancer, is currently the most important chapter of nanomedicine. Nanobiotechnology has refined and extended the limits of molecular diagnosis of cancer, for example, through the use of gold nanoparticles and quantum dots. Nanobiotechnology has also improved the discovery of cancer biomarkers, one such example being the sensitive detection of multiple protein biomarkers by nanobiosensors. Magnetic nanoparticles can capture circulating tumor cells in the bloodstream followed by rapid photoacoustic detection. Nanoparticles enable targeted drug delivery in cancer that increases efficacy and decreases adverse effects through reducing the dosage of anticancer drugs administered. Nanoparticulate anticancer drugs can cross some of the biological barriers and achieve therapeutic concentrations in tumor and spare the surrounding normal tissues from toxic effects. Nanoparticle constructs facilitate the delivery of various forms of energy for noninvasive thermal destruction of surgically inaccessible malignant tumors....
Gellified emulsion (emulsion in gel) have emerged as one of the most interesting topical drug delivery system as it has dual release control system i.e. emulsion and gel. Also stability of emulsion is increased when it is incorporated in gel. They have a high patient acceptability since they possess the advantages of both emulsions and gels. Apart from physicochemical evaluation during development of topical preparation, it is must to check the material and method which ensures the sterility and also needful to analyze that the preservative used in the formulation is efficient. The present work is to confirm that the material and method used for preparation of ibuprofen emulgel doesn’t impart any microbial contamination and the preservative methyl paraben 0.25 % used is sufficient to prevent the microbial attack for this formulation. The preservative efficiency test and microbial contamination test were carried....
Soft contact lenses can improve the bioavailability and prolong the residence time of drugs and, therefore, are ideal drug carriers for ophthalmic drug delivery. Hydrogels are the leading materials of soft contact lenses because of their biocompatibility and transparent characteristic. In order to increase the amount of load drug and to control their release at the expected intervals, many strategies are developed to modify the conventional contact lens as well as the novel hydrogel contact lenses that include (i) polymeric hydrogels with controlled hydrophilic/hydrophobic copolymer ratio; (ii) hydrogels for inclusion of drugs in a colloidal structure dispersed in the contact lenses; (iii) ligand-containing hydrogels; (iv) molecularly imprinted polymeric hydrogels; (v) hydrogel with the surface containing multilayer structure for drugs loading and releasing. The advantages and disadvantages of these strategies in modifying or designing hydrogel contact lenses for extended ophthalmic drug delivery are analyzed in this paper....
Sustained and Prolonged drug delivery approaches are very common in today’s Pharmaceutical formulation design and research work is still going on in achieving better drug product. Ophthalmic use of viscosity-enhancing agents, penetration enhancers, cyclodextrins, prodrug approaches, ocular inserts and the ready existing drug carrier systems along with their application to ophthalmic drug delivery are very common to improve ocular bioavailability. Amongst these hydrogel (insitugel forming) systems are of very important. They help to increase in precorneal residence time of drug to a sufficient extent that anocular delivered drug can exhibit its maximum biological action. The concept of this innovative ophthalmic delivery approach is to decrease the systemic side effects and to create a more pronounced effect with lower doses of the drug. Many polymers are very useful with majority of hydrogels, which undergo reversible sol-gel phase transitions in the ocular cul-de-sac to form viscoelastic gels due to phase changes of polymers in response to the physiological environment (temperature, pH and presence of ions in organism fluids. These insitu forming gels can be applied as solution and exhibit pseudo plastic behavior to minimize interference with blinking, increase precorneal residence of the delivery system and enhanced ocular bioavailability....
The prolonged residence of drug formulation in the nasal cavity is of utmost importance for intranasal drug delivery. The objective of the present investigation was to develop a mucoadhesive in situ gel with reduced nasal mucocilliary clearance in order to improve the bioavailability of the antiemetic drug, Domperidone maleate. The in situ gelation upon contact with nasal mucosa was conferred via the use of the thermogelling Pluronic flake 127 whereas mucoadhesion and drug release enhancement were modulated via the use of sodium alginate and polyethylene glycol polymers respectively. The results revealed that the mucoadhesive polymer increased the gel viscosity but reduced its sol gel transition temperatures and the drug release. The inclusion of polyethylene glycol polymer counteracted the effect of mucoadhesive polymer where by it decreased the gel consistency and increased the sol gel transition as well as in vitro drug diffusion. The in vitro tests performed for mucoadhesive strength and drug diffusion showed that nasal in situ gelling formulations prepared are having good mucoadhesive strength with nearly100% drug diffusion within 4 hours. So this study points to the potential of mucoadhesive in situ nasal gel in terms of ease of administration, accuracy of dosing, prolonged nasal residence and improved nasal bioavailability....
In the preparation of final dosage form of a drug, it is necessary to disperse the drug in a biologically inert matrix such as polymeric matrices or clay particles, for improved drug delivery. In these cases it is necessary to produce systems that not only release the drug at an appropriate rate but also have suitable mechanical properties for the particular application. To optimize biological activity and therapeutic effect of the drug, the drug delivery compositions with modified release systems are developed where the drug is released at a controlled rate such as the controlled release oral drug delivery systems. Clay minerals like montmorillonite, rectorite find wide range of applications, in various areas of science, like drug delivery systems due to their natural abundance and the propensity with which they can be chemically and physically modified to suit practical technological needs. Montmorillonite has been extensively applied for prolonged release of drugs as it can retain large amounts of drug due to its high cation exchange capacity. It may interact with active drug molecules, but also with inactive components like polymers. On the basis of these interactions, montmorillonite and its modified forms can be effectively used to modify drug delivery systems. This review emphasizes the modifications of montmorillonite clay, its interactions with drug molecules and its applications in novel nanoparticulate drug delivery systems....
Nitric oxide (NO) is a promising pharmaceutical agent that has vasodilative, antibacterial, and tumoricidal effects. To study the complex and wide-ranging roles of NO and to facilitate its therapeutic use, a great number of synthetic compounds (e.g., nitrosothiols, nitrosohydroxyamines, N-diazeniumdiolates, and nitrosyl metal complexes) have been developed to chemically stabilize and release NO in a controlled manner. Although NO is currently being exploited in many biomedical applications, its use is limited by several factors, including a short half-life, instability during storage, and potential toxicity. Additionally, efficient methods of both localized and systemic in vivo delivery and dose control are needed. One strategy for addressing these limitations and thus increasing the utility of NO donors is based on nanotechnology....
Nanotechnology is a tremendous field in the medicine. Nanosuspensions have emerged as a promising strategy for the effective delivery of hydrophobic drugs because of their unique advantages and versatile features. Most of the newly discovered drugs coming out from High-throughput screening in drug are failing due to their poor water solubility. Nano refers to particles size range of 1-1000nm. Due to solubility is a crucial factor for drug effectiveness, it is a challenging task to formulate any poorly soluble drug in the industry in conventional dosage forms. Critical problem for poorly soluble drugs is too low bioavailability and erratic absorption. The problem is even more complex for drugs belonging to Biopharmaceutical classification system (BCS) CLASS II category, such as Carbamazepine and itraconazole, as they are poorly soluble in both aqueous and nonaqueous media, and for those drugs having a log P value of 2. To date, nano technology for drug delivery has gained much interest as a way to improve the solubility as well as bioavailability of poorly soluble drugs. Reduction of drug particles up to sub micron level leads to a significant increase in dissolution rate with enhanced bioavailability. Nonosuspensions are promising candidate for poorly soluble drug to enhance the dissolution. Nanosuspensions are submicron colloidal dispersion of pharmaceutical active ingredient particles in a liquid phase without any matrix material, stabilized by surfactants. Nanosuspensions are prepared by using wet mill, emulsion-solvent evaporation, high pressure homogenizer, super critical fluid techniques and melt emulsification method. A nanosuspension not only resolves the poor solubility and bioavailability problems but also alters the pharmacokinetic parameters of drug and thus improves drug safety and efficacy. The review article includes methods of pharmaceutical nanosuspension production, formulation, characterization, application and evalution in drug delivery as well as the marketed products....
Flavonoids and its related phenolic compounds have found to have antioxidant, anti-inflammatory, anti cancer, weight loss, circulation management and hepatoprotective properties but owing to their polar nature they have poor absorption which ultimately lead to their poor systemic bioavailability, thereby their therapeutic efficacy gets reduced. Phytosome – a phytolipid delivery system can surpass these drawbacks .phytosomes are phospholipid-substrate complex in which there occurs the formation of weak hydrogen bonds between the polar portion while the non polar tail of phospholipid wraps over the complex thereby imparting lipophilic character to it and hence increases its absorption. Phytosomes differs from liposomes to greater extent. The commercial production of phytosomes is easy. Characterization techniques are available which makes them to readily usable drug delivery system....
Liposomal formulations were significantly explored over the last decade for the ophthalmic drug delivery applications. These formulations are mainly composed of phosphatidylcholine (PC) and other constituents such as cholesterol and lipid-conjugated hydrophilic polymers. Liposomes are biodegradable and biocompatible in nature. Current approaches for topical delivery of liposomes are focused on improving the corneal adhesion and permeation by incorporating various bioadhesive and penetration enhancing polymers. In the case of posterior segment disorders improvement in intravitreal half life and targeted drug delivery to the retina is achieved by liposomes. In this paper we have attempted to summarize the applications of liposomes in the field of ophthalmic drug delivery by citing numerous investigators over the last decade....
: Oral route has always been preferred and most convenient route for drug administration. The major problem associated with oral route of drug administration is low bioavailability, which is due to poor aqueous solubility of drug entity. Approximately 35-40% of new drug entities exhibit poor aqueous solubility and present a major challenge to modern drug delivery system, because of their low bioavailability. For the improvement of bio-availability of drugs with such properties requires various pharmaceutical strategies including solid dispersions, cyclodextrines complex formation, and co-precipitation. Recently self emulsifying drug delivery system has gained more attention due to enhanced oral bio-availability and reduction in drug dose.\Self-Emulsifying Drug Delivery System is isotropic mixture of oil, surfactant, solvent, and co solvent. The principal characteristic of these systems is their ability to form fine oil-in-water emulsions or micro-emulsions upon mild agitation following dilution by an aqueous phase....
Transfersomes are a form of elastic or deformable vesicle, which were first introduced in the early 1990s. Elasticity is generated by incorporation of an edge activator in the lipid bilayer structure. The original composition of these vesicles was soya phosphatidyl choline incorporating sodium cholate and a small concentration of ethanol. Transfersomes are applied in a non-occluded method to the skin and have been shown to permeate through the stratum corneum lipid lamellar regions as a result of the hydration or osmotic force in the skin. They have been used as drug carriers for a range of small molecules, peptides, proteins and vaccines, both in vitro and in vivo. Transfersomes possess an infrastructure consisting of hydrophobic and hydrophilic moieties together and as a result can accommodate drug molecules with wide range of solubility. They can act as a carrier for low as well as high molecular weight drugs e.g. analgesic, anesthetic, corticosteroids, sex hormone, anticancer, insulin, gap junction protein, and albumin....
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