Current Issue : July - September Volume : 2010 Issue Number : 2 Articles : 13 Articles
In this study efforts were made to design matrix tablet containing superporous hydrogel particles (SPHPs) for sustained delivery of Ranitidine hydrochloride. The SPHPs were prepared from superporous hydrogel of poly(AM-co-AA). The characterization studies for SPH were performed by measurement of apparent density, porosity, swelling studies, and scanning electron microscopy (SEM) studies. SEM images clearly indicated the formation of interconnected pores, and capillary channels. The SPHPs were found to be low dense, highly porous and highly swellable. The prepared tablet floated and delivered the Ranitidine hydrochloride for about 12 hour. To ascertain the kinetics of drug release, the dissolution profiles were fitted to mathematical models that include zero-order, first-order, Higuchi, Hixson-Crowell, Korsmeyer-Peppas, Weibull, and Hopfenberg. The in vitro drug release from proposed system was best explained by the Hopfenberg model indicating that the release of drug from tablets displayed heterogeneous erosion. It is concluded that the proposed gastroretentive drug-delivery system based on SPHPs is promising for stomach specific delivery of Ranitidine hydrochloride....
The aim of the present study is to develop a delivery system wherein the gastric retention would be achieved for Cefpodoxime which is mainly absorbed in the upper part of the gastrointestinal tract and the unabsorbed fraction, which arrives to the colon in conventional dosage forms, may cause serious local side effects may be avoided. Therefore gastroretentive drug delivery system is an excellent solution to reduce the appearance of such drugs in the colon. Matrixes of different polymer ratio Cefpodoxime were prepared by direct compression method. The major objective of the present investigation was to develop a gastroretentive drug delivery system containing Cefpodoxime using differnt polymer ratio by direct compression technique.\r\nThe drug kinetic release of Cefpodoxime was fitted to different models based on coefficient of correlation (r). All the formulations, except A2, A3 and A6 showed Korsemeyer-Peppas model as the best fit model. Formulation A2 and A3 showed first order model while A6 showed zero order model. Diffusion exponent (n) value was found in the range of 0.52-0.99 indicating diffusion as a release mechanism. The swelling studies of all the formulations showed that formulations containing Xanthan gum has higher swelling indices than HPMC K100M and HPMC K4M. It can be concluded that formulations having higher swelling retarded the release of drugs more than those with lower swelling....
We report a novel soft lithography based technique to microfabricate non-spherical biodegradable polymeric microparticles of different sizes and shapes as drug delivery systems. Geometrical control over the shape and size of these microparticles renders them different aerodynamic and fluidic dynamic properties when compared to conventional spherical microparticles and may prove to be beneficial in certain drug delivery strategies, such as pulmonary and intravenous routes. Microparticles may also be used in the delivery of vaccines and molecules such as DNA for use in gene therapy. Various techniques are described as fabrication methods for micro/ nanoparticles are solvent evaporation and extraction based processes like single emulsion process and double emulsion process, phase separation method, spray drying method. Particle size is a critical parameter for several aspects of controlled drug delivery including control of drug-release kinetics, passive targeting to specific cell or tissue types, biodistribution upon administration and available routes of administration. In conclusion, the uniform, biodegradable polymeric microparticles produced have potential to be used in a variety of drug delivery applications and polymer-based microfabrication technology holds promise to produce sophisticated, multi-functional drug delivery devices. Many disease states, that are currently incurable, can potentially be cured using these new therapies if the barriers to their delivery are overcome....
A controlled release system was developed using film coating as drug release controlling system, ketoprofen was used as model drug. The drug was prepared in tablets containing 15% Gelucire 50/13 as matrix forming material, and then it was film coated with ethylcellulose (300cps). The in vitro dissolution studies showed that the rate of ketoprofen release was sufficiently sustained for up to 8 hours with coating thickness 0.04 mm, and this was found to be comparable with the commercial reference preparation (Oruvail CR 100 mg) in terms of the release profile and extent of drug release. A 12 hours sustained release profile was achieved with coating thickness 0.06 mm. Thermal study of ketoprofen with each individual excipient at a ratio of 1:1 showed that ketoprofen has decreased in its melting endothermic characteristics with Gelucire 50/13, PVP (K30), and magnesium stearate, which was due to the lost of water (dehydration), while there were no changes in the melting point of ketoprofen with ethylcellulose and lactose. The absence of the melting endothermic characteristics of ketoprofen in the tablet indicates a strong interaction but does not necessarily of incompatibility. The FTIR studies showed that the ketoprofen functional groups were stable and did not have any interactions with any excipients in the form of physical mixture as well as in the form of tablet....
Metformin hydrochloride is recommended globally as first line therapy due to its favorable profile on morbidity and mortality associated with type-2 diabetes mellitus. However, limitations of multiple dosing and risk of triggering gastrointestinal symptoms make its dose optimization difficult. The present study was designed to develop an oral sustained release metformin hydrochloride tablet by using synthetic hydrophilic Edragit RLPO alone or in combination with hydrophobic natural polymers Gum copal and Gum damar, as rate controlling factor. The in-vitro dissolution study was carried out using USP 22 apparatus II, paddle method. The drug release study revealed that Edragit RLPO alone was able to sustain the drug release only for 8 h (93.697% �± 1.18% release). Combining Edragit with Gum copal and Gum damar sustained the drug release for 12 h (93.517 % �± 0.60% and 89.710 % �± 0.42 % release respectively). Kinetic modeling of in-vitro dissolution profiles revealed the drug release mechanism ranges from diffusion controlled or Fickian transport to anomalous type or non-Fickian transport. Applying Korsmeyer equation to in-vitro drug release data indicated that diffusion along with erosion could be the mechanism of drug release....
To develop formulation for effective management of treatment of various fungal disease caused by Candida species, ketoconazole, a broad-spectrum imidazole antifungal drug with a very short half life (2 hour) coated with Eudragit S 100 and Eudragit RL 100 technique to enhance effective prolong drug release for delivery in stomach. Microspheres with an internal hollow structure were prepared by a Novel quasi emulsion diffusion method and were investigated. Ketoconazole could be coated with Eudragit S 100 and Eudragit RL 100 with an entrapment efficiency of 70.12%. Spherical, transparent and free flowing hollow microspheres were obtained. Scanning electron microscopy revealed the spherical structure under the magnification of 200 �µm. The FTIR and DSC analysis indicated the stability and compability of drug in Eudragit S 100 and Eudragit RL100 microspheres. The microspheres were in the suitable particle size range of 421 to 660�µm. No appreciable difference was observed in the stability study, in the extent of degradation of product for 60 days in the microspheres that were stored at various temperatures. In vitro and in vivo release study showed that ketoconazole release from all formulation was also slow and controlled release....
The purpose of this investigation was to increase the gastric residence time of Glipizide, an oral anti-diabetic drug, which is weakly acidic in nature and has absorption window in the gastric region. Gastro retentive drug delivery system of Glipizide was prepared as floating matrix tablets by employing different grades of HPMC, Sodium CMC and Methyl Cellulose using both effervescent and non-effervescent techniques. Sodium bicarbonate was incorporated as a gas-generating agent and the effect of concentration of citric acid on floating properties was investigated. The ratio of polymer was optimized to achieve required buoyancy for the tablets. The formulated tablets were evaluated for uniformity of weight, hardness, friability, drug content, in-vitro buoyancy and dissolution studies by USP type-II method and modified beaker method. The selected formulations exhibited satisfactory physico-chemical characteristics and showed good in-vitro buoyancy for up to > 24 hrs. The integrity of the matrix tablet and stability was good and also showed sustained drug release. The effect of hardness on floating behavior of the tablets was evaluated. The release kinetics of the tablets was studied to predict the mechanism of drug release in-vitro. The in-vivo x-ray study was performed in the healthy male rabbits, to prove the floating behavior of the tablets. The appearance of the tablets in the upper part of the stomach and its position confirmed the in-vivo floating behavior....
Rofecoxib is one of the most potent nonsteroidal anti-inflammatory agents for the treatment of pain and inflammation associated with musculoskeletal disorder, primary dysmenorrhea, rheumatoid arthritis and osteoarthritis. However, the oral administration of rofecoxib is inconvenient due to its gastric ulcerogenic activity and systemic cardiac toxicities. The topical administration may help in the localized delivery with improved availability of the drug at the site of action and in turn, reduce the dose and dose-dependent side effects. The purpose of the present investigation is to encapsulate rofecoxib in niosomes and incorporate the prepared niosomes into the dermal gel base for sustained therapeutic action. The entrapment efficiency of rofecoxib in niosomes was optimized by altering the proportion of nonionic surfactant (Span 20, Span 40 and Span 60) and cholesterol. The mean niosomes sizes were in the range of 10.16�±1.17 to 11.94�±1.24 ?m. The drug-leakage study carried out at different temperature of 4�±20 C and 25�±20 C for a period of two months affirms that the drug leakage increased at a higher temperature. The ex vivo permeation study using pig ear skin shows slower permeation with niosomal gel (20.93 ?g/cm2/h) as compared with the plain drug gel (55.26 ?g/cm2/h), ointment base (29.70 ?g/cm2/h) and cream base (46.09 ?g/cm2/h). The lower ex vivo flux value with niosomal gel indicates the prolong drug release behavior with sustained therapeutic action....
Nanotechnology, the creation and utilization of materials, devices and systems through the control of matter on the nanometer has been applied to molecular diagnostics. Cancer is caused by damage of genes which control the growth and division of cells. Detection, diagnosis and treatment are possible by confirming the cancerous growth in the cells, rectifying the mechanism that is responsible for the damage caused in the genes and by interfering with the blood supply to these cells or by destroying them. Cancer is the leading cause of death in the World among all populations across different age groups. For the first time cancer has surpassed heart disease as in the number of deaths reported due to the disease. This worrisome statistic has resulted not from an increase in the incidence of cancer, but because deaths from heart disease have dropped nearly to half. It is a matter of deep concern to the world in general and scientific community in particular that the number of cancer-related deaths has remained about the same in the last decade. This fact accentuates the need for a new generation of more effective therapies for cancer and their successful launch in the world market. In this review, the details of newer treatment methods using nanotechnology are discussed....
The aim of the present investigation was to prepare bioresponsive delivery systems of Moxifloxacin Hydrochloride for ophthalmic use which are in liquid state under storage conditions and turn into a gel upon instillation into the eye. Various polymers which undergo phase transition upon change in temperature and/or pH were used to prepare the formulations. The prepared formulations were characterized for drug content, clarity, transparency, pH, in-vitro drug release. Ocular irritancy potential of the optimized formulation was tested using HET CAM test. In-vivo studies were performed using rabbits to evaluate the ocular irritation potential and precorneal residence time of the prepared formulation. The prepared formulations exhibited all the desired characteristics such as optimum drug content, pH, transparency and lack of irritation. The formulations were also able to withstand sterilization by autoclaving and were found to be stable on storage. The ocular retention time of the prepared formulations was significantly higher than that of the marketed preparation. Phase transition systems of Moxifloxacin Hydrochloride seem to be promising in enhancing the precorneal residence time and thus reducing the frequency of administration....
Pharmaceutical research and invention started focusing increasingly on delivery systems which enhance desirable therapeutic objectives minimizing the side effects. Multiparticulate drug delivery system (MDDS) is composed of small beads and each small bead further composed of many layers of drug substance and rate-controlling polymers. Recent trends suggest that MDDS are especially suitable for achieving controlled or delayed release with low risk of dose dumping, reproducible, flexibility of blending to attain different release patterns as well as short gastric residence time. The various release profiles like sustained release, time delayed release, and pulsatile release of active pharmaceutical ingredients can be achieved using this approach. The duration of drug release following the lag time depends on the composition and thickness of the polymer barrier and the coating itself. The multiparticulate system provides optimal release profiles for either single drug or for a combination of drugs. Consequently, multiparticulate drug delivery systems provide tremendous opportunities for designing new controlled and delayed release oral formulations, thus extending the frontier for future pharmaceutical development. The present review is an attempt to give the detail insight of various designs and technologies which have been tried in the formulation of MDDS....
The present study was aimed to design an in-situ ophthalmic gel formulation of timolol maleate containing combination of pH induced gelling agent i.e. carbopol 934P and thermo-sensitive gelling agent i.e. methyl cellulose A4M and to evaluate the effect of methyl cellulose A4M upon addition to carbopol 934P with respect to rheological characteristic. Brookfield viscometer LV-I model is used to check the rheological behavior. Addition of methyl cellulose to carbopol 934P increases the viscosity of system that is why because methyl cellulose works as a viscolizer and thus the release of drug from gel is retarded. After evaluation it was found that the combination of both the polymer shows the thixotrophic behavior which is an acceptable criterion to perform better in the ocular system and also acceptable as these systems prove less irritation to the cornea. As a complementary to rheological evaluation, the in-situ gel is further evaluated for in-vitro release study and statistical data analysis. The best fit model with highest correlation coefficient was shown in Higuchi�s model. The regression value is closer to unity (R2 = 0.9949). The system also shows the sustained drug delivery system and follows the fickanian diffusion which shows that the drug release from the in-situ ocular drug delivery system is diffusion controlled; it has the advantages over the eye drop solution which are instilled in eyes or to apply gel or ointment formulation in to the eyes....
Trazodone Hydrochloride (TZN), a serotonin uptake inhibitor, is used in the treatment of moderate to severe depression in schizophrenic patients. The undesirable side effects of TZN administered orally can be offset by using the transdermal route, which attenuates the fluctuating TZN levels (52 ââ?¬â?? 81 %) resulting from oral therapy. The present study is aimed for ex vivo and in vivo biopharmaceutical evaluation of transdermal matrix patch of TZN in rabbits. The TZN patch was prepared by solvent evaporation technique using Eudragit RL 100 and RS 100 polymers with triethylcitrate (plasticizer) and fennel oil (permeation enhancer). The ex vivo patch evaluation was performed using Keshary-Chien transdermal diffusion cell with mouse and human cadaver epidermis as membrane. TZN transdermal absorption from patch was compared to that from peroral TZN solution in rabbits. The steady-state skin permeation rate of 134.09 Ã?± 249 ?g/cm2/h and 135.75 Ã?± 1.18 ?g/cm2/h was achieved across mouse and human cadaver epidermis, respectively. The steady-state transdermal TZN concentration of 2.3 ?g/ml was achieved in rabbits after an initial lag time of ~ 2 h. the Cmax of peroral TZN solution was calculated to be 5.84 ?g/ml at a Tmax of 2 h indicating its rapid absorption compared to the transdermal administration with a Tmax of 5 h. The transdermal TZN bioavailability in rabbit is calculated to be 32 %. The ex vivo and in vivo biopharmaceutical parameters were in good agreement with respect to input rate, steady state plasma TZN concentration and lag time. The higher steady state blood concentration in rabbit than the effective blood concentration is expected to appear at 0.017 ?g/ml in human with a higher clearance value than that in rabbits. It can be estimated that a transdermal patch of about 40 cm2 containing 4 mg/cm2 of TZN is likely to be able to attain and maintain the therapeutic concentration (0.75 ?g/ml) of TZN over a period of 24 h and even further....
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