caa a22 4500 477127401 CHVBK 20180405111653.0 cr unu---uuuuu 170330e19970401xx s 000 0 eng 10.1023/A:1012091231023 doi (NATIONALLICENCE)springer-10.1023/A:1012091231023 Textural Analysis and Flow Rheometry of Novel, Bioadhesive Antimicrobial Oral Gels [Elektronische Daten] [David Jones, A. Woolfson, Andrew Brown] Purpose. This study examined the rheological and textural characteristics (hardness, compressibilty, adhesiveness and cohesiveness) of bioadhesive oral gels containing the antimicrobial agent chlorhexidine. Methods. Textural analysis was performed using a Stable Micro Systems texture analyser (model TA-XT 2) in texture profile analysis (TPA) mode. In this, an analytical probe was twice compressed into each formulation to a defined depth (15 mm) and at defined rates (2, 4, 6, 8, 10 mm s−1), allowing a delay period (15 s) between the end of the first and beginning of the second compressions. Flow rheograms were performed using a Carri-Med CSL2-100 rheometer with parallel plate geometry under controlled shearing stresses at 20.0 ± 0.1°C. Results. All formulations exhibited pseudoplastic flow with thixotropy. Increasing concentrations of each polymer significantly increased formulation hardness, compressibility, adhesiveness and zero-rate viscosity. Increased hardness and compressibility were due to the attendent increased viscosities of these formulations. Increased adhesiveness was related to the concentrations of the (bioadhesive) polymers employed in these formulations and, in addition, was dependent on the physical state of polycarbophil. Formulation viscosity contributed to product adhesiveness, reflecting the importance of product rheology on this parameter. Decreased formulation cohesiveness, observed as the concentrations of the PVP, PC and HEC (3−5%w/w) were increased, was due an increase in semi-solid character. Numerical values of hardness, compressibility and adhesiveness were affected by the choice of probe speed, a parameter related to rate of shear in flow rheometry. Statistical interactions were observed and were assigned to the effects of HEC on the physical state of PVP (dissolved or dispersed) and PC (swollen or unswollen). Conclusions. This study has demonstrated both the applicability of textural analysis for the mechanical characterisation of bioadhesive semi-solid gel systems and, additionally, the direct influence of viscosity on the parameters defined by textural analysis, namely, hardness, compressibility and adhesiveness. Plenum Publishing Corporation, 1997 texture profile analysis nationallicence bioadhesion nationallicence semi-solids nationallicence hardness nationallicence compressibility nationallicence adhesiveness nationallicence cohesiveness nationallicence flow rheometry nationallicence Jones David School of Pharmacy, The Queen's University of Belfast, Medical Biology Centre, 97, Lisburn Road, BT9 7BL, Northern Ireland, Belfast, U.K. aut Woolfson A. School of Pharmacy, The Queen's University of Belfast, Medical Biology Centre, 97, Lisburn Road, BT9 7BL, Northern Ireland, Belfast, U.K. aut Brown Andrew School of Pharmacy, The Queen's University of Belfast, Medical Biology Centre, 97, Lisburn Road, BT9 7BL, Northern Ireland, Belfast, U.K. aut Pharmaceutical Research Kluwer Academic Publishers-Plenum Publishers 14/4(1997-04-01), 450-457 0724-8741 14:4<450 1997 14 11095 https://doi.org/10.1023/A:1012091231023 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1012091231023 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Jones David School of Pharmacy, The Queen's University of Belfast, Medical Biology Centre, 97, Lisburn Road, BT9 7BL, Northern Ireland, Belfast, U.K aut NATIONALLICENCE 700 1- Woolfson A. School of Pharmacy, The Queen's University of Belfast, Medical Biology Centre, 97, Lisburn Road, BT9 7BL, Northern Ireland, Belfast, U.K aut NATIONALLICENCE 700 1- Brown Andrew School of Pharmacy, The Queen's University of Belfast, Medical Biology Centre, 97, Lisburn Road, BT9 7BL, Northern Ireland, Belfast, U.K aut NATIONALLICENCE 773 0- Pharmaceutical Research Kluwer Academic Publishers-Plenum Publishers 14/4(1997-04-01), 450-457 0724-8741 14:4<450 1997 14 11095 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer