Current Issue : October-December Volume : 2011 Issue Number : 4 Articles : 7 Articles
The purpose of writing this review on gas powered systems (GPS) was to compile the recent literature with special focus on the principal mechanism of floatation to achieve gastric retention. The recent developments of Gas Powered System (GPS) including the physiological and formulation variables affecting gastric retention, approaches to design single-unit and multiple-unit floating systems, and their classification and formulation aspects are covered in detail. Drugs with narrow absorption window in the gastrointestinal tract have poor absorption. Therefore the gas powered system have been developed, which prolong the gastric empting time. The improved controlled drug delivery system of the present invention is designed to deliver effectively a drug to a patient over a specific time period (temporal control) and from particular portion of the patients gastrointestinal tract (spatial control).the improved controlled drug delivery system avoids dose dumping and results in the most therapeutic administration of a particular drug to a particular person with a particular ailment to improved the bioavaibility. These systems are useful to several problems encountered during the development of a pharmaceutical dosage form....
The objective of the present study was to develop simple fast disintegrating tablets of Rosiglitazone for improving patient compliance, especially paediatric and geriatric categories by effervescent method. Croscarmellose sodium was used as superdisintigrant along with blend of sodium bicarbonate, anhydrous citric acid and tartaric acid in different ratios as effervescent material and directly compressible mannitol to enhance mouth feel. The prepared batches of tablets were evaluated for weight variation, hardness, friability, drug content uniformity, in-vitro dispersion time. The tablet formulation containing 10% w/w of Crospovidone, 20% w/w sodium bicarbonate, 15%w/w citric acid and 20%w/w of MCC emerged as the overall best formulation (with an in vitro dispersion time of approximately 13s, t50% = 1.24 min and t70% = 1.65 min), based on the in-vitro drug release characteristics, compared to commercial conventional tablet formulation (which shows 118s, 13.75 min and 22.25 min respectively). Infrared spectroscopic studies revealed no drug–excipient interactions. Short-term stability studies conducted at 40 ±2°C/75±5%RH on the best formulation indicated that there were no significant changes in drug content and in-vitro dispersion time (p<0.05). The present study clearly demonstrates that fast dissolving tablets of Rosiglitazone could be successfully prepared by direct compression method in a cost effective manner....
Transdermal administration of drugs is generally limited by the barrier function of the skin. Vesicular systems are one of the most controversial methods for transdermal delivery of active substances. The interest in designing transdermal delivery systems was relaunched after the discovery of elastic vesicles: transferosomes and ethosomes. This paper presents the composition, manufacturing and characterization methods, mechanisms of penetration of transferosomes and ethosomes as transdermal delivery systems of active substances....
The main objective of the present work was to develop sustained release matrix tablets of Indomethacin using different polymers viz. Hydroxy propyl methyl cellulose (HPMC) and natural gums like Karaya gum (KG) ,Carrageenan (CG) and tamarind gum. No interaction between drug and polymer was confirmed by FTIR, which shows the suitability of all excipients with the drug to formulate the sustained release matrix tablets. Four batches of sustained release matrix tablets of with karaya gum,carrangeenan gum , tamarind gum and HPMC K 15M were prepared by using different drug: polymer ratio i.e. 1; 2, 1:2.5, 1:3 and 1:3.5 by wet granulation method. The tablets were analyzed for their various parameters such as hardness, friability, weight variation. In- vitro release was performed with the phosphate buffer of pH 7.4 for 24 hrs. Swelling index study was carried out to study the dispersibility of gums at different concentrations. The results of in vitro drug release shows that as the concentration of gum increases, swelling index also increases proportionately. Batchs F14, F15 & F16 shows maximum drug release with sustained release rate. It is clear through the dissolution study and the kinetic release study of the Indomethacin matrix tablets prepared using tamarind gum, retarded up to 24 hrs and tamarind gum is best suitable for sustained release formulation by wet granulation method....
Eye is most unique organ of the body. In the development of ophthalmic products, drug delivery is one of the most challenging and difficult fields for investigators. The usual ophthalmic dosage forms are account for 90% of currently accessible ophthalmic formulations. Various drug delivery systems are used to deliver drug into eyes are used but there are various limitations of conventional systems so researchers are finding new ways by which contact time, bioavailability and residence time can be enhanced as well as patient discomfort and frequency of dose can be reduced To improve ophthalmic drug bioavailability, there are considerable efforts directed towards newer drug delivery systems for ophthalmic administration. Newer research in ophthalmic drug delivery systems is directed towards a amalgamation of several drug delivery technologies, that includes to build up systems which is not only extend the contact time of the vehicle at the ocular surface, but which at the same time slow down the removal of the drug. The conventional formulations such as solutions, suspensions, ointments, etc. shows some constraints such as increased precorneal elimination, high variability in efficiency and blurred vision, respectively, which reduce their bioavailability. In situ activated gel forming systems are liquid upon instillation and undergo phase transition in the ocular cul-de-sac to form a viscoelastic gel in response to environmental changes such as change in temperature, pH, ion concentration and osmolarity. In the past few years, an impressive number of novel temperature, pH, and ion induced in situ gel-forming systems have been reported for sustain ophthalmic drug delivery....
Rofecoxib Transdermal patches were prepared by using different polymers such as hydroxylpropylmethylcellulose (HPMC), methylcellulose (MC), Polyvinylpyrolidone (PVP).The in-vitro release of the drug from the formulations were studied using commercial semi permeable membrane. The prepared formulation were subjected to various physicochemical evaluation test, in-vitro dissolution studies, kinetics studies shows diffusion might be one of the prominent mechanism influencing the drug release. To confirm the fact Peppa’s plot was drawn, which confirmed that the diffusion mechanism involved in the drug release was of non fickian diffusion type. ex-vivo diffusion studies by using rat skin, guinea pig skin & pig ear skin and finally in-vivo evaluation studies (the patch F4 HPMC 0.75%, PVP 0.25%) were carried out by using rabbits....
The purpose of this review on floating drug delivery systems (FDDS) is to compile the recent literature with special focus on the principal mechanism of floatation to achieve gastric retention. One of the most feasible approaches for achieving a prolonged and predictable dug delivery profiles in the gastrointestinal tract is to control the gastric residence time (GRT), using gastro retentive dosage forms that will provide us with new and important therapeutic options. From the formulation and technological point of view, the floating drug delivery system is considerably easy and logical approach. This dosage forms will be very much useful to deliver ‘narrow absorption window’ drugs. The developments of FDDS are including the physiological and formulation variables affecting gastric retention, approaches to design single-unit and multiple-unit floating systems, advantages, formulation variables and their classification are covered in detail. This review also summarizes the in vitro techniques, to evaluate the performance of floating systems....
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