Percentage Buoyancy Research Articles

Development and Evaluation of Eplerenone Microbeads as Floating Drug Delivery System using Design of Experiment

The present study was designed to formulate floating microbeads of eplerenone for decreasing dosing frequency and increasing gastric residence. The floating properties of the gastric juice were used to control the stomach stay time. Eplerenone was selected as a model bioactive which is used in lowering blood pressure by loading into floating microspheres was designed by using polymer ethyl cellulose and solvent ratio (Dichloromethane: methanol), keeping. The floating microbeads were studied for their drug entrapment efficiency, shape, percentage yield, and particle size, surface morphology, in-vitro drug release studies, percentage buoyancy, and formulation stability studies. Dichloromethane we used (DCM) as a constant and stirred them for hours. The study showed that fluid evaporation can be used to make floating microbeads that contain eplerenone. This method can be used to successfully make eplerenone-loaded floating microbeads. The study showed that making floating eplerenone microbeads with controlled release is a good way to cut down on how often you have to take your medicine.

Development and evaluation of ketoprofen loaded floating microspheres for sustained delivery

Present study was designed with the objective of formulating floating microspheres of ketoprofen for sustaining the drug release. Ketoprofen is a cyclooxygenase inhibitor widely employed for treating arthritis. It has a bitter taste and off taste and also irritates the gastric mucosa. Its half-life is only 1–2 hrs. Floating microspheres of ketoprofen would help prevent gastric irritation, mask the taste of the drug and decrease the dosing frequency. Formulation and optimization of microsphere was done by employing sodium alginate and chitosan as the polymer by application of ionotropic gelation method and assessed for various properties. The outcome of optimization shows a smooth surface and narrow size distribution. The DSC and FTIR analysis indicated that the polymer was not incompatible with the drug. After 8 h, 92.74 % of the medicament was released in vitro. Based on the findings of this study, Chitosan and Sodium alginate -loaded microspheres of ketoprofen may be fruitfully used to develop floating sustained delivery systems. The formulation, MF7 was found to be a promising formulation, based on its percentage yield, percentage buoyancy, and floating lag time and other evaluated parameters. The prepared floating microspheres are suitable for sustained drug delivery of ketoprofen, and adapted well for different intragastric conditions. The ionic gelation method proved to be a suitable method for fabricating ketoprofen microspheres for sustained drug delivery, thereby achieving the objective of the study.

Development and Characterization of Repaglinide Loaded Floating Microparticles

Sustained release drug delivery has been successfully achieved using microparticles made from natural or synthetic polymers. The aim of this study is to develop and test floating microparticles of Repaglinide in order to improve drug bioavailability by extending gastric residence time. Repaglinide, an oral hypoglycemic, is a lipophilic drug that is rapidly absorbed from the stomach and eliminated with a half-life of just 1 h, so suitable to be formulated as floating drug delivery system for sustained release.Repaglinide floating microparticles were developed using an ionotropic gelation method that included calcium chloride as a cross-linking agent, sodium alginate, and different concentrations of hydroxypropyl methylcellulose (HPMC), ethyl cellulose (EC), and sodium bicarbonate (NaHCO3). A three factor, three-level Box-Behnken design was used to study the effect of independent variables on dependent variables. In the formulation of microparticles, the amount of hydroxypropyl methylcellulose (X1), ethyl cellulose (X2), and sodium bicarbonate (X3) were three independent variables, while percentage buoyancy (Y1) and percentage drug release at 10 h (Y2) were dependent variables. Micromeritic properties, percent yield, percent drug entrapment performance, surface morphology, percent buoyancy, in-vitro drug release, and drug excipient compatibility were all assessed in the formulations.FTIR studies revealed no interaction between the drug and the excipients.SEM for surface morphology studies revealed that their surface is spherical and smooth. The mean particle size of formulations was found to be between 415- 689 µm, the drug entrapment efficiency was found to be between 44.65% - 76.55% and percent buoyancy was noted to be between 63%- 78.33%. The results revealed that entrapment efficiency increased as polymer concentration was increased. The cumulative percent drug release after 10 h was noted to be between 76.87- 88.12%. Percent drug release decreased as polymers concentration was increased. The buoyancy was increased with increasing concentration of sodium bicarbonate. The developed microparticles could successfully retard the release of the drug.

The buoyancy-based biotope axis of the evolutionary radiation of Antarctic cryonotothenioid fishes

In the absence of any prior comprehensive analysis, I evaluate divergence along the biotope axis in the habitat stage of the evolutionary radiation of Antarctic cryonotothenioids. I utilize the available percentage buoyancy (%B) measurements as habitat proxies for recognition of the pelagic, semipelagic, demersal, and benthic biotopes that include, respectively, 5%, 10%, 73%, and 12% of the 59 species and 1749 specimens in the study. The majority of species retain the ancestral demersal biotope of Eleginops maclovinus, and this probably enhances ecological plasticity. Divergence into the pelagic biotope is the most distinctive organismal feature of the radiation and, although only 5% of species are pelagic, this biotope is not depauperate in global comparisons. Pelagic or potentially pelagic species are Dissostichus mawsoni, D. eleginoides, Pleuragramma antarctica, Aethotaxis mitopteryx, and Gvozdarus svetovidovi. Small ontogenetic changes in %B with growth are typical; however, this is extensive in D. mawsoni, a species with the potential to transition through benthic to pelagic biotopes over ontogeny. Occupation of the pelagic biotope by large D. mawsoni may be impermanent as it is lipid-dependent, a contingency reliant on the availability of P. antarctica as prey. In unusual conditions, the specialized sacs of P. antarctica can also yield their lipid for metabolism with possible loss of buoyancy. Pelagic species are inordinately important in the food web. In the southwestern Ross Sea a guild of large mammalian and avian predators, which includes D. mawsoni, is reliant on lipid-rich, energy-dense cryonotothenioid prey. This includes asymmetrical intraguild predation on D. mawsoni, with P. antarctica as a basal resource for the guild.

Development, optimization and In vitro evaluation of sintered floating tablets of Antibacterial drug

Floating tablets prolongs drug residence , enhance bioavailability and facilitate effective eradication of helicobacter pylori includes local delivery of antibiotic in stomach. The goal of the existing research changed into to formulate thermally sintered floating Tablets of Amoxicillin Trihydrate, and to test sintering effect on release of drug and floating. A hydrophobic polymer, Carnauba wax, is determined to delay the release of drug as a sintered polymer. Formulations had been organized via granulation technique and had been evaluated through in vitro research such as hardness, friability, uniformity of weight, percentage drug content, buoyancy time, dissolution and release mechanism. Optimization was based on buoyancy time and in vitro release. Hardness ranged from 4-6 kg/cm2. Friability, drug content and weight variation passed USP requirements. Buoyancy time of all tablets was below 3 min and tablet remained floating throughout the study. Effects showed that temperature to sinter and exposure time significantly motivated buoyancy, in addition to dissolution characteristics. Sintering improved floating properties, general time of floating was extended and retarded release of medicament . Robust sintered components (sintering temperature 50°C and time of exposure 4 h became selected, primarily based on retarding character. The formulations characterised with FTIR studies and no interplay become determined between the drug and the polymer.

Formulation and Evaluation of Floating Microspheres of 1,1-Dimethylbiguanide

1,1-Dimethylbiguanide is a hypoglycemic agent used in the treatment of non-insulin dependent Diabetes mellitus. It is a BCS Class –III drug having poor permeability. Plasma half life ranges from 1.5-3 hrs & oral bioavailability is 50-60%. Hence require frequent oral administration for adequate treatment of Diabetes in order to extend the gastric retention time oral sustained dosage form was developed in the form of microspheres using polymers (sodium CMC, HPMC K 100 M). The results presented that drug dissolution rate and drug entrapment increases while decreasing the polymer amount. All the formulations are evaluated for dissolution, entrapment efficiency, percentage buoyancy and 1,1-Dimethylbiguanide Microspheres of formulations, F-4 was found to be optimized formulation based on in-vitro release pattern and percentage buoyancy entrapment efficiency. Keywords: 1,1-Dimethylbiguanide, half-life formulations, efficiency.

Formulation Development and Evaluation of Floating Microsphere of Famotidine for the Treatment of Peptic Ulcer

The purpose of this research was to prepare a floating drug delivery system of famotidine. The floating microspheres can be prepared for the improvement of absorption and bioavailability of famotidine by retaining the system in the stomach for prolonged period of time. Floating microspheres of famotidine were prepared using different polymers like ethyl cellulose, hydroxy propyl methyl cellulose by solvent diffusion-evaporation method. The microspheres had smooth surfaces with free-flowing and good-packing properties. The yield of the microspheres was up to 73.32±0.14% and ethyl cellulose microspheres entrapped the maximum amount of the drug. Scanning electron microscopy confirmed their hollow structures with sizes in 331.6 nm. The prepared microspheres exhibited prolonged drug release and Percentage buoyancy was found to 73.25±0.23. The formulated batches were evaluated for percentage yield, particle size measurement, flow properties, percent entrapment efficiency, swelling studies. The formulations were subjected to stability studies and In-vitro release and release kinetics data was subjected to different dissolution models. It was concluded that developed floating microspheres of famotidine offers a suitable and practical approach for prolonged release of drug over an extended period of time and thus oral bioavailability, efficacy and patient compliance is improved.
 Keywords: Famotidine, Solvent diffusion evaporation method, Ethyl cellulose, Hydroxyl propyl methyl cellulose

FORMULATION, CHARACTERIZATION AND IN VITRO EVALUATION OF FLOATING MICROSPHERES OF MEBENDAZOLE AS A GASTRO RETENTIVE DOSAGE FORM

The present study involves preparation and evaluation of floating microspheres using Mebendazole (MBZ) as a model drug for improving the drug bioavailability by prolongation of gastric retention time. Ethyl cellulose, hydroxyl propyl methyl cellulose microspheres loaded with mebendazole were prepared by solvent diffusion evaporation method. The microspheres had smooth surfaces, with free-flowing and good-packing properties. The yield of the microspheres was up to 85.65±0.14% and ethyl cellulose microspheres entrapped the maximum amount of the drug. Scanning electron microscopy confirmed their hollow structures with sizes in the range 215.1 to 251.80 nm. The prepared microspheres exhibited prolonged drug release and Percentage buoyancy was found to70.25±0.15. The formulated batches were evaluated for percentage yield, particle size measurement, flow properties, percent entrapment efficiency, swelling studies. The formulations were subjected to Stability studies and In-vitro release and Release kinetics data was subjected to different dissolution models.
 Keywords: solvent diffusion evaporation method, Mebendazole, Ethyl cellulose, Hydroxyl propyl methyl cellulose

Preparation and Evaluation of Isoniazid Microbeads by using Different Membrane

Current experimental investigation is dedicated to formulated alginate floating microbeads of Isoniazid as a model drug by ion cross-linking method or ion gelation technique using calcium chloride as cross-linking agent. Drug effectiveness might be influenced by blood plasma protein binding. The less bound drug is more viable it can cross cell membrane and diffuse. Protein binding can impact the drug’s biological half-life in the body. Isoniazid was first generation antibiotic which are used for the resistance is an obstacle to the treatment of tuberculosis disease and latent tuberculosis infection. The permeability of Isoniazid study using different membrane (Egg membrane and cellophane membrane). The IN VITRO drug release studies showed the optimized formulation of drug release 91 % in cellophane membrane and 88 % in egg membrane at 60 mins. The percentage buoyancy and swelling index of microbeads F1-F4 respectively 53-72% and 56-76%. The drug entrapment efficiency of the microbeads prepared from sodium alginate alone were found to be in the range of 52-71%.Experimental report revealed that Isoniazid loaded microbeads may act as ideal nano formulation with elaborated studies.

Development and Evaluation of Olmesartan Medoxomil Controlled Release Floating Microspheres using Natural Gums

The present research was aimed to prepare Olmesartan medoxomil floating microspheres for controlled release using polymers such as sodium alginate, sodium bicarbonate, calcium chloride, Hydroxy propyl methyl cellulose (HPMC K4M, K15M), Olibanum gum and Xanthan gum by ionotropic gelation method. The prepared microspheres were evaluated for the percent drug content, entrapment efficiency, percentage buoyancy and in vitro dissolution studies. Among all the formulations F14 was selected as optimized formulation based on the micromeretic and physico-chemical parameters including drug release studies. Percentage buoyancy of optimized formulation was found to be 96.45%. In vitro release study of formulation F14 showed 98.11% drug release after 12 h in a controlled manner, which is desired for disease like Hypertension. The reference standard shows the drug release of 94.12% within 12 h. Drug and excipient compatibility studies were carried out by FT-IR and no interactions were observed. The SEM of microspheres show a hollow spherical structure with a rough surface morphology. Some of microspheres showed dented surface structure but they showed good floating ability on medium indicated intact surface. The shell of microspheres also showed some porous structure which might be due to release of carbon dioxide. F14 followed zero order, Higuchi and Korsmeyer Peppas kinetics indicating diffusion controlled with non-fickian (anomalous) transport, projecting that its active ingredient are delivered by coupled diffusion and erosion. From these results, it can be concluded that the polymer proportion controlled the drug release from the olmesartan floating microspheres.

FORMULATION AND IN-VITRO EVALUATION OF FLOATING MICROBALLOONS OF STAVUDINE

Objectives: Objective of present study involves preparation and evaluation of floating microballoons of Stavudine. It is a potent antiviral agent, used for treatment of human immunodeficiency virus (HIV) infection. In present study Stavudine is used as a model drug, to increase its residence time in the stomach without contact with the mucosa. Methods: Eight floating microballoons formulations of Stavudine were prepared by using different polymers i.e. Eudragit S100, EC and PVP K30, in different ratio by emulsion solvent diffusion method. The microballoons were prepared by the emulsion solvent diffusion technique using different ratio of polymers (Eudragit S100, Ethyl cellulose and PVP K 30) as carriers. Results: The mean particle diameter of the microballoons was between 230.23-238.33µm.The yield of microballoons was up to 68.32-80.22%. The cumulative percent drug release after 24 hrs of the Stavudine microballoons was in the range of 53.62 to 87.45%. The mean percentage buoyancy of the microballoons was between 69.23-82.53%. The cumulative percent drug release after 24 hrs of the Stavudine microballoons was 53.62 to 87.45%. Conclusion: Stavudine floating microballoons formulations of batch MB4 was concluded as the optimum formulations among the all 8 formulations based on different parameters.Study concludes that stavudine can be delivered through floating microballoons dosage form in an effective way. Peer Review History: Article received on- 29 September; Revised on- 20 October; Accepted on- 5 November , Available online 15 November 2016 Academic Editor: Ahmad Najib, Universitas Muslim Indonesia, Indonesia, ahmad.najib@umi.ac.id UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency. Received file: Reviewer's Comments: Average Peer review marks at initial stage: 4.5/10 Average Peer review marks at publication stage: 7.5/10 Reviewer(s) detail: Dr. Michael Otakhor Erhunmwunse, St. Philomena Catholic Hospital, Nigeria, dedoctor4life@gmail.com Prof. Dr. Kapil Kumar, Global Institute of Pharmaceutical Education and Research, Kashipur, US Nagar, Uttarakhand, India, kapil5november@gmail.com Similar Articles: DEVELOPMENT AND EVALUATION OF IN SITU GELLING GASTRORETENTIVE FORMULATIONS OF MELOXICAM FORMULATION AND EVALUATION OF IBUPROFEN GASTRO-RETENTIVE FLOATING TABLETS DEVELOPMENT AND EVALUATION OF RITONAVIR HOLLOW MICROBALLOONS FOR FLOATING DRUG DELIVERY FORMULATION AND IN-VITRO EVALUATION OF FLOATING MICROBALLOONS OF STAVUDINE

Optimization of diltiazem hydrochloride loaded mucoadhesive floating microspheres using calcium carbonate as gas generating agent as floatation aid

Abstract: Considering the advantages offered by oral prolonged release multiparticulate gastroretentive dosage forms for drugs with narrow absorption window, the objective of this study was to develop mucoadhesive floating microspheres of diltiazem hydrochloride that is anticipated to overcome poor oral drug bioavailability. A 32 full factorial design was employed for optimization wherein concentration of ethyl cellulose and carbopol 934P were chosen as independent variables. Calcium carbonate used as gas generating agent to aid floatation. Percentage buoyancy, mucoadhesion and percentage cumulative drug release for 8 h were taken as dependent variables. A total of nine formulations (F1-F9) were developed by emulsion-solvent evaporation method and evaluated. The particle size, percentage entrapment efficiency, percentage buoyancy, percentage mucoadhesion and percentage cumulative drug release of the optimized formulation (F7) was found to be 160.2±18.87µm, 55.49±1.44%, 84.83±3.89%, 90.66±3.46% and 90.38±1.34% respectively. The in vitro drug release best fitted Higuchi kinetics and the experimental design was validated by extra design check point. DRS revealed no chemical interaction between the drug and polymer used. The spherical shape of microspheres was defined using SEM. DSC and XRD confirmed molecular dispersion of the drug in the microspheres polymeric matrix. The optimized formulation was found to be stable for a period of 3 months. Key words: Diltiazem hydrochloride, mucoadhesive floating microspheres, optimization, stability.

Formulation, Optimization and Evaluation of Gastro-Retentive Floating Microspheres of Norfloxacin

The objective of the present study was to develop floating microsphere of norfloxacin in order to achieve an extended retention in the upper GIT which may enhance the absorption and improve the bioavailability. The microspheres were prepared by solvent evaporation method using different ratio of hydroxyl propyl methyl cellulose (HPMC K4M, HPMC K15M) and ethyl cellulose with drug in the mixture dichloromethane and ethanol at ratio of (1:1) with tween 80 (stabilizing agent). FTIR study shows that drug and other excipients are compatible with each other. The effects of polymer concentration on drug release profile were investigated. A 3 3 centre-composite design was applied to systemically optimize the drug release profile. Polymer to drug ratio; HPMC K4M (X 1 ), HPMC K15M (X 2 ) and stirring speed (X 3 ) were selected as independent variables. The floating microspheres were characterized by the results obtained as percentage yield, percentage buoyancy and in-vitro drug release was studied for 12 hour. The Surface morphology studied by scanning electron microscopy and Accelerated stability study was performed for three months indicated that optimized formulation was stable. The floating microspheres showed better result and it may be useful for prolong the drug release in stomach and improve the bioavailability.

Formulation and in vitro evaluation of prolonged release floating microspheres of atenolol using multicompartment dissolution apparatus

The aim of the present work was to prepare floating microspheres of atenolol as prolonged release multiparticulate system and evaluate it using novel multi-compartment dissolution apparatus. Atenolol loaded floating microspheres were prepared by emulsion solvent evaporation method using 32 full factorial design. Formulations F1 to F9 were prepared using two independent variables (polymer ratio and % polyvinyl alcohol) and evaluated for dependent variables (particle size, percentage drug entrapment efficiency and percentage buoyancy). The formulation(F8) with particle size of 329 ± 2.69 µm, percentage entrapment efficiency of 61.33% and percentage buoyancy of 96.33% for 12 h was the of optimized formulation (F8). The results of factorial design revealed that the independent variables significantly affected the particle size, percentage drug entrapment efficiency and percentage buoyancy of the microspheres. In vitro drug release study revealed zero order release from F8 (98.33% in 12 h). SEM revealed the hollow cavity and smooth surface of the hollow microspheres.

Formulation and evaluation of controlled release floating microspheres of tolperisone hydrochloride

Main aim of this study was to develop controlled release (CR) floating multiparticulate drug delivery system of tolperisone hydrochloride. Microspheres were prepared by nonaqueous solvent evaporation technique consisting of porous calcium silicate (Florite or FLR) as porous carrier, tolperisone hydrochloride (API), Ethyl cellulose (EC), and HPMC 15 cPs as rate controlling polymers. 23 full factorial design was applied for optimization of formulation. The effect of various formulation and process variables on the particle morphology, micromeritic properties, in vitro floating behavior, entrapment efficiency, and in vitro drug release were studied. The size of microspheres was varied from 300 to 500 μm. The microspheres were found to be highly porous and regular in shape. All the formulations showed excellent flow properties. The percentage entrapment efficiency of all batches was greater than 80%. The percentage buoyancy varied from 85% to 98% at the end of 12 h. The release rate was determined in simulated gastric fluids. The formulation demonstrated favorable in vitro floating and release characteristics. Different kinetic models were applied to study the release mechanism. All formulations followed Higuchi model, which indicates the diffusion control release of water soluble drug from polymer matrix. Multiple regression analysis was applied for study of the effect of independent variables on the dependent variables.

Adaptive radiation at a low taxonomic level: ­divergence in buoyancy of the ecologically similar Antarctic fish Notothenia coriiceps and N. rossii

We studied the buoyancy of 263 specimens of the sympatric sister species Notothenia coriiceps and N. rossii captured at King George Island. In these species without a swim bladder, we expressed measurements of buoyancy as percentage buoyancy (%B = weight in water/weight in air × 100), with smaller numbers reflecting more buoyant (i.e. less dense) species. Mean %B of N. coriiceps (4.34%) was significantly greater than that of N. rossii (3.82%), reflecting the lower density and more active swimming, migratory, and feeding behavior of N. rossii compared to N. coriiceps. Skeletal weight as a percentage of body weight was also significantly greater in N. cori- iceps (2.46%) than N. rossii (1.65%). Paradoxically, the weight of the vertebral column as a per- centage of skeletal weight was significantly greater in N. rossii (28.01%) than in N. coriiceps (24.29%); however, this is intelligible in light of the bone anatomy and histology. Our sample encompassed a wide size and age range, and trend lines for scatter plots of %B against standard length were curvilinear for both species, peaking at 140 to 160 mm, a phenomenon not previously seen in studies of notothenioid buoyancy. We conclude that the ontogenetic increase in %B (reduced buoyancy) in fingerlings/young juveniles and the ontogenetic decrease in %B (increased buoyancy) in older juveniles/immature adults reflects disproportionate growth of skele- tal and visceral tissues, respectively, and is not causally related to concurrent pelagic-demersal habitat shifts.

Buoyancy of sub-Antarctic notothenioids including the sister lineage of all other notothenioids (Bovichtidae)

The radiation of notothenioid fishes (Perciformes) in Antarctic waters was likely the result of an absence of competition in the isolated Antarctic waters and key traits such as the production of antifreeze glycoprotein and buoyancy modifications. Although notothenioids lack a swim bladder, the buoyancy of Antarctic species, ranging from neutrally buoyant to relatively heavy, corresponds to diverse life styles. The buoyancy of South American notothenioids has not been studied. Static buoyancy was measured in adult notothenioids (n = 263, from six species of the sub-order Notothenioidei, families Bovichtidae, Eleginopidae, Nototheniidae, and Harpagiferidae) from the Beagle Channel. Measurements were expressed as percentage buoyancy (%B). Buoyancy ranged from 3.88 to 6.96% (median, 4.0–6.7%), and therefore, all species could be considered benthic consistent with previous studies that found that neutral buoyancy in notothenioids is rare. Harpagifer bispinis, Patagonotothen cornucola, and Cottoperca gobio were significantly less buoyant than Paranotothenia magellanica. The buoyancy values of most species were concordant with known habitat preferences. These data, especially the data of C. gobio (sister lineage of all other nototehnioids) and E. maclovinus (sister lineage of the Antarctic clade of notothenioids), could be useful for understanding the diversification of this feature during the notothenioid radiation.

Development and Characterization of Rifampicin Loaded Floating Microspheres

Gastroretentive floating microspheres have a potential for enhancing the bioavailability and controlled delivery of drugs. The present study involves development of rifampicin floating microspheres in order to increase the gastric retention time. The microspheres were prepared by solvent evaporation technique and characterized for particle size, shape, zeta-potential, entrapment, and release kinetics. The developed systems were almost spherical in shape. The entrapment efficiency was found to be 86.34%. The percentage buoyancy after 8 hours was found to be 61.06. The prepared microspheres exhibited prolonged drug release in gastric medium and hence could be utilized for sustained delivery of anti-tubercular drugs.

Formulation development and in vitro evaluation of gastroretentive hollow microspheres of famotidine

Background:The main aim of this study was to develop a gastroretentive, multiple-unit floating drug delivery system for a drug which is poorly absorbed from the lower gastrointestinal tract. Such a dosage form may provide an extended retention of drug in the upper gastrointestinal tract resulting in enhanced absorption and improved bioavailability.Materials and Methods:Microspheres were prepared by the emulsion solvent diffusion method. Four different ratios (1:1, 1:2, 1:3, and 1:4) from each polymer, i.e., Eudragit RL 100 (E1–E4) and cellulose acetate (C1–C4) were prepared.Results:Hollow microspheres were characterized by particle size using optical microscopy. The in vitro release data obtained for the formulations E1–E4 and C1–C4 showed good entrapment efficiency, good percentage buoyancy, and prolonged drug release. The in vitro drug release showed the highest regression coefficient values for Higuchi's model, indicating diffusion to be the predominant mechanism of drug release. The surface and cross-sectional morphology of the formulations E1-A and C1-A were determined using scanning electron microscopy.Conclusions:Thus, prepared floating hollow microspheres of famotidine may prove to be potential candidates for the multiple-unit drug delivery device adaptable for any intragastric condition.

Biology of the Antarctic dragonfishVomeridens infuscipinnis(Notothenioidei: Bathydraconidae)

AbstractNineteen specimens of the rare dragonfishVomeridens infuscipinniswere evaluated for meristic counts, morphometric measurements, vomerine teeth and the supratemporal canal, anatomical and histological observations of bone, cartilage and lipid, diet, and reproductive status. Seven individuals were measured for buoyancy. All specimens had small vomerine teeth that varied in number. There was also variability in the arrangement of the supratemporal pores and canals.Vomeridenspossess a body with little bone and considerable amounts of cartilage and lipid. A mean percentage buoyancy of 1.61% indicated thatVomeridensis nearly neutrally buoyant. Inferences from measurements of buoyancy and from morphological data suggest thatVomeridenslives in an epibenthic water column habitat at 400–900 m. Facilitated by its reduced body density,Vomeridensare likely to forage in the water column by hovering above the substrate. The stomach contents consisted of krill (Euphausia superba), some as large as 46–50 mm.The absolute and relative fecundity in seven female was 1576–2296 oocytes (mean 1889) and 21.3–28.9 oocytes g-1body weight (mean 25.3), respectively. The reproductive effort in terms of egg diameter, GSI, and absolute and relative fecundity is similar to that for other bathydraconids.