Current Issue : July - September Volume : 2012 Issue Number : 3 Articles : 12 Articles
The aim of the present literature review work was to develop a bilayer floating bioadhesive drug delivery that the immediate release layer system quickly releases drugs and attains onset of action, subsequently floating bioadhesive sustained release layer floats over gastric fluid and releases the drug in sustained or controlled manner. In bilayer tablet formulation, the floating bioadhesive sustained release layer is compressed and immediate release layer is added over it, then both layers are compressed. Tablets are characterized using the official methods. All the above formulations can evaluated for in vitro drug release, buoyancy lag time (BLT), swelling ability, floating behaviour, adhesion retention period, mucoadhesion study....
Circadian rhythms regulate most body functions and are important factors to consider when administering drugs. The existence of circadian rhythms in nature and their influences on human biological systems have given rise to the concept of chronotherapy, which is the science of delivering drugs in a synchronized manner with the rhythm-dependent circadian variation inherent in the human body. Clock genes are the genes that control the circadian rhythms in physiology and behavior. 24h rhythm is demonstrated for the function of physiology and the pathophysiology of diseases. Chronotherapy is especially relevant, when the risk and/or intensity of the symptoms of disease vary predictably over time as exemplified by allergic rhinitis, arthritis, asthma, myocardial infarction, congestive heart failure, stroke, and peptic ulcer disease. Pharmaceutical invention and research are increasingly focusing on delivery systems which enhance desirable therapeutic objectives while minimizing side effects. 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....
Cyclodextrins (CD) are known as the ‘gold standards’ of drug delivery systems. It was discovered about a hundred years ago and took many years to evolve and be accepted to be pharmaceutical additives or excipients. Initially CDs was used mainly for increasing stability of drugs and enhancing the aqueous solubility. Now-a-days, CDs have expanded its ability to form various non-inclusion complexes with drugs to aid in drug delivery. They are able to form aggregates by itself or with various drug combinations. These aggregates are employed in forming encapsulation, nanoparticles and micro-particles. Therefore, CDs are very versatile compounds and has the ability to change the future of drug delivery....
Captopril is an angiotensin converting enzyme inhibitor, widely used in management of hypertension. It has very short half life of 2 h and oral bioavailability of 70%. The present investigation is concerned with the development of the floating microspheres of Captopril to target the drug to its absorption site by increasing the residence time of drug in stomach and to control drug release in therapeutic range for longer period of time. Floating microspheres of Captopril were prepared by Non-aqueous solvent evaporation technique using 32- Full factorial design. In this dosage form, hydrophobic water impermeable polymer Ethyl cellulose (EC) for controlling the release of drug and hydrophobic water permeable polymer (Eudragit RL-100) were used for initial release of drug. Optimization process was carried out with respect to various dependent variables like T50%( h),T80% (h),’n’ of Higuchi eq., Pappas eq., release at 6 h. re, release at 18 h etc. and optimized formulations were developed. Among three optimized formulations, results of OF1, OF2 and OF3 closely met to targeted data. This optimized formulation OF3 consisting of drug polymer ratio 1:6 in which 95 % EC and 5 % Eudragit RL -100. And this optimized formulation has shown the better release of drug upto 88% within 24 h periods of time and around 97 % of microspheres retained buoyant for 24 h .Thus optimized formulation has been developed successfully with desired therapeutic effects....
The present investigation focuses on the preparation and evaluation of non effervescent multiparticulate gastrobuoyant microballoons of lansoprazole by emulsion solvent diffusion method using hydroxypropyl methylcellulose phthalate for enhanced bioavailability. The solvents used in suitable ratio in the preparation are ethyl alcohol and dichloromethane. Optimization studies were carried out by central composite design to study the influence of process and formulation factors on the efficiency of formulations. All the formulations were found be spherical and discrete entities with free flowability. A considerable extent of drug entrapment was attained at lower polymer concentration at a lower stirring rate maintained at 40°C. The drug encapsulation with in the polymeric crust was found to be 81 % against the predicted 75 %. The sphericity and hollow within the microspheres was confirmed by SEM photography. The micromeritic properties indicated better flowability and packability of the spheres. The average particle size of lansoprazole and the formulation LHPMCP-D1 was found to be 135.64 ± 5.22 and 345 ± 32 µm respectively. The in vitro buoyancy was around 94 % with good floatability upto 12 h. In vitro dissolution profile showed prolonged release of drug upto 92 % over 12 h against the predicted 85 % release with non-Fickian diffusion mechanism of drug release. An acute oral toxicity study was done as per OECD guidelines showed no mortality with normal haematological and biochemical values. Histopathogical studies proved the absence of any toxicity. Pylorus ligation method showed that the mean volume of gastric juice for control, pure drug lansoprazole and LHPMCP-D1 was found to be 6.51 ± 0.199, 4.01 ± 0.133 and 4.3 ± 0.07 ml respectively. Free acidity and total acidity for the optimized formulation was found to be 40.83 ± 1.53 mEq/l/100g and 132± 1.33 mEq/l/100g respectively in comparison to 57.66 ± 2.27 and 180.33 ± 1.14 of control animal, 44.83 ± 1.66 and 134.83 ± 1.424 mEq/l/100g of pure drug. An appreciable rise in the pH 5.50 ± 0.051 of LHPMCP-D1 was indicative of the antiulcer activity of the formulation. Residual solvent analysis for dichloromethane and ethanol by gas chromatography was found to be within the limits as prescribed by ICH guidelines for impurities. Long term and accelerated stability studies showed the integrity of drug without any significant change in the physical properties. Thus lansoprazole microballoons with HPMCP proved to be a novel formulation for controlled drug delivery for better bioavailability and patient compliance....
Controlled and sustained drug delivery has become the necessity in modern Pharmaceutical design and an intensive research have been undertaken in achieving much better drug product effectiveness, reliability and safety. This problem has been solved by insitu drug delivery system. In situ forming polymeric formulations are drug delivery systems that are in sol form before administration in the body, but once administered, undergo gelation in situ, to form a gel. They have been of recent interest due to the advantages exhibited by them: sustained and prolonged action in comparison to conventional drug delivery systems, ease of administration and reduced frequency of administration, improved patient compliance and comfort. The formation of gels depends on factors like temperature modulation, pH change, presence of ions and ultra violet irradiation, from which the drug gets released in a sustained and controlled manner. Mainly in situ gels are administered by oral, ocular, rectal, vaginal, injectable and intraperitoneal routes. Hydrogels are presently under investigation as delivery system for bioactive molecules, because of their similar physical properties as that of living tissue, which is due to their high water content, soft and rubbery consistency, and low interfacial tension with water or biological fluids. The article presents a detailed review of these types of polymeric systems, theirevaluation, advancements and their commercial formulations. Various biodegradable polymers that are used for the formulation of in situ gels include gellan gum, alginic acid, xyloglucan, pectin, chitosan, poly (DLlacticacid), poly (DL-lactide-co-glycolide) and poly-caprolactone. Different methods of preparation of hydrogels, novel methods of crosslinking used in the preparation of hydrogels, the mechanism of water transport through the ionic hydrogels, and the release mechanism of the solute from the hydrogels have been mentioned. The production of such devices is less complex and thus lowers the investment and manufacturing cost. These types of polymeric systems, their evaluation, advancements and their commercial formulations have been explained in detail in the article....
The main purpose of this study was to prepare a novel in situ gelling system for oral sustained delivery of Famotidine and study the effect of concentration of gellan gum on various physiochemical characteristics of formulation and also study the effect on drug release from the gel. An ion-activated in situ gel was developed and characterized with gellan gum (0.2%-1%) as a carrier. The formulation contained calcium ions in complexed form, the release of which in the acidic environment of the stomach caused gelation of the gellan gum. As the concentration of gellan gum was increased from 0.2% to 1% the in-vitro release of drug decreased but strength of gel increased. In vitro release characteristics were determined at a receptor solution of pH 1.2 using USP dissolution test apparatus with a paddle stirrer at 50 rpm. In vitro studies demonstrated controlled release of famotidine from the gels for upto 8 hours. Other properties like insitu gelation time, viscosity was also studied. In situ-gelling gellan formulations was successfully developed and It was concluded that prolonged gastro residence time resulting from the in situ gel of famotidine might contribute to better receptor blocking action....
Many drugs are not being effectively and efficiently delivered using conventional drug delivery approach to brain or central nervous system (CNS) due to its complexity. The brain and the central nervous system both have limited accessibility to blood compartment due to a number of barriers. Many advanced and effective approaches to brain delivery of drugs have emerged in recent years. Intranasal drug delivery is one of the focused delivery options for brain targeting, as the brain and nose compartments are connected to each other via the olfactory route and via peripheral circulation. Realization of nose to brain transport and the therapeutic viability of this route can be traced from the ancient times and has been investigated for rapid and effective transport in the last two decades. Various models have been designed and studied by scientists to establish the qualitative and quantitative transport through nasal mucosa to brain. The development of nasal drug products for brain targeting is still faced with enormous challenges. A better understanding in terms of properties of the drug candidate, nose to brain transport mechanism, and transport to and within the brain is of utmost importance. This paper will discuss some pertinent issues to be considered and challenges to brain targeted intranasal drug delivery. A few marketed and investigational drug formulations will also be discussed....
Most compounds face the solubility problems. Hence, with the advancement of chemical science, the need of development of pharmaceutical technologies is also increasing. Pharmaceutical approaches to correct the bioavailability are definitely being cost-effective in comparison with chemical approaches which are also time-consuming. Hence various methods of solubility enhancement are being developed. To overcome the problem of the low solubility of drug, the technique of ‘liquisolid compacts’ is a new and promising approach towards dissolution enhancement. Liquisolid compacts possess acceptable flowability and compressibility properties. The concept of powdered solutions enables one to convert a liquid drug or poorly water-soluble solid drug dissolved in a suitable non-volatile solvent into a dry, non-adherent, free flowing and readily compressible powder by its simple admixture with selected carrier and coating materials and compressed it. Characterization of liquisolid compacts by various methods such as UV/HPLC, Infrared Spectroscopy, Powder X-Ray Diffraction Analysis, Differential Scanning calorimetry, In vitro Dissolution studies, etc....
The impact of nanotechnology in the treatment of Parkinson’s disease (PD) has been briefed in this review. A therapy can be analyzed and optimized only by understanding the pathology of the disease. Among all the drugs of PD therapy, levodopa remains the gold standard. The introduction of levodopa in the late 1960s represented a landmark in the therapy of PD and the remarkable efficacy of levodopa on the akinesia, tremor and rigidity of Parkinson's disease remains incontestable. Nanointervention is necessitated by the fact that only 1% of levodopa crosses the blood-brain-barrier. Nanotechnological application to the PD therapy is a recent advancement and opens up a huge possibility of research and development in this area....
Targeted drug delivery is a method of delivering medication to a patient in a manner that increases the concentration of the medication in some parts of the body relative to others. Targeted drug delivery seeks to concentrate the medication in the tissues of interest while reducing the relative concentration of the medication in the remaining tissues. This improves efficacy of the while reducing side effects. It is very difficult for a drug molecule to reach its destination in the complex cellular network of an organism. Targeted delivery of drugs, as the name suggests, is to assist the drug molecule to reach preferably to the desired site. The inherent advantage of this technique has been the reduction in dose & side effect of the drug. Research related to the development of targeted drug delivery system is now a day is highly preferred and facilitating field of pharmaceutical world. In this manuscript, the attempts that have been made to use either chemical modifications of drugs or the development of drug-nanoparticulate systems to reach these objectives will be reviewed and their advantages and drawbacks discussed, to define what should be the chemical, biophysical, and biological characteristics of an optimized system....
The purpose of the present investigation was to formulate and evaluate the enalapril maleate nail lacquer as preungual drug delivery system for the treatment of hypertension. Enalapril Maleate was chosen as the model drug, and the formulations were prepared with and without polymer Eudargit RL 100 within the concentration range of 1% to 5% (w/v) in the polymeric system. Then, these lacquers were compared for glossiness, film formation, drying rate, smoothness of flow, and nonvolatile content. The in vitro studies were preformed on the artificial membrane in solvent A (phosphate buffer, pH 7.4; and methanol, AR grade, in the ratio of 4:1). The result obtained indicated that the nail lacquer formulation showed good release of the drug. Thus nail lacquers can be used as a successful tool for targeted drug delivery for hypertension....
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