Tableting properties of microcrystalline cellulose obtained from wheat straw measured with a single punch bench top tablet press.

The objective of this work was to study the relation between the manufacturing conditions of microcrystalline cellulose (MCC), its physicochemical properties and its tableting behavior. Two different preparation procedures were used to produce MCC from wheat straw, utilizing an acid hydrolysis method, either using only sulfuric acid or combination of sulfuric and hydrochloric acid. The tableting behavior of obtained MCC samples and mixtures of MCC with ibuprofen was studied using a dynamic powder compaction analyzer. It was observed that some of the obtained MCC samples showed better flowing properties than commercially available Vivapur® PH101 and also very high values of tensile strength, solid fraction and elastic recovery. This can be linked with its good compaction behavior, but on the other hand it can cause problems with the disintegration of the tablets. In mixtures with ibuprofen, MCC samples showed lower values of tensile strength, while on the other hand elastic recovery did not seem to be much affected, still exhibiting very high values. According to the obtained results, it can be concluded that MCC obtained from the agricultural waste could have satisfactory properties for tablet preparation by the direct compression method. Further studies are needed to optimize process conditions in order to achieve better physicochemical characteristics, especially in terms of elastic recovery.

Development of ternary solid dispersions with hydrophilic polymer and surface adsorbent for improving dissolution rate of carbamazepine.

In this study solid dispersions of carbamazepine in the hydrophilic Kollidon® VA64 polymer, adsorbed onto Neusilin® UFL2 adsorption carrier have been employed to improve carbamazepine dissolution rate. In order to evaluate effects of changing in the proportions of all solid dispersion components on carbamazepine dissolution rate, D-optimal mixture experimental design was used in the formulation development. From all prepared solid dispersion formulations, significantly faster carbamazepine dissolution was observed compared to pure drug. Ternary solid dispersions containing carbamazepine, Kollidon® VA64 and Neusilin® UFL2 showed superior dissolution performances over binary ones, containing only carbamazepine and Neusilin® UFL2. Proportion of Kollidon® VA64 showed the most profound effect on the amount of carbamazepine dissolved after 10 and 30 min, whereby these parameters increase upon increasing in Kollidon® VA64 concentrations up to the middle values in the studied range of Kollidon® VA64 concentrations. Physicochemical characterization of the selected samples using differential scanning calorimetry, FT-IR spectroscopy, powder X-ray diffraction and polarizing light microscopy showed polymorphic transition of carbamazepine from more thermodynamically stable monoclinic form (form III) to less thermodynamically stable triclinic form (form I) in the case of ternary, but not of binary solid dispersion formulations. This polymorphic transition can be one of the factors responsible for improving of carbamazepine dissolution rate from studied solid dispersions. Ternary solid dispersions prepared with Kollidon® VA64 hydrophilic polymer and Neusilin® UFL2 adsorption carrier resulted in significantly improvement of carbamazepine dissolution rate, but formation of metastable polymorphic form of carbamazepine requires particular care to be taken in ensuring product long term stability.

Risk factors for recurrent vulvovaginal candidiasis.

BACKGROUND/AIM: Recurrent vulvovaginal candidiasis is relatively frequent condition, and may have serious health consequences, like chronic vulvovaginal pain syndrome. The aim of our study was to determine possible risk factors for recurrent vulvovaginal candidiasis in non-pregnant females within the reproductive age. METHODS: The design of our study was of a case-control type. Case and control patients were selected from the gynecological patients at six primary care facilities in Serbia and in Montenegro. The data on the patients' health condition, concomitant therapy and diseases were taken from their records, and the data on habits were obtained by unstructured interview. For potential risk factors crude odds ratios were calculated, and then adjusted by logistic regression. RESULTS: A total of fifty-one patients had four or more episodes of vulvovaginal candidiasis during the last year (cases), and 132 patients with one to three episodes of vulvovaginal candidiasis were sampled as controls, matched by age. The only two significant associations were found between recurrent vulvovaginal candidiasis and continual wearing of panty liners during the last year (Odds ratio - OR adjusted: 3.97; confidence interval--CI: 1.57-10.02;p = 0.004), and between recurrent vulvovaginal candidiasis and predominant use of vaginal tampons during menstruation in the last year (OR adjusted: 4.25; CI: 1.11-16.27;p = 0.035). The synergistic effect was observed for the concurrent continual wearing of panty liners during the last year and self-medication with antimycotics. CONCLUSIONS: Local factors, like wearing of panty liners or use of tampons during menstruation, may promote recurrence of vulvovaginal candidiasis, especially in patients who practice self-medication with antimycotics.