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T Doğanay

Publications and source records attributed to T Doğanay.

3 recordsLinked to original sources

Dissolution and assaying of multicomponent tablets by chemometric methods using computer-aided spectrophotometer.

Dissolution of three component tablets containing paracetamol (APAP), propyphenazone (PP), and caffeine (CAF) was carried out by USP paddle method. Three chemometric methods; inverse least square (ILS), principal component regression (PCR) and partial least squares (PLS) were applied to simultaneous assay of APAP, PP and CAF in tablets. The PCR, PLS and ILS methods were applied to simultaneous dissolution APAP, PP and CAF in tablets using a double beam UV-Vis spectrophotometer without any chemical separation and any graphical treatment of the overlapping spectra of three drugs. Twenty two mixture solutions in different concentrations were prepared in simulated gastric juice (SGJ, USP) for the chemometric calibrations as training set. The absorbance data matrix was obtained by measuring the absorbance at 14 wavelength points (from 222.5 to 292.5 nm) with the intervals of 5 nm (Deltalambda=5 nm) in the spectral region between 200 and 310 nm. Training set and absorbance data were used for the calibrations of chemometric methods. The developed calibrations were tested for the previously prepared solutions of mixture of three drugs for the validation of the assay method. The chemometric calculations were performed by using the 'MAPLE VRSQUO; software. The results of three chemometric methods were statistically compared with each other. These chemometric calibrations were successfully applied to the content uniformity and dissolution of the multicomponent tablets without any separation procedure. The synthetic mixtures of three drugs were used for the validity of the calibrations. Means recoveries (percent) and relative standard deviation of PLS, PCR and ILS methods were found to be 100.1+/-0.6, 101.4+/-1.6 and 100.1+/-0.6 for APAP; 100.9+/-3.2, 102.0+/-3.3 and 100.9+/-3.2 for PP; 99.9+/-3.5, 101.6+/-3.3 and 99.9+/-3.2 for CAF, respectively. Dissolution profiles of three component tablets were performed. More than 95% of drugs were dissolved within 15 min. All of the three-chemometric methods in this study can be satisfactorily used for the quantitative analysis and for dissolutions test of multicomponent dosage form.

Numerical Analysis, Computer-Assisted↗

Comparison of the antibacterial effects on subgingival microflora of two different resorbable base materials containing doxycycline.

A study was conducted to evaluate the effects of local drug delivery on subgingival plaque flora using hydroxypropylmethylcellulose (HPMC) and methylcellulose (MC) base material containing 40% doxycycline (DOXY). Eleven patients who had at least four pockets exceeding 5 mm in depth associated with a single rooted tooth were selected from volunteers after an initial examination. Two of the pockets were chosen at random for insertion of the HPMC and MC strips twice a week for 6 w. One pocket received no treatment, and the other was debrided and root-planed only. Baseline and follow-up measurements at 0, 1, 3, 6, and 10w included probing depth, gingival shrinkage, bleeding on probing and crevicular fluid flow. Subgingival bacterial samples were also taken for dark-field microscopy. In vitro drug release from the HPMC strips was greater than that from MC. Significant improvements in many clinical parameters occurred in the pockets treated with HPMC or MC strips, or mechanical debridement. There was a marked decrease in the relative proportions of motile organisms during and after treatment.

Adult↗

Use of membranes containing 20% chlorhexidine and 40% doxycycline for treatment of chronic periodontal pockets.

A study was carried out to compare the effects of subgingival applications of resorbable hydroxypropylmethylcellulose (HPMC) membranes containing 20% chlorhexidine (CHx) and 40% doxycycline (DOXY) placed subgingivally in periodontal pockets greater than 5 mm in depth. Each of 11 patients had at least four pockets. HPMC strips containing CHx and DOXY were inserted into each pocket twice a week for 6 w. One pocket was kept as a control and the other received subgingival scaling and root planing at 0, 1, 3 and 6 w. The microbial flora of 44 pockets from the 11 patients was examined using dark-field microscopy at the baseline and at 1, 3, 6 and 10 w. Clinical parameters including probing depth, crevicular fluid flow, bleeding on probing and gingival shrinkage were also recorded. The CHx and DOXY-administered or root-planed pockets showed marked reduction of both pocket depth and the number of motile organisms. Less bleeding was also observed in CHx and DOXY-inserted pockets.

Adult↗