Tranexamic acid effects in postoperative bleeding outcomes in laparoscopic sleeve gastrectomy: a controlled study

Purpose: To demonstrate through a controlled study whether the use of tranexamic acid in bariatric surgeries is effective for bleeding control. Methods: Prospective, comparative, and double-blind study performed with patients from 18 to 65 years old submitted to bariatric surgery. The selected patients received venous tranexamic acid (TXA) during the induction of anesthesia or not (CG). The anesthesia and thromboprophylaxis protocols were similar among the groups. For statistical analysis, the χ2 and analysis of variance tests were performed at a significance level of p < 0.05, using the statistical program SPSS 21.0®. Results: Sixty-one patients were included in the study, 31 in the control group and 30 in the TXA group (GTXA). In the intraoperative period, the bleeding volume was greater in the CG than in the GTXA. In the postoperative period, the tranexamic acid group had a higher value hematocrit, absence of surgical reoperations due to bleeding complications, and shorter hospitalization time than the control group. Conclusions: The use of tranexamic acid was effective in reducing bleeding rates and of hospital stay length, in addition to demonstrating the clinical safety of its use, for not having been associated with any thromboembolic events.

Validation of the Developed Zero-Order Infrared Spectrophotometry Method for Qualitative and Quantitative Analyses of Tranexamic Acid in Marketed Tablets.

(1) Background: The functional groups present in tranexamic acid allow direct infrared detection analysis. This study aimed to develop, apply, and validate an infrared spectrophotometry method used for qualitative and quantitative analyses of tranexamic acid in marketed tablets. (2) Methods: This was a descriptive observational study that consisted of several stages: determining the specific wavenumber for analysis, obtaining a simple linear regression equation, analyzing tranexamic acid both qualitatively and quantitatively, and validating the developed method for routine analysis. (3) Results: The peak analysis obtained a range of baseline wavenumbers from 1679.17 to 1295.25 cm-1. The regression equation obtained was Y = 310.8527 × X + 0.9718, and the coefficient of determination (R2) obtained was 0.9994. The tranexamic acids in marketed tablets overall have a similarity index value of more than 0.90 and overall have levels ranging between 97.0% and 103.0%. The infrared spectrophotometry method that was successfully developed, applied, and validated for qualitative and quantitative analyses of tranexamic acid in marketed tablets meets the requirements both qualitatively and quantitatively of the tablet monograph. (4) Conclusions: The infrared spectrophotometry method has been validated and meets the requirements for accuracy, precision, detection limit, quantitation limit, linearity, range, and specificity.

[Determination of tranexamic acid in essential cosmetics by pre-column derivatization capillary electrophoresis coupled with electrogenerated chemiluminescence detection].

N-Methylation of tranexamic acid yields an unique derivative, which generates strong co-luminescence signals in the presence of an electrochemiluminescence reagent such as Ru(bpy)32+. Using this principle, we established a highly selective analytical method based on pre-column derivatization capillary electrophoresis coupled with electrogenerated chemiluminescence detection for determining the tranexamic acid content in essential cosmetics. The addition of a ternary ionic association gel, Mg2+-trehalose-SiO32-, in the components of background electrolyte greatly improved the electrophoretic separation efficiency. Under the optimized assay conditions, two electrophoretic peaks attributed to the derivatives of tranexamic acid and its internal standard (sarcosine) were completely separated in 500 s, and their electrophoretic peak intensities ratio showed a good linear relationship with the initial concentration of tranexamic acid in the range of 10-750 µmol/L (correlation coefficient r2=0.9993). The limit of detection was estimated to be 3.6 µmol/L (S/N=3). Moreover, the internal standard method was further applied to the quantitative determination of tranexamic acid content in three kinds of toothpaste and two kinds of nutrient solutions in facial masks. The results showed that the average tranexamic acid content in three toothpaste samples was 4.05, 0.24, and 6.06 mg/g, while that in two facial masks was 51.3 and 7.98 mg/mL. The recoveries for the above-mentioned samples were within the range 92.5% to 104.0%, implying satisfactory results.

Skin permeation and retention of topical bead formulation containing tranexamic acid.

The objective of this study is to develop a topical bead formulation of tranexamic acid (TA) which can be used concomitantly with laser treatment. The bead formulation of TA (TAB) was successfully prepared by fluidized bed drying method. Physicochemical properties of the TAB were evaluated in terms of chemical stability of TA and differential scanning calorimetry. TA in the bead was stable up to six months at 25°C and existed as amorphous state. In vitro skin permeation and in vivo skin retention of TA in the beads were significantly higher compared to a commercial product. When the bead was dissolved into distilled water and applied concomitantly with laser treatment, the amount of TA retained in the skin in the in vivo study was inversely proportional to the energy levels of laser treatment, indicating absorption into subcutaneous tissue and drainage to systemic circulation. Therefore, when laser treatment is used concomitantly with TAB, energy level should be very carefully monitored to avoid possible adverse events associated with systemic side effects of TA.

Eliminating the use of allogeneic blood products in adolescent idiopathic scoliosis surgery.

PURPOSE: The aim of this study was to compare transfusion requirements in patients before and after the introduction of tranexamic acid as standard in patients undergoing spinal surgery for idiopathic scoliosis in a national orthopaedic hospital. METHODS: A retrospective chart review of 56 idiopathic scoliosis patients who underwent posterior spinal instrumentation and fusion between 2009 and 2013 at our institution. Preoperative, intraoperative, and postoperative data were measured. RESULTS: Patients who received tranexamic acid as standard (n = 31) showed a trend towards a decrease in transfusion requirements compared with those who received no tranexamic acid (n = 25). These patients had a statistically significant decrease in operative time (223 vs 188 min, p = 0.005), and estimated intraoperative blood loss was reduced by nearly 50% in the tranexamic acid group. They also had an associated reduced decrease in haemoglobin between preoperative and postoperative levels (4 vs 5 g/dL, p = 0.01). CONCLUSIONS: Since February 2012, no patient has required intraoperative or postoperative allogeneic blood product transfusion in this hospital. The routine use of antifibrinolytic medications in patients undergoing surgery for adolescent idiopathic scoliosis has effectively eliminated the need for allogeneic blood products.

Determination of tranexamic acid in various matrices using microwave-assisted derivatization followed by dispersive liquid-liquid microextraction.

Tranexamic acid (TA) is widely used to treat medical hemorrhagic conditions and as a whitening agent in cosmetic products. The aim of this study was to develop a micro-analytical method of determining TA in widely varying sample matrices, including pharmaceuticals, cosmetics, extracts of the stratum corneum, human keratinocyte cells, and human plasma. Using dansyl chloride as the derivatizing reagent in the pretreatment reduced the reaction time to within 4min in combined microwave-assisted reaction. To prevent excess dansyl chloride and sample matrices from damaging the column, 4µL chloroform was used to remove excess derivatizing agent and interference through dispersive liquid-liquid microextraction (DLLME) method. After pretreatment, 1µL of sample solution was injected in capillary liquid chromatography coupled with ultraviolet detector (CapLC-UV). By coupling the proposed method with cylinder-sampling method, TA was successfully extracted from the stratum corneum. The calibration curves for the standard solution and human plasma were in the ranges of 0.1-50µM and 5-500µM, respectively. Both calibration curves had correlation coefficients (r(2)) of 0.999. The limits of detection were 0.03pmol in standard solution and 3pmol in plasma. Compared to non-derivatized TA, the use of CapLC-UV for detecting derivatized TA provides a 1000-fold sensitivity improvement.

Spectrophotometric determination of tranexamic acid using vanillin.

A new spectrophotometric method has been examined for the determination of the tranexamic acid (TA) by derivatization with vanillin (VAN). The molar absorptivity of TA was calculated 25,160 L x mol(-1) x cm(-1) at lambdamax 354 nm and obeyed the Beer's law within 0.5-2.5 microg x mL(-1). The color reaction was highly stable and did not show any change in absorbance up to 24 h. The method was applied for the analysis of TA from capsules, injections and tooth pastes. The amounts of TA found in capsules, injections and tooth pastes of various pharmaceutical companies were observed with 249.0-250.9 mg/capsule, 249.3-250.7 mg/injection and 0.048%-0.049% in tooth pastes with relative standard deviation (RSD) 0.2%-5.0% (n = 3).

Spectrophotometric determination of tranexamic acid in pharmaceutical bulk and dosage forms.

In this study, a simple, fast, accurate and sensitive spectrophotometric method has been developed for the determination of tranexamic acid in bulk and pharmaceutical preparations. The method is based on the reaction of ninhydrin with the primary amino group of tranexamic acid in the basic medium at pH 8.0. The reaction produces a bluish-purple color which absorbs maximally at 565 nm. Beer's law was obeyed in the range of 3-40 microg ml(-1) with molar absorptivity of 5.093 x 10(3) L mol(-1) cm(-1). The effects of various factors such as temperature, heating time, concentration of reagent, color stability and interferences were investigated to optimize the procedure. The results have been validated analytically and statistically. The proposed method has been applied for the determination of tranexamic acid in bulk and pharmaceutical preparations with good results.

In vivo biological performance of composites combining micro-macroporous biphasic calcium phosphate granules and fibrin sealant.

INTRODUCTION: Fibrin glues are currently used by surgeons and can facilitate the handling of biomaterials. Combining fibrin glue with calcium phosphate bioceramics gives a mouldable composite that cements the granules into the implantation site. In addition to the mechanical aspect of the composite, it has been suggested that the mixture also promotes wound healing. These human blood derivatives contain natural (aprotinin) or synthetic (tranexamic acid) antifibrinolytic substances. We compared the bioactivity of two composites combining calcium phosphate granules with two different types of fibrin glue, one with aprotinin and the other with tranexamic acid. MATERIALS AND METHODS: The composite was composed of fibrin glue (Tissucol) and 1 to 2 mm granules of biphasic calcium phosphate granules (MBCP) with a volume ratio of 1 for 2. Bone cavities were drilled in 12 New Zealand rabbits and filled with a composite with aprotinin-fibrin glue on the right condyle and one with tranexamic acid-fibrin glue on the left condyle. The rabbits were randomized into two groups: 3 and 6 weeks of delay. Light microscopy, scanning electron microscopy and image analysis were performed. RESULTS: No adverse reactions were observed in either sample. Bony ingrowth associated with bioceramic resorption by osteoclastic TRAP-positive cells was noted. No significant difference was observed between the two composites. The bony ingrowth and ceramic resorption were qualitatively and quantitatively similar with both composites. CONCLUSION: This study demonstrated that the choice of a natural (aprotinin) or synthetic (tranexamic acid) antifibrinolytic agent in the fibrin sealant associated with calcium phosphate granules and used as a bone substitute had no effect on the bioactivity of the composite. It remained efficient in bone reconstruction, no adverse effects were observed, and the bony ingrowth was qualitatively and quantitatively equivalent with the two types of fibrin sealant.

Determination of vigabatrin in human plasma and urine by high-performance liquid chromatography with UV-Vis detection.

A simple and reliable high-performance liquid chromatographic (HPLC) method with UV-Vis detection has been developed and validated for the determination of vigabatrin (VG) in human plasma and urine. The samples were pre-column derivatizated with 1,2-naphthoquinone-4-sulphonic acid sodium salt (NQS). A good chromatographic separation was achieved on a C18 column with a mobile phase consisting of acetonitrile and 10 mM orthophosphoric acid (pH 2.5) gradient elution. Tranexamic acid was used as an internal standard (I.S.). The method was linear over the concentration range of 0.8-30.0 microg/ml for both samples. The method is precise (relative standard deviation (R.S.D.) <9.13%) and accurate (relative mean error (RME) <-8.75%); analytical recoveries were 81.07% for plasma and 83.05% for urine. The assay was applied to pharmacokinetic study in a healthy volunteer after a single oral administration of 1 g of vigabatrin.

Partial purification, and some properties and reactivities of cetraxate benzyl ester hydrochloride-hydrolyzing enzyme.

Debenzylating enzyme from Aspergillus niger enzyme (commercial crude cellulase) catalyzes the hydrolysis of cetraxate benzyl ester hydrochloride (2), a precursor of the antiulcer agent (1). The enzyme was highly purified by three kinds of chromatographies (hydrophobic, ion exchange, gel filtration) with a recovery of 36%. The content of the debenzylating enzyme was about 0.1% in the crude cellulase, but the enzyme showed no cellulase activity. The purified enzyme was inactivated by Hg2+, and diisopropyl phosphorofluoridate (DFP). It was a monomer with a molecular weight of about 35,000, and its isoelectric point was estimated to be 5.3. It showed a debenzylating activity for the phenylpropionic acid benzyl ester moiety of various benzyl ester derivatives, and the benzyl ester of phenylalanine or that of tyrosine was also well hydrolyzed.

Control of Arthus tonsillitis by the administration of an antiplasminic agent.

Previous reports have shown that fibrinolytic activity was increased in the circulatory blood of rabbits with Arthus tonsillitis. In this study, t-AMCHA was administered intravenously to rabbits, in order to clarify its role as an antiplasminic agent in the control of Arthus tonsillitis. First, to establish the proper method of administration of t-AMCHA and the quantity to be administered, a preliminary estimation was made of the requisite concentration of t-AMCHA in the circulating blood and tonsillar tissue. Then macroscopic observations and histopathological studies were performed on the tonsils of rabbits with Arthus tonsillitis after t-AMCHA administration at various doses. Finally, after injection of the antiplasminic agent, estimations were made of the plasma fibrinolytic activity in the blood of the rabbits under study. It was decided that administration of t-AMCHA at 3-hourly intervals could maintain a constant concentration of the substance in the tonsillar tissue. The marked hyperaemia and bleeding which were observed macroscopically and histopathologically at 1-2 days after the onset of tonsillitis, disappeared from the parenchyma of the tonsils and pharyngeal tissue surrounding the tonsils in the group receiving regular injections of t-AMCHA at 3-hourly intervals. After estimating certain parameters of the fibrinolytic system in the blood, it was found that fibrinolytic activity decreased and whole plasmin was not consumed as a result of the administration of t-AMCHA during the early stage of tonsillitis. The process of Arthus tonsillitis can thus be controlled by the administration of the antiplasminic agent.

Diffusion of tranexamic acid to the joint.

Tranexamic acid (Cyklokapron, Kabi, Stockholm) in a dose of 10 mg per kg body weight was given i.v. to 17 patients at various intervals before operation on the knee joint, in order to elucidate the diffusion of the drug to the joint fluid and the synovial membrane. The acid diffused rapidly to both the above tissues, and in the joint fluid it reached the same concentration as in the serum. The biologic half-time in the joint fluid was about 3 hours. In the treatment of joint bleedings in hemophiliacs and in association with intra-articular operations on such patients tranexamic acid is a suitable supplement to conventional substitution therapy.