Enhancement of Drugs Bioavailability by Floating Drug Delivery System – A Review

Gastric emptying is a complex process and one of the most important obstacles in the better absorption and enhances bioavailability of oral drug delivery system. In recent years various scientific and technological advancements have been made in the research and development of oral drug delivery systems to overcoming physiological adversities, such as short gastric residence times (GRT) and unpredictable gastric emptying time (GET). In order to avoid such adversities, efforts have been made to increase the retention time of the drug-delivery systems for more than 12 hour via floating drug delivery system. Floating delivery systems or hydro dynamically controlled systems are low density systems that have sufficient buoyancy to float over the gastric content and remain buoyant in the stomach. The recent development of these systems includes their physiological and formulation variables affecting the gastric retention and to design the single and multiple-unit floating systems and their formulation, evaluation aspects are covered in detail. This article aims at reviewing the numerous techniques that has been designed till date for optimizing floating drug delivery system (FDDS), and also summarize the evaluation of FDDS of tablet dosage forms

Atypical Neuroimaging Manifestations of Linear Scleroderma “en coup de sabre”

How to Cite This Article: Allmendinger AM, Ricci JA, Desai NS, Viswanadhan N, Rodriguez D. Atypical Neuroimaging Manifestations of Linear Scleroderma “en coup de sabre”. Iran J Child Neurol. Summer 2015;9(3):62-68.AbstractLinear scleroderma “en coup de sabre” is a subset of localized sclerodermawith band-like sclerotic lesions typically involving the fronto-parietal regionsof the scalp. Patients often present with neurologic symptoms. On imaging,patients may have lesions in the cerebrum ipsilateral to the scalp abnormality.Infratentorial lesions and other lesions not closely associated with the overlyingscalp abnormality, such as those found in the cerebellum, have been reported,but are extremely uncommon. We present a case of an 8-year-old boy with a left fronto-parietal “en coup de sabre” scalp lesion and describe the neuroimaging findings of a progressively enlarging left cerebellar lesion discovered incidentally on routine magnetic resonance imaging. Interestingly, the patient had no neurologic symptoms given the size of the mass identified

Evaluation of the accuracy of working length determination and automatic apical reverse function accuracy of endodontic rotary motor integrated apex locator: an in-vitro study

Background: The outcome of a Root canal therapy depends upon complete cleaning of the root canal system without damaging periapical integrity. Accurate determination of working length determination is essential. The development of Endodontic motor integrated apex locators (EALs) for locating canal terminus has been significant innovation in the field of Endodontics. Aim: To evaluate the accuracy of Endomotor integrated electronic apex locator in determining the working length before and after cleaning and shaping with Automatic Apical Reverse action set at the "0.5mm" mark. Methodology: Forty extracted premolars were decoronated, patency was verified. The actual length of tooth measured and teeth were embedded in alginate and file was advanced. Readings at the apex and 0.5mm short of the apex was recorded using Dentaport ZX (DZ group) and EConnect S (ES group) apex locator. Cleaning and shaping were done with rotary files with Automatic Apical Reverse action set at 0.5mm short of apex and reading recorded as Automatic Apical Reverse Length (AARL), and actual tooth length is measured. The data obtained were statistically analyzed. Results: Within the limitations of the study, the EALs readings of the DZ group & ES group provided an acceptable determination of working length within range ± 0.5mm, and AAR function set at 0.5mm mark of Endomotor integrated apex locator (E Connect S) provided an adequate apical limit. Conclusion: Under the invitro conditions of this study, both Electronic Apex Locators showed an acceptable determination of working length within range ± 0.5mm from the actual length. The AAR function set at the 0.5mm mark of Econnect S provided an adequate apical limit

Enhancement of Drugs Bioavailability by Floating Drug Delivery System – A Review

Gastric emptying is a complex process and one of the most important obstacles in the better absorption and enhances bioavailability of oral drug delivery system. In recent years various scientific and technological advancements have been made in the research and development of oral drug delivery systems to overcoming physiological adversities, such as short gastric residence times (GRT) and unpredictable gastric emptying time (GET). In order to avoid such adversities, efforts have been made to increase the retention time of the drug-delivery systems for more than 12 hour via floating drug delivery system. Floating delivery systems or hydro dynamically controlled systems are low density systems that have sufficient buoyancy to float over the gastric content and remain buoyant in the stomach. The recent development of these systems includes their physiological and formulation variables affecting the gastric retention and to design the single and multiple-unit floating systems and their formulation, evaluation aspects are covered in detail. This article aims at reviewing the numerous techniques that has been designed till date for optimizing floating drug delivery system (FDDS), and also summarize the evaluation of FDDS of tablet dosage forms

Chitosan Based Unidirectional Release Buccal Patches of Carbamazepine: Formulation Development and In Vitro, Ex Vivo Characterization

ABSTRACT The unidirectional release buccal patches of carbamazepine (CBZ) were designed in total of 36 formulations using a 3 2 full factorial design. Different hydrophilic polymers were used in the formulation along with chitosan-HPMC matrix. The thickness of the prepared patches varied between 0.3 ± 0.10 and 0.5 ± 0.15 mm. The mass of the patches varied from 142.4 ± 0.22 and 160.2 ± 0.13 mg. The pH of the prepared patches was in the range of 4.9±0.01 to 6.2±0.06. The drug loading efficiency of the patches varied between 18.1±0.5 and 19.8±0.1 and showed folding endurance of ˃188. Out of these 36 formulations, five formulations (FA42, FA46, FB38, FB49 and FB52) showed high folding endurance of ˃255. These patches were selected for further evaluation such as swelling studies, ex vivo mucoadhesion time, ex vivo mucoadhesive strength, in vitro drug release, ex vivo permeation, accelerated stability studies, DSC, FTIR and X-ray diffraction spectral studies. The percentage of swelling was higher up to 53 ± 1.1 for FB49 after 160 min. The percentage swelling was increased in the following order, FA42 < FB38 < FA46 < FB52 < FB49. The ex vivo mucoadhesion time of selected buccal patches was in the range of 112 ± 3.9 to 167 ± 3.1 min. The highest mucoadhesive force was observed with formulation FA42. In vitro release revealed that formulation FB49 showed maximum release of 99.9% after 90 min and followed by FB52 (105 min), FA46 (135 min), FB38 and FA42 (150 min). CBZ permeation through the porcine buccal mucosa was investigated by using Franz diffusion cell. There was a good correlation between in vitro drug release and ex vivo permeation studies. The accelerated stability study of tested patches showed no significant change in drug content, mucoadhesion time and surface pH, observed in the beginning of the study

Anion-transport mechanism of a triazole-bearing derivative of prodigiosine: a candidate for cystic fibrosis therapy

Cystic fibrosis (CF) is a genetic lethal disease, originated from the defective function of the CFTR protein, a chloride and bicarbonate permeable transmembrane channel. CF mutations affect CFTR protein through a variety of molecular mechanisms which result in different functional defects. Current therapeutic approaches are targeted to specific groups of patients that share a common functional defect. We seek to develop an innovative therapeutic approach for the treatment of CF using anionophores, small molecules that facilitate the transmembrane transport of anions. We have characterized the anion transport mechanism of a synthetic molecule based on the structure of prodigiosine, a red pigment produced by bacteria. Anionophore-driven chloride efflux from large unilamellar vesicles is consistent with activity of an uniporter carrier that facilitates the transport of anions through lipid membranes down the electrochemical gradient. There are no evidences of transport coupling with protons. The selectivity sequence of the prodigiosin inspired EH160 ionophore is formate > acetate > nitrate > chloride > bicarbonate. Sulfate, phosphate, aspartate, isothionate, and gluconate are not significantly transported by these anionophores. Protonation at acidic pH is important for the transport capacity of the anionophore. This prodigiosin derived ionophore induces anion transport in living cells. Its low toxicity and capacity to transport chloride and bicarbonate, when applied at low concentration, constitute a promising starting point for the development of drug candidates for CF therapy.European Union’s Horizon 2020 research and innovation programme under grant agreement No 667079 and Consejería de Educación de la Junta de Castilla y León (Project BU092U16)

Insertion of Isocyanides into N-Si Bonds: Multicomponent Reactions with Azines Leading to Potent Antiparasitic Compounds.

Trimethylsilyl chloride is an efficient activating agent for azines in isocyanide-based reactions, which then proceed through a key insertion of the isocyanide into a N-Si bond. The reaction is initiated by N activation of the azine, followed by nucleophilic attack of an isocyanide in a Reissert-type process. Finally, a second equivalent of the same or a different isocyanide inserts into the N-Si bond leading to the final adduct. The use of distinct nucleophiles leads to a variety of α-substituted dihydroazines after a selective cascade process. Based on computational studies, a mechanistic hypothesis for the course of these reactions was proposed. The resulting products exhibit significant activity against Trypanosoma brucei and T. cruzi, featuring favorable drug-like properties and safety profiles