How Good Is Local Search for Capacitated Facility Location Problem: An Experimental Study

Facility location problems have been widely studied since 1960’s. These problems are known to be strongly NP-hard. In capacitated variant of the problem, a capacity constraint is associated with each facility. Capacitated facility location problem (CFLP) instances can be solved exactly using existing MILP solvers but only for small instance sizes. As the size of the problem instance increases beyond few hundred facilities and few hundred clients, it becomes prohibitive to solve these instances exactly. For large problem instances, therefore, other solution methods are used. One approach is to use heuristic methods. These methods usually give good solutions in reasonable time but they do not provide any guarantee about the quality of the solution. Somewhere between these two extremes exist another class of algorithms called approximation algorithms. They also provide only suboptimal solutions to the problem, like heuristic algorithms, in polynomial time. How ever they guarantee worst case upper bounds on the cost of the solution. So, a solution obtained using an approximation algorithm is guaranteed to have its cost between the optimal cost and the upper bound. We present experimental studies done with a local search based approximation algorithm for CFLP given by Bansal et al. [1] to show that this algorithm performs well in practice

BiETech : Bicluster Ensemble Techniques

Various biclustering algorithms have emerged now a days that try to deliver good biclusters from gene expression data which satisfy a particular objective function. Users are lost in finding the best out of these algorithms. Ensemble techniques come to rescue     of these users by aggregating all the solutions and providing a single solution which is more robust and stable than its constituent solutions.  In this paper, we present two different ensemble techniques for biclustering solutions. We have used classifiers in one approach and the other approach uses the concept of metaclustering for forming the consensus. Experiments in this research are performed   on synthetic and real gene expression datasets as biologists are interested in finding meaningful patterns in expression of genes.  The experiments show that both the approaches proposed in the paper show improvement over the input solutions as well as the existing bicluster ensemble techniques

Microneedle Mediated Vaccine Delivery: A Comprehensive Review

Microneedles can be representative for paradigm shift of drug delivery from patient non-compliant parenteral injections to patient compliant drug delivery system, which can be utilized for administration of vaccines particularly along with macromolecular/micromolecular drugs. The concept of microneedles came into existence many decades ago but the use of microneedles to achieve efficient delivery of drugs into the skin became subject of research from mid of 1990’s. Various types of microneedles were utilized to enhance delivery of drugs and vaccines including solid microneedles for pre-treatment of skin to enhance drug permeability, dissolvable polymeric microneedles encapsulating drugs, microneedles coated with drugs and hollow microneedles for infusion of drugs through the skin. Microneedles have shown promisingdelivery of vaccines through skin in literature. But the successful utilization of this system for vaccine drug delivery mainly depends on design of device to facilitate microneedle infusion, vaccine stability and storage in system, recovery of skin on removal of microneedle and improved patient compliance. This article reviews the conventional and advanced methods of vaccine drug deliver, microneedles for drug delivery, types of microneedles, advantages of microneedles and potential of microneedles for vaccine drug delivery

Formulation and development of colon-targeted mucopenetrating metronidazole nanoparticles

Purpose: To formulation and develop colon-targeted mucopenetrating metronidazole nanoparticles.Methods: Metronidazole-loaded chitosan nanoparticles with a pH-sensitive polymer, hydroxyl propyl methyl cellulose phthalate (HPMCP), were prepared by ionic gelation technique and then coated with Eudragit S100 by solvent evaporation method. The nanoparticles were optimized using one variable at a time (OVAT) approach. Further, the nanoparticles were evaluated by scanning electron microscopy (SEM) and zeta sizer, as well as for in-vitro release. Muco-adhesion was evaluated by modified bioadhesion detachment force measurement balance and muco-penetration of fluorescein isothiocyanate (FITC) labeled optimized nanoparticles was determined by microscopic techniqueResults: Morphological assessment results revealed smooth, spherical particles with homogeneous distribution and polydispersity index (PDI) of 0.213. The optimized formulation showed particle size of 202 ± 27 nm, zeta potential of 26.9 ± 2.4 mV as well as and entrapment efficiency of 79 ± 5.4 %. There was significant difference in drug release between coated (8.46 ± 2.49 %) and uncoated (28.96 ± 4.04%) nanoparticles at the 5th h in simulated gastric conditions. Muco-adhesion data revealed that uncoated nanoparticles (14.98 x 103 dyne/cm2) showed higher muco-adhesion detachment force compared to coated (12.34 x 103 dyne/cm2) nanoparticles. Muco-penetration results confirm the retention (for up to 12 h) of the developed formulation at the target site for enhanced therapeutic exposure of the entrapped drug.Conclusion: Eudragit S100 coating of chitosan-HPMCP nanoparticles promotes efficient drug targeting and thus provides a strategy for treating mucosal infections. .Keywords: Metronidazole, pH-sensitive nanoparticles, Hydroxylpropyl methylcellulose phthalate, Ionic gelation, Mucoadhesion, Mucopenetration, Intestinal infectio

Diabetes mellitus treatment using herbal drugs

Diabetes mellitus is becoming a common metabolic disorder which has serious threat to public health in the world. There are chemicals and biochemical agent that helps in controlling diabetes but there is no permanent remedy available which helps to get recovered completely from this disorder. By conducting large number of research work, numerous traditional medicines have been found for diabetes. Substances and extracts isolated from different natural resources especially plants have always been a rich arsenal for controlling and treating diabetes problem and complication arising due to it. So this review helps the reader to understand the importance of various types of herbal and polyherbal formulations present traditionally which can be used to treat diabetes mellitus.

BIOAVAILABILITY ENHANCDEMENT OF POORLY SOLUBLE DRUGS BY SMEDDS: A REVIEW

Oral route has always been the favorite route of drug administration in many diseases and till today it is the first way investigated in the development of new dosage forms. The major problem in oral drug formulations is low and erratic bioavailability, which mainly results from poor aqueous solubility, thereby pretense problems in their formulation. More than 40% of potential drug products suffer from poor water solubility. For the therapeutic delivery of lipophilic active moieties (BCS class II drugs), lipid based formulations are inviting increasing attention. Currently a number of technologies are available to deal with the poor solubility, dissolution rate and bioavailability of insoluble drugs such as micronization, solid dispersions or cyclodextrin complex formation and different technologies of drug delivery systems. One of the promising techniques is Selfâ€Micro Emulsifying Drug Delivery Systems (SMEDDS). Self emulsifying drug delivery system has gained more attention due to enhanced oral bio-availability enabling reduction in dose, more consistent temporal profiles of drug absorption, selective targeting of drug(s) toward specific absorption window in GIT, and protection of drug(s) from the unreceptive environment in gut. This article gives a complete overview of SMEDDS as a promising approach to effectively deal with the problem of poorly soluble molecules. Keywords: SMEDDS, surfactant, oil, co-surfactant, bioavailabilit

EXTRACTION OF GUM FROM ABELMOSCHUS ESCULENTUS: PHYSICOCHEMICAL PECULIARITY AND ANTIOXIDANT PREPATENT

  Objective: This study is aimed to extract gum from Abelmoschus esculentus using ultrasonic assisted method and exploring physicochemical, functional, and antioxidant potential of gum for food and pharmaceuticals.Materials and Methods: The extraction of gum from okra was done employing ultrasound-assisted method to improvise the yield. The extracted gum was further characterized for physical properties including swelling index, solubility, water sorption time, packing and flow properties, electrical properties, zeta potential, scanning electron microscopy, and antioxidant activity.Results: The extraction yield of okra fruit gum (OFG) was found to be 31.52%±0.22% (n=3). The OFG powder obtained after lyophilization showed good flow properties as determined from the results of angle of repose (34.21°), Hausner ratio (1.14), and % compressibility (12.5%). An increase in solubility and swelling index of OFG with increase in pH of buffer from 2.0 to 7.4 was observed. The freeze dried OFG possess rough surface and zeta potential of −9.85 mV. Application of derivatized/interacted OFG gum for modification of drug release profiles is concluded from high degree of esterification of 7.8.Conclusion: The result suggest that the antioxidant activity of OFG was higher compared to corn flour gum. Thus, OFG could be utilized as natural antioxidant food ingredients and also for application in medicine and health-care products

Development and characterization of an atorvastatin solid dispersion formulation using skimmed milk for improved oral bioavailability

AbstractAtorvastatin has low aqueous solubility resulting in low oral bioavailability (12%) and thus presents a challenge in formulating a suitable dosage form. To improve the aqueous solubility, a solid dispersion formulation of atorvastatin was prepared by lyophilization utilising skimmed milk as a carrier. Six different formulations were prepared with varying ratios of drug and carrier and the corresponding physical mixtures were also prepared. The formation of a solid dispersion formulation was confirmed by differential scanning calorimetry and X-ray diffraction studies. The optimum drug-to-carrier ratio of 1:9 enhanced solubility nearly 33-fold as compared to pure drug. In vitro drug release studies exhibited a cumulative release of 83.69% as compared to 22.7% for the pure drug. Additionally, scanning electron microscopy studies suggested the conversion of crystalline atorvastatin to an amorphous form. In a Triton-induced hyperlipidemia model, a 3-fold increase in the lipid lowering potential was obtained with the reformulated drug as compared to pure drug. These results suggest that solid dispersion of atorvastatin using skimmed milk as carrier is a promising approach for oral delivery of atorvastatin

Early Postoperative Death in Patients Undergoing Emergency High-Risk Surgery:Towards a Better Understanding of Patients for Whom Surgery May Not Be Beneficial

The timing, causes, and quality of care for patients who die after emergency laparotomy have not been extensively reported. A large database of 13,953 patients undergoing emergency laparotomy, between July 2014 and March 2017, from 28 hospitals in England was studied. Anonymized data was extracted on day of death, patient demographics, operative details, compliance with standards of care, and 30-day and in-patient mortality. Thirty-day mortality was 8.9%, and overall inpatient mortality was 9.8%. Almost 40% of postoperative deaths occurred within three days of surgery, and 70% of these early deaths occurred on the day of surgery or the first postoperative day. Such early deaths could be considered nonbeneficial surgery. Patients who died within three days of surgery had a significantly higher preoperative lactate, American Society of Anesthesiologists Physical Status (ASA-PS) grade, and Physiological and Operative Severity Score for the enumeration of Mortality and morbidity (P-POSSUM). Compliance with perioperative standards of care based on the Emergency Laparotomy Collaborative care bundle was high overall and better for those patients who died within three days of surgery. Multidisciplinary team involvement from intensive care, care of the elderly physicians, and palliative care may help both the communication and the burden of responsibility in deciding on the risk–benefit of operative versus nonoperative approaches to care