Bioadhesive polymeric platforms for transmucosal drug delivery systems – a review

Of the various routes of drug delivery, the oral route is often preferred by the patient. However, peroral administration of drugs has disadvantages such as hepatic first-pass metabolism and enzymatic degradation within the gastrointestinal tract which constitutes a hindrance to oral administration of certain classes of drugs, especially peptides and proteins. Consequently, other absorptive mucosae are often considered as potential sites for drug administration. Transmucosal routes of drug delivery (i.e., the mucosal linings of the nasal, rectal, vaginal, ocular, and oral cavity) offer distinct advantages over peroral administration for systemic drug delivery. These advantages include possible bypass of firstpass effect, avoidance of presystemic elimination within the GI tract, and, depending on the particular drug, better enzymatic flora for drug absorption. However, the mucosa surface as a site for drug delivery has limitations as well. Other than the low flux associated with mucosal delivery, a major limitation of the transmucosal route of administration is the lack of dosage form retention at the site of absorption. Consequently, bioadhesive polymers have extensively been employed in transmucosal drug delivery systems. If these materials are then incorporated into pharmaceutical formulations, drug absorption by mucosal cells may be enhanced or the drug may be released at the site for an extended period of time. This review describes various bio/mucoadhesive polymers used in transmucosal drug delivery. Starting with introduction of bioadhesion with theories and mechanism, history, different bioadhesive polymers, characteristics of desired bioadhesive polymers, this article then proceeds to cover the various sites suitable for mucoadhesive drug delivery system followed by the factors affecting bio/ mucoadhesion.Keywords: Mucosa; Tansmucosal delivery; Bioadhesion; Lectin; Polymers; Thiomer; Fimbrin

Economic Feasibility of Vegetable Production under Polyhouse:A Case Study of Capsicum and Tomato

Polyhouse cultivation of vegetables is emerging as a specialized production technology to overcome biotic and abiotic stresses and to break the seasonal barrier to production. It also ensures round the year production of highvalue vegetables, like capsicum, especially, during off-season. Cost is the major issue in sustaining this technology. The present study examined the economic viability of production of capsicum and tomato in a naturally ventilated polyhouse of medium cost category with drip irrigation system. Data were generated by cost accounting method for estimating the feasibility of production and was analyzed by using project evaluation methods, like Pay Back Period (PBP), Benefit Cost Ratio (BCR), Net Present Value (NPV) and Internal Rate of Return (IRR). Cultivation of capsicum in a polyhouse was found to be highly feasible as reflected in higher values of NPV (Rs.3,23,145/500 m2), BCR (1.80) and IRR (53.7%) with payback period of less than two years. Breakeven price for capsicum production in a polyhouse (Rs.11.80/kg) was lesser than average wholesale price. Production of tomato in a polyhouse was found not feasible, as the breakeven price was more than the average market price and all the project appraisal parameters indicated that it was not feasible. Only at about 48% premium price over the prevailing market price or reduction of cost of polyhouse structure by 60% from Rs.400 to Rs.160 /m2, could make the tomato production viable in a poly house

Invitro Antimicrobial Activity and Phytochemical Analysis of Ficus religiosa L. and Ficus bengalensis L. against Diarrhoeal Enterotoxigenic E. coli

The barks of Ficus religiosa L. and Ficus bengalensis L., which belongs to family Moraceae, were investigated for invitro antibacterial activity and phytochemical analysis. The various solvents extract like aqueous, methanol, chloroform, petroleum ether and hexane were screened for antibacterial activity against Enterotoxigenic E. coli isolated from diarrhoeal patients. The preliminary phytochemical analysis of the methanol extracts of both the plants showed the presence of carbohydrates, flavonoids, aminoacids, steroids, saponins and tannins. The extracts were subjected for antibacterial activity against Enterotoxignic E.coli (ETEC) at 200mg/ml concentration by disc diffusion method. The results of antibacterial activity revealed that methanol extracts of both the plants barks exhibits good activity compared to chloroform and aqueous extracts. Petroleum ether and hexane extracts did not show any activity. The antibacterial activities of extracts were compared with standard antibiotics

Gaussian approximation for finitely extensible bead-spring chains with hydrodynamic interaction

The Gaussian Approximation, proposed originally by Ottinger [J. Chem. Phys., 90 (1) : 463-473, 1989] to account for the influence of fluctuations in hydrodynamic interactions in Rouse chains, is adapted here to derive a new mean-field approximation for the FENE spring force. This "FENE-PG" force law approximately accounts for spring-force fluctuations, which are neglected in the widely used FENE-P approximation. The Gaussian Approximation for hydrodynamic interactions is combined with the FENE-P and FENE-PG spring force approximations to obtain approximate models for finitely-extensible bead-spring chains with hydrodynamic interactions. The closed set of ODE's governing the evolution of the second-moments of the configurational probability distribution in the approximate models are used to generate predictions of rheological properties in steady and unsteady shear and uniaxial extensional flows, which are found to be in good agreement with the exact results obtained with Brownian dynamics simulations. In particular, predictions of coil-stretch hysteresis are in quantitative agreement with simulations' results. Additional simplifying diagonalization-of-normal-modes assumptions are found to lead to considerable savings in computation time, without significant loss in accuracy.Comment: 26 pages, 17 figures, 2 tables, 75 numbered equations, 1 appendix with 10 numbered equations Submitted to J. Chem. Phys. on 6 February 200

Myc-binding Protein Orthologue Interacts with AKAP240 In the Central Pair Apparatus of the \u3cem\u3eChlamydomonas\u3c/em\u3e Flagella

Background Flagella and cilia are fine thread-like organelles protruding from cells that harbour them. The typical ‘9 + 2’ cilia confer motility on these cells. Although the mechanistic details of motility remain elusive, the dynein-driven motility is regulated by various kinases and phosphatases. A-kinase anchoring proteins (AKAPs) are scaffolds that bind to a variety of such proteins. Usually, they are known to possess a dedicated domain that in vitro interacts with the regulatory subunits (RI and RII) present in the cAMP-dependent protein kinase (PKA) holoenzyme. These subunits conventionally harbour contiguous stretches of a.a. residues that reveal the presence of the Dimerization Docking (D/D) domain, Catalytic interface domain and cAMP-Binding domain. The Chlamydomonas reinhardtii flagella harbour two AKAPs; viz., the radial spoke AKAP97 or RSP3 and the central pair AKAP240. Both these were identified on the basis of their RII-binding property. Interestingly, AKAP97 binds in vivo to two RII-like proteins (RSP7 and RSP11) that contain only the D/D domain. Results We found a Chlamydomonas Flagellar Associated Protein (FAP174) orthologous to MYCBP-1, a protein that binds to organellar AKAPs and Myc onco-protein. An in silico analysis shows that the N-terminus of FAP174 is similar to those RII domain-containing proteins that have binding affinities to AKAPs. Binding of FAP174 was tested with the AKAP97/RSP3 using in vitro pull down assays; however, this binding was rather poor with AKAP97/RSP3. Antibodies were generated against FAP174 and the cellular localization was studied using Western blotting and immunoflourescence in wild type and various flagella mutants. We show that FAP174 localises to the central pair of the axoneme. Using overlay assays we show that FAP174 binds AKAP240 previously identified in the C2 portion of the central pair apparatus. Conclusion It appears that the flagella of Chlamydomonas reinhardtii contain proteins that bind to AKAPs and except for the D/D domain, lack the conventional a.a. stretches of PKA regulatory subunits (RSP7 and RSP11). We add FAP174 to this growing list

Pilot scale studies on the beneficiation of complex sulphides by flotation column

Experiments using pilot size flotation Column as cleaner cell were conducted to evolve a suitable flow sheet for the production of bulk sulphide concentrates of Cu-Pb-Zn. The flotalion circuit consisting of roughing, scavenging, and two stage cleaning by conventional flotation machines was compared with the circuit where two stage cleaning operation was replaced with single stage cleaning by flotation column. It is clearly demonstrated that a single stage cleaning by flotation column is more efficient and sufficient to obtain bulk concentrate suitable for further processing. Of the two types of sparger systems used viz, TURBO and MICROCEL, the former was found to be better to achieve high quality concentrate

Acoustical-Mode-Driven Electron-Phonon Coupling in Transition-Metal Diborides

We show that the electron-phonon coupling in the transition-metal diborides NbB2 and TaB2 is dominated by the longitudinal acoustical (LA) mode, in contrast to the optical E_{2g} mode dominated coupling in MgB2. Our ab initio results, described in terms of phonon dispersion, linewidth, and partial electron-phonon coupling along Gamma to A, also show that (i) NbB2 and TaB2 have a relatively weak electron-phonon coupling, (ii) the E_{2g} linewidth is an order of magnitude larger in MgB2 than in NbB2 or TaB2, (iii) the E_{2g} frequency in NbB2 and TaB2 is considerably higher than in MgB2, and (iv) the LA frequency at A for TaB2 is almost half of that of MgB2 or NbB2.Comment: 4 pages, 4 figures, and 1 tabl

Circuit simplification by adopting flotation columns.

Pilot scale studics on the beneficiation of low-grade fluorspar and copper-lead-zinc ore were investigated using flotation columns. Acidspar concentrates suitable for HF production can be produced by adopting two-stage column cleaning in place of multi-stage cleaning by conventional flotation cells. A three-column canfiguration in the place of four-stage cleaning in acidspar circuit and four in metspar circuit was suggested. Similarly, it was demonstrated that a single stage cleaning by flotation column was found to be sufficient in the plnce of two-stage cleaning by conventional flotation cells to obtain bulk concentrates of Cu-Pb-Zn

Antimicrobial Activity and Phytochemical Analysis of Coriander sativum Against Infectious Diarrhea

The preliminary phytochemical study and invitro antimicrobial activity of Coriander sativum (Apiaceae) was investigated against some pathogens isolated from patients with infectious diarrhea. The various solvents extract like aqueous, methanol, chloroform, petroleum ether and hexane were screened for antimicrobial activity against Enterotoxigenic E.coli, Enteropathogenic E.coli,, Salmonella typhimurium, Salmonella entertidis, Shigella dysentriae, Shigella flexineri, Candida albicans, Candida tropicalis and Candida krusei isolated from diarrhoeal patients. The preliminary phytochemical analysis of the methanol extracts of the plant showed the presence of carbohydrates, flavonoids, aminoacids, steroids, sterols, saponins and tannins. The extracts were subjected for antimicrobial activity against at 200mg/ml concentration by disc diffusion method. The results of antimicrobial activity revealed that methanol extract of the plant exhibit good activity compared to chloroform and aqueous extracts to E.coli, Salmonella sp and Shigella sp. Petroleum ether and hexane extracts did not show any activity. None of extracts exhibits antifungal activity. The antimicrobial activities of extracts were compared with standard antibiotics