Current Issue : January-March Volume : 2013 Issue Number : 1 Articles : 13 Articles
A new method for the preparation of liposomes is described that avoids the use of pharmaceutically unacceptable solvents and energy-expensive procedures such as Sonication. The method is based on the initial formation of a pro-liposome mixture containing lipid, ethanol and water, which is converted to liposomes by a simple dilution step. Measurements using 6-carboxyfluorescein as a marker indicate that water-soluble drugs can be trapped with extremely high efficiency (65–80% depending on lipid composition)....
Carbon nanotubes (CNTs) are very prevalent in today’s world of medical research and are being highly researched in the fields of efficient drug delivery. Such novel nanomaterials consist of inorganic or organic matter. Carbon nanotubes (CNTs) are allotropes of carbon with a nanostructure that can have a length-to-diameter ratio greater than 1,000,000. They are tubular in shape, made of graphite. CNTs possess various novel properties that make them useful in the field of nanotechnology and pharmaceuticals. Carbon nanotube technology has shown to have the potential to alter drug delivery and biosensing methods for the better, and thus, carbon nanotubes have recently garnered interest in the field of medicine....
Most of the conventional drug delivery systems for treating the colonic disorders are failing as the drugs do not reach the site of action in appropriate concentrations. Colon-specific drug delivery is designed to target drug molecules specifically to this area. Compression coated tablet is one of the approach to target colon and avoid drug release in the gastrointestinal tract. Increasing acceptance of protein- and peptide-based drugs necessitates an investigation into the suitability of various sites for their administration. Colon is being investigated for delivery of such molecules. Development of site-specific delivery systems may exploit a specific property of the target site for drug release. The gastrointestinal tract is occupied by over 400 bacterial species, each having a specific role in the tract. Colon, the distal part of the intestine is inhabited by a large variety of gram negative microflora. This flora produces a vast number of enzymes which are being exploited for formulation of colon-specific drug delivery systems. A number of microbially activated systems for colon-specific drug delivery are being evaluated. In compression coated tablet core tablet is coated with coating material which is degraded by enzyme in the colon. These include prodrugs and synthetic or natural polymer-based delivery systems. This article aims at reviewing the various microbially activated drug delivery systems for colon-specific drug delivery with specific reference to the microflora of the various segments of the gastrointestinal tract and their role in targeting drug delivery to the colon. In this article natural polymers are given that are used for compression coating with their role....
Dental inserts of ofloxacin were prepared with objectives of maintain the effective concentration of drug in gingival pocket for prolong period of time and to treat the gingivitis. Biodegradable ofloxacin films were prepared by solvent casting method. The biodegradable inserts were evaluated for drug-excipients interaction, physico-chemical characteristics, polymer degradation, biodegradation of inserts in enzymatic action and in vitro release studies. The weight and thickness of the inserts were in the range of 54.0-59.7 mg and 94.9-95.6 microns, respectively for different formulations. The drug content varied from 10.2-11.4 mg. the biodegradation was evaluated by enzymatic condition. The influence of rate-controlling membrane of different biodegradable polymers of PCL and PLA on release kinetics was studied. The drug release for prepared formulations with rate-controlling membrane of PCL and PCL was found to be 74.10-75.2 and 79.64-80.92 % respectively and followed zero-order kinetics. PCL-ofloxacin biodegradable inserts are promising delivery for treatment of gingivitis for prolong period....
The objective of present work was to develop the matrix tablets of capcitabine using natural polymers, guar gum and xanthan gum, for colon specific drug delivery and sustained release. The tablets were prepared by wet granulation technique which will provide the sustained release of the drug; various concentrations of the polymer were used to optimize the formulation. The influence of buffer pH and drug/polymer ratio on the drug release was studied. The in-vitro drug release studies were performed in HCl buffer pH 1.2 and Phosphate buffer pH 7.4. Relatively slow release of drug was seen from formulation having matrices containing optimum concentration of xanthan gum and guar gum. Accelerated stability studies were also carried out following ICH Guidelines. The results of 32 factorial full factorial designs shown that the polymer: drug ratio and type of polymer affects the rate of drug release....
The present study involves the ionic gelation of alginate molecules which offers a flexible and easily controllable process for the manipulating the characteristics of the beads which is important in controlling the release rate and consequently the absorption of Gliclazide from the GIT, variation in polymer, concentration, time of gelation in the external phase were examined systemically for their effects on rate release and entrapment efficiency by Plackett Burman’s factorial design. The swelling behavior strongly depends on the polymer concentration....
Freeze-dried (lyophilised) wafers and solvent cast films from sodium alginate (ALG) and sodium carboxymethylcellulose (CMC) have been developed as potential drug delivery systems for mucosal surfaces including wounds. The wafers (ALG, CMC) and films (CMC) were prepared by freeze-drying and drying in air (solvent evaporation) respectively, aqueous gels of the polymers containing paracetamol as a model drug. The porous freeze-dried wafers exhibited higher drug loading and water absorption capacity than the corresponding solvent evaporated films. Moisture absorption, ease of hydration and mechanical behaviour were affected by the polymer and drug concentration. Two polymorphs of paracetamol were observed in the wafers and films, due to partial conversion of the original monoclinic to the orthorhombic polymorph during the formulation process. The results showed the potential of employing the freeze-dried wafers and solvent evaporated films in diverse mucosal applications due to their ease of hydration and based on different physical mechanical properties exhibited by both type of formulations....
In this article the polymers which are used in drug delivery are mentioned polymers are mainly natural and synthetic in nature. These have the property to entrap the bioactive agents because of its matrix formation property, which able to reaches the drug towards targeted sites in optimum amounts. Polymers are applicable in targeted drug delivery and also act rate controlling material in pharmaceutical formulation. Selection of polymer in formulation depends upon the bulk and surface properties of polymer like molecular weight, adhesion, solubility, hydro-philicity, lubricity, surface energy and smoothness....
Cinnarizine is an ideal candidate for incorporation in a controlled release device to diminish its adverse effects after oral administration. Microspheres were prepared by using ethyl cellulose as a polymer and CaCl2 as a cross-linking agent. In this investigation, a 32 full factorial design was applied to investigate the combined effect of two formulation variables, each at 3 levels and the possible 9 combinations of cinnarizine microspheres were prepared. The amount of Ethyl cellulose (X1) and the amount of PVA (X2) were taken as independent variables. The entrapment efficiency is taken as dependent variables. Contour plots are presented to visualize the impact of independent variables on the entrapment efficiency in the microspheres. It was observed that entrapment efficiency was dependent on both the factors. The entrapment efficiency is influenced by the change in the EC ratios. The diameter of the microspheres showed poor correlation with the selected independent variables. All the batches yielded microspheres with excellent topographical characteristics. The entrapment efficiency for the 9 batches showed a wide variation (ie, 16.39% and 54.17%). The diameter of the microspheres was not found to be dependent on the type and amount of polymers used for the preparation of microspheres. The diameter range of the prepared microspheres was 321.02 µm to 484.35 µm. Five kinetic models including the zero order, first order, Higuchi matrix, Korsmeyer Peppas and Hixson Crowell release equations were applied to process the in-vitro release data to find the equation with the best fit. All the formulations follow the Higuchi equation. Hence, the release is through diffusion mechanism. The results of analysis of variance test, for drug content in microspheres, indicated that the test is significant. The drug was released by diffusion of anomalous type. Acceptable batches were identified in the experimental design with constraints on percentage drug released....
Pulsatile drug delivery systems (PDDS) are gaining importance in the field of pharmaceutical technology as these systems deliver the right dose at specific time at a specific site. It is gaining increasing attention as it offers a more sophisticated approach to the traditional sustained drug delivery i.e. a constant amount of drug released per unit time or constant blood levels. Pathophysiological need of the disease, resulting in improved patient therapeutic efficacy and compliance. Diseases wherein PDDS are promising include asthma, peptic ulcer, cardiovascular diseases, arthritis, attention deficit syndrome in children, and hypercholesterolemia. In addition, time-based colonic release can be attained when pulsatile delivery systems are properly adapted to overcome unpredictable gastric emptying and provide delay phases that would approximately match the small intestinal transit time. The current article focuses on the diseases requiring PDDS, methodologies involved for the existing systems, recent update on pulsatile drug delivery system....
Pulsatile drug delivery system is most important now a day as it release the drug in a planned pattern at specific time as per the pathophysiological need of the disease resulting in improved patient compliance and therapeutic efficacy. This system is designed for chronopharmacotherapy, which is based on circadian rhythm. The basic principle for the use of pulsatile release is for the drugs where a constant drug release, i.e., a zero-order release is not preferred. Ideally, with a pulsatile system, the drug is released rapidly and transient after a defined lag time of no drug release. Some of the disease conditions wherein PDDS are promising include duodenal ulcer, cardiovascular diseases, arthritis, asthma, diabetes, neurological disorder, cancer, hypertension and hypercholesterolemia. Different approaches are designed based on capsular, osmotic, single and multiple unit systems that are modulated by soluble or erodible polymer coatings, rupturable membranes, pH-sensitivity, time-dependency (lag time), etc to formulate the different dosage forms like tablets, capsules, multiparticulates, microspheres, liposomes. Our aim in this review is to outline the rational and prominent design strategies behind site-specific oral pulsatile delivery. Marketed product like Pulsicap®, Cardizem® and Pulsys® are based on pulsatile release system....
With the advancement in the field of chronobiology, modern drug delivery approaches have been elevated to a new concept of chronopharmacology. Twenty-four hours rhythms are demonstrated for the function of physiology and the pathophysiology of diseases. Such chronopharmacological phenomena are influenced by not only the pharmacodynamics, but also the pharmacokinetics of medications. The underlying mechanisms are associated with the 24-hour rhythms of biochemical, physiological, and behavioral processes under the control of the circadian clock. New technology for delivering medications precisely in a time-modulated fashion is being developed to manage human diseases. From the point of view of pharmaceutics, the application of a biological rhythm to pharmacotherapy may be accomplished by the appropriate timing of conventionally formulated tablets and capsules, and a special drug delivery system, to synchronize the drug concentrations with the rhythms in the disease activity. Therefore, the present article gives an overview of the dosing time-dependent alterations in the therapeutic outcome and safety of the drug. The underlying mechanisms and usefulness are introduced from the point of view of chronopharmacology and chronotherapy....
Phytosome one type of Vesicular Drug Delivery System. This one kind similar modified vesicular drug delivery of Liposome. Common phytosome mean two term phyto mean plant and some mean cell like.In phytosome herb extracts conversion is novel formulation that cause increase Bioavalibity. Created bond between Phosphatidyl choline and plant component and shown better stability of Phytosome. In phytosome, advanced forms of herbal products that are better absorbed, utilized and as a result produce better results than conventional herbal extracts. Most of the phytosomal studies are focused to Silybum marianum which contains premier liver-protectant flavonoids and which improving the solubility of bile to herbal constituent. In gererally Phytosome is Significantly greater clinical benefit. The outcome of this review is that Phytosome represents a promising vesicular drug delivery system to delivers therapeutic compounds for a range of possible application....
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