A nanocrystal technology: to enhance solubility of poorly water soluble drugs

Most of the recently developed new chemical entities are poorly water soluble and they create major problems during formulation and development of new dosage form and due to poor solubility and poor bioavailability. The drugs belong to BCS class II and class IV has problem of solubility, to overcome the solubility problem nanotechnology is most useful technique. In this review article the main focus on Nanocrystals and various techniques used for preparation of Nanocrystals. Drug nanocrystals consists pure poorly water soluble drugs without any matrix material which means that it is carrier free drug delivery. Nanocrystals technologies have been introduced as advantageous, universal formulation approaches for the BCS class II and IV drugs. Nanocrystals, with greater surface to volume ratio, can effectively increase both the dissolution rate and saturation solubility of active ingredients The Nanocrystals is suitable drug delivery system for all commonly used routes of administration such as oral, IV, SC, and IM and topical application. Nanocrystals can also be incorporated into the tablets, capsules, fast-melts and lyophilized for sterile product applications. There are no of techniques which are used for production including precipitation, milling, high pressure homogenization and combination methods such as Nano-Edge, SmartCrystal and Precipitation-lyophilization-homogenization (PLH) technology

Ectopic Prostatic and Seminal Vesicle Tissue Confusing as Metastatic Adenocarcinoma

Ectopic prostatic tissue and seminal vesicle at pericolic fat is extremely rare. The nodules in the pericolic fat could raise a dilemma of metastatic deposits in cases of rectal adenocarcinoma. A 61 years old male underwent abdomino-perineal resection for rectal carcinoma. Nodules along with lymph nodes from pericolic fat were sampled to assess the spread. Histopathological and immunohistochemical staining of one nodule confirmed it to be the prostatic tissue while another nodule to be seminal vesicle. Seminal vesicle and prostatic heterotopia is significant in several respects, either symptomatic or asymptomatic, as the ectopic tissue can be endoscopically and histologically confused with malignancy of urinary or lower gastrointestinal system and may reflect divergent differentiation or a malformative process

Nonlinearities in Conservative Growth Equations

Using the dynamic renormalization group (DRG) technique, we analyze general nonlinearities in a conservative nonlinear growth equation with non-conserved gaussian white noise. We show that they fall in two classes only: the Edwards-Wilkinson and Lai-Das Sarma types, by explicitly computing the associated amputated two and three point functions at the first order in perturbation parameter(s). We further generalize this analysis to higher order nonlinearities and also suggest a physically meaningful geometric interpretation of the same.Comment: REVTEX, will appear in Phys Rev E Rapid Comm. February 1996, .ps figure file available upon request to [email protected]

Role of Doppler indices in prediction of perinatal outcome in preeclampsia

Background: Preeclampsia is a major cause of maternal and perinatal mortality and morbidity worldwide, particularly in developing countries. The objective of the study was to study Doppler indices in pregnancies with preeclampsia and to correlate Doppler indices with perinatal outcome.Methods: This was a prospective study conducted within a period of September 2012 to August 2014 where 100 singleton preeclampsia patients attending tertiary care hospital were recruited. These patients were followed by serial Doppler assessment and the result of the last Doppler examination within 10 days of delivery was considered in the subsequent correlation with perinatal outcomes. Perinatal outcome was studied under major and minor adverse outcome.Results: In this study out of total population 54% were primigravida patients. 43.75% caesarean sections done for fetal distress with abnormal Doppler. Bilateral uterine artery diastolic notch and umbilical artery S/D ratio have better sensitivity (72.55%) for prediction of minor adverse outcome while uterine artery diastolic notch has better sensitivity (86.67%) for major adverse outcome. Umbilical artery and middle cerebral artery RI have better specificity and positive predictive value  for prediction of both major and minor adverse outcome. Bilateral uterine artery notch and umbilical artery S/D ratio have better negative predictive value for prediction of both major and minor adverse outcome.Conclusions: In this study it is concluded that Doppler analysis helps not only earlier detection of uteroplacental and fetoplacental changes associated with the disease but also help to take decision for early intervention. Doppler technology has provided the best opportunity for repetitive non-invasive haemodynamic monitoring in pregnancy for fetal well-being evaluation and predicting perinatal outcome

Prediction of bead geometry using a two-stage SVM–ANN algorithm for automated tungsten inert gas (TIG) welds

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). Prediction of weld bead geometry is critical for any welding process, since several mechanical properties of the weldment depend on this. Researchers have used artificial neural networks (ANNs) to predict the bead geometry based on the input parameters for a welding process; however, the number of hidden layers used in these ANNs are limited to one due to the small amount of data usually available through experiments. This results in a reduction in the accuracy of prediction. Such ANNs are also incapable of capturing sudden changes in the input–output trends; for example, where a wide range of heat inputs results in flat crown (zero crown height), but any further reduction in the current sharply increases the crown height. In this study, it was found that above mentioned issues can be resolved on using a two-stage algorithm consisting of support vector machine (SVM) and an ANN. The two-stage SVM–ANN algorithm significantly improved the accuracy of prediction and could be used as a replacement for the multiple hidden layer ANN, without requiring additional data for training. The improvement in prediction was evident near regions of sudden changes in the input–output correlation and can lead to a better prediction of mechanical properties

Effect of the addition of nitrogen through shielding gas on tig welds made homogenously and heterogeneously on 300 series austenitic stainless steels

Copyright: © 2021 by the authors. Tungsten inert gas (TIG) welding of austenitic stainless steels is a critical process used in industries. Several properties of the welds must be controlled depending on the application. These properties, which include the geometrical, mechanical and microstructural features, can be modified through an appropriate composition of shielding gas. Researchers have studied the effects of the addition of nitrogen through the shielding gas; however, due to limited amount of experimental data, many of the interaction effects are not yet reported. In this study, welds were made homogeneously as well as heterogeneously with various concentrations of nitrogen added through the shielding gas. The gas compositions used were 99.99%Ar (pure), 2.5% N2 + Ar, 5% N2 + Ar and 10% N2 + Ar. Additionally, the welding process parameters were varied to understand different interaction effects between the shielding gas chemistry and the process variables such as filler wire feed rate, welding current, etc. Strong interactions were observed in the case of heterogeneous welds between the gas composition and the filler wire feed rate, with the penetration depth increasing by nearly 30% with the addition of 10% nitrogen in the shielding gas. The interactions were found to influence the bead geometry, which, in turn, had an effect on the mechanical properties as well as the fatigue life of the welds. A nearly 15% increase in the tensile strength of the samples was observed when using 10% nitrogen in the shielding gas, which also translated to a similar increase in the fatigue life

Ab initio calculations of structural and electronic properties of CdTe clusters

We present results of a study of small stoichiometric $Cd_{n}Te_{n}$ ($1{\leq}n{\leq}6$) clusters and few medium sized non-stoichiometric $Cd_{m}Te_{n}$ [($m,n= 13, 16, 19$); ($m{\neq}n$)] clusters using the Density Functional formalism and projector augmented wave method within the generalized gradient approximation. Structural properties {\it viz.} geometry, bond length, symmetry and electronic properties like HOMO-LUMO gap, binding energy, ionization potential and nature of bonding {\it etc.} have been analyzed. Medium sized non-stoichiometric clusters were considered as fragments of the bulk with T{$_{d}$} symmetry. It was observed that upon relaxation, the symmetry changes for the Cd rich clusters whereas the Te rich clusters retain their symmetry. The Cd rich clusters develop a HOMO-LUMO gap due to relaxation whereas there is no change in the HOMO-LUMO gap of the Te rich clusters. Thus, the symmetry of a cluster seems to be an important factor in determining the HOMO-LUMO gap.Comment: 8 pages 16 figure

Universality class of the restricted solid-on-solid model with hopping

We study the restricted solid-on-solid (RSOS) model with finite hopping distance $l_{0}$, using both analytical and numerical methods. Analytically, we use the hard-core bosonic field theory developed by the authors [Phys. Rev. E {\bf 62}, 7642 (2000)] and derive the Villain-Lai-Das Sarma (VLD) equation for the $l_{0}=\infty$ case which corresponds to the conserved RSOS (CRSOS) model and the Kardar-Parisi-Zhang (KPZ) equation for all finite values of $l_{0}$. Consequently, we find that the CRSOS model belongs to the VLD universality class and the RSOS models with any finite hopping distance belong to the KPZ universality class. There is no phase transition at a certain finite hopping distance contrary to the previous result. We confirm the analytic results using the Monte Carlo simulations for several values of the finite hopping distance.Comment: 13 pages, 3 figure

Gastroretentive drug delivery system of captopril and hydrochlorothiazide bilayer tablet: formulation, optimization and in vivo evaluation

The purpose of the present study was to develop and optimize floating-bioadhesive bilayer gastroretentive drug delivery system (GRDDS) exhibiting a unique combination of floatation and bioadhesion to prolong residence in the stomach using captopril (CP) and hydrochlorothiazide (HCTZ) as a model drug. Captopril being unstable in intestinal pH and HCTZ has specific absorption from duodenum and the first part of the jejunum and to a small extent in the stomach are suitable candidate for GRDDS. 32 factorial design was employed in formulating and optimizing the GRDDS for bilayer tablet of CP and HCTZ matrix tablet. The main effect and interaction terms were quantitatively evaluated using a mathematical model. The gastroretentive ability of the tablets was evaluated by X-radiographic studies in healthy human volunteer. The tablet releases CP and HCTZ for extended period up to 24 h in controlled manner. The predicted values agreed well with the experimental values and the results demonstrate the feasibility of the optimization methodology in the development of GRDDS. The tablet was buoyant for up to 16 h in human stomach. Development of once a day gastroretentive formulation of CP and HCTZ improves the patience compliance and bioavailability of drugs.Colegio de Farmacéuticos de la Provincia de Buenos Aire