The Influence of Gum Arabic Admixture on the Mechanical Properties of Lime-Metakaolin Paste Used as Binder in Hemp Concrete

Organic admixtures based on polysaccharides are used in construction for modifying the properties of mortars and concretes. Gum arabic is an example of a polysaccharide-based biopolymer. The aim of the article was to investigate the possibilities of improving the strength parameters of a binder paste based on hydrated lime and metakaolin. The paste was modified with powdered gum arabic at 1%, 3% and 5% (by mass) as a partial replacement for the binder mix. The influence of the admixture on the pore size distribution as well as flexural and compressive strength was investigated. The admixture enhanced the total porosity of the paste, increasing the pore diameter compared with the reference formulation. The increase in porosity, in turn, did not reduce the mechanical strength. Conversely, the admixture in the amount of 3% and 5% caused a significant increase in the flexural (by about 300% in relation to reference paste) and compressive strengths (by 25% and 60%, respectively). The tested pastes were used as a binder in a composite based on hemp shives. The influence of binder modification on the water absorption and compressive strength of hemp concrete was tested. The strength of the composite soaked in water was also tested. The modification of the binder with gum arabic in the amount of 3% and 5% increased the compressive strength of hemp concrete (not soaked in water) by 53% and 92%, respectively and reduced the mass absorptivity by 6.6% and 10.4%, respectively.

Formulation and Development of Metoprolol Succinate Sustained Release Matrix tablet using Remusatia vivipara tubers mucilage

The purpose of this research was to formulate and evaluate sustained release tablet by using novel polymer Remusatia vivipara tubers mucilage. Currently natural gums and mucilages are being used extensively comparable to synthetic drug release modifiers. Natural plant materials possess various advantages. These are very cheap, biocompatible, biodegradable and free from side effects. In present research Metoprolol succinate matrix tablets were prepared by using Remusatia vivipara tubers mucilage. For the formulation of sustained release matrix tablets, direct compression method was used. The formulated matrix tablets were then evaluated for thickness, diameter, hardness, weight variation, friability, drug content, swelling index, in-vitro drug release and stability studies. The formulated sustained release tablet passed all tests required. The dissolution profile of prepared tablets showed sustained release of drug up to 11 hours compared to the reference tablet formulation PROLOMET XI 100. Drug release data were then fitted in to release kinetic models such as zero order kinetic, first order kinetic, Higuchi model and Korsmeyer-Peppas model to study the release pattern of drug from each formulation. The prepared sustained release tablet formulation was compared with marketed formulation (reference formulation) for drug release study and factor f1 (difference factor) and f2 (similarity factor) were determined. From this study it can be concluded that as the concentration of Remusatia vivipara mucilage increases, there is decrease in the rate of drug release from the formulation. The best formulation was found to be F3 which consists of 20% Remusatia vivipara mucilage but did not give comparable drug release profile to the reference formulation with factor f1 69.4 % and f2 34.8%. But it can be said that Remusatia vivipara gum mucilage can be used in tablet formulation to give sustained release effect up to 10 hours or in combination with other natural gum mucilage it may enhance the release retardant effect of drug up to or more than 20 hrs. The release kinetic study showed that the prepared sustained release tablet formulation shows anomalous (non-fickian) diffusion pattern and follows both diffusion controlled and swelling controlled mechanisms for drug release.

Bioequivalence of a Generic Nateglinide Formulation in Healthy Chinese Volunteers under Fasting and Fed Conditions: A Randomized, Open-Label, Double-Cycle, Double-Crossover Study

<b><i>Introduction:</i></b> Nateglinide or <i>N</i>-(trans-4-isopropylcyclohexyl-1-carbonyl)-D-phenylalanine is a drug with a rapid hypoglycemic effect that is mainly used in the treatment of type 2 diabetes. Very few studies have assessed bioequivalence based on feeding status. This study aimed to assess the pharmacokinetic bioequivalence and safety of nateglinide-containing tablets (0.12 g) in healthy Chinese volunteers under fasting and fed conditions. <b><i>Methods:</i></b> The studies were performed in 2017–2018 in the Phase I Clinical Trial Ward of the Affiliated Hospital of Liaoning University of Traditional Chinese Medicine, China. Eligible Chinese volunteers received a single 0.12-g dose of the test or reference formulation, followed by a 7-day washout period and administration of the alternate formulation. Blood samples were collected at various time intervals, and plasma nateglinide concentrations were analyzed by liquid chromatography-tandem mass spectrometry. Then, the adverse events, laboratory test results, vital signs, and physical exam findings were compared between the 2 groups. <b><i>Results:</i></b> The ratios of the geometric means of C_max, AUC_0-t, and AUC_0-inf of the tested to reference preparations under fasting conditions were 105.03% (90% confidence interval [CI]: 99.53–110.83%), 104.02% (90% CI: 101.37–106.74%), and 104.04% (90% CI: 101.38–106.77%), respectively. The same ratios under fed conditions were 96.55% (90% CI: 85.80–108.65%), 103.08% (90% CI: 100.07–106.18%), and 103.07% (90% CI: 100.21–106.01%), respectively. The 90% CI values for C_max, AUC_0-t, and AUC_0-inf fell within the accepted range of bioequivalence (80.00–125.0%). Common adverse events included hypoglycemia, heart rate increase, palpitation, sweating, dizziness, and diarrhea. <b><i>Conclusions:</i></b> The test formulation (0.12 g) met the CFDA’s regulatory definition for bioequivalence to the reference formulation. Both formulations were well tolerated by healthy Chinese subjects. <b><i>Trial Registration:</i></b> This trial has been registered in the Chinese Clinical trial registry (ChiCTR2000030694), March 10, 2020.

Bioavailability and Bioequivalence of Two Oral Single Dose of Ibuprofen 400 mg to Healthy Volunteers

Objective: The objective of the two pharmacokinetic studies reported here was to compare the relative bio availability and bio equivalence of an ibuprofen 400 mg tablet from National Company (SDI) as a test with a reference formulation. Study Design: Evaluation of two open, randomized, cross-over studies, one single dose in healthy male volunteers. Methods: 20 healthy volunteers were randomized in a cross-over design to single dose of Profedin 400 mg produced from National Company, ibuprofen formulation, as a test and a reference formulation produced from Pharmacia & Upjohn, Ibuprofen 400 mg. Ibuprofen and standard of ibuprofen were analyzed by utilizing HPLC, the sample extracted from 0.5ml of plasma with an organic solution of isooctane and 2-propanol. The mobile phase consisted of 44% acetonitrile and 0.1% phosphoric acid. The flow rate was 1 ml/min. The analytical column was a C-18, 5um packing size. Detection of Ibuprofen and the internal standard occurred by UV absorbance at wavelength of 220 nm. Results: A single-dose study demonstrated that the bio availability of ibuprofen for both formulations was not significantly different. In addition, mean plasma levels of ibuprofen predictive of clinical efficacy were achieved within 1.5- 2.0 hours and the elimination of ibuprofen tablets is virtually complete in 12 hours after the single dose. The serum half-life is 1.8 to 2.0 hours. The Cmax, Tmax, Kelemin.0.5 were calculated for the test and reference. They were not significantly different. Conclusions: Blood levels predicted that the present slow-release formulation of ibuprofen should offer reliable day and night control of pain and fever and is associated with a favorable safety profile.

Comparative Study on Pharmacokinetics of Four Long-Acting Injectable Formulations of Enrofloxacin in Pigs

A comparative study on pharmacokinetics of four long-acting enrofloxacin injectable formulations was investigated in 36 healthy pigs after intramuscular injection according to the recommended single dose @ 2.5 mg/kg body weight. The drug concentrations in the plasma were computed using high-performance liquid chromatography (HPLC) with fluorescence detection. WinNonLin5.2.1 software was used to analyze the experimental data and compared it under one-way ANOVA using SPSS software with a 95% confidence interval (CI). The main pharmacokinetic parameters, that is, the maximum plasma concentrations (Cmax), the time to maximum concentration (Tmax), area under the time curve concentration (AUCall) and Terminal half-life (T1/2) were 733.84 ± 129.87, 917.00 ± 240.13, 694.84 ± 163.49, 621.98 ± 227.25 ng/ml, 2.19 ± 0.0.66, 1.50 ± 0.37, 2.89 ± 0.24, 0.34 ± 0.13 h, 7754.43 ± 2887.16, 8084.11 ± 1543.98, 7369.42 ± 2334.99, 4194.10 ± 1186.62 ng h/ml, 10.48 ± 2.72, 10.37 ± 2.38, 10.20 ± 2.81, and 10.61 ± 0.86 h for 10% enrofloxacin (Alkali), 20% enrofloxacin (Acidic), Yangkang and control drug Nuokang® respectively. There were significant differences among Cmax, Tmax, and AUCall of three formulations compare with that of the reference formulation. No significant differences were observed among the T1/2 for tested formulations compare with the reference formulation. The pharmacokinetic parameters showed that the tested formulations were somewhat better compared to the reference one. The calculated PK/PD indices were effective for bacteria such as Actinobacillus pleuropneumoniae and Pasteurella multocida with values higher than the cut-off points (Cmax/MIC90≥10–12 and AUC/MIC90 ≥ 125). However, they were not effective against bacteria like Haemophilus parasuis, Streptococcus suis, E. coli, and Bordetella bronchiseptica where lower values were obtained.

The nodal-based floating frame of reference formulation with modal reduction

In a recent paper of the authors, a novel nodal-based floating frame of reference formulation (FFRF) for solid finite elements has been proposed. The nodal-based approach bypasses the unhandy inertia shape integrals ab initio, i.e. they neither arise in the derivation nor in the final equations of motion, leading to a surprisingly simple derivation and computer implementation without a lumped mass approximation, which is conventionally employed within commercial multibody codes. However, the nodal-based FFRF has so far been presented without modal reduction, which is usually required for efficient simulations. Hence, the aim of this follow-up paper is to bring the nodal-based FFRF into a suitable form, which allows the incorporation of modal reduction techniques to reduce the overall system size down to the number of modes included in the reduction basis, which further reduces the computational complexity significantly. Moreover, this exhibits a way to calculate the so-called FFRF invariants, which are constant “ingredients” required to set up the FFRF mass matrix and quadratic velocity vector, without integrals and without a lumped mass approximation.

Consistent and Inertia-Shape-Integral-Free Invariants of the Floating Frame of Reference Formulation

The conventional continuum-mechanics-based floating frame of reference formulation involves unhandy so-called inertia-shape-integrals in the equations of motion, which is why, commercial multibody software codes resort to a lumped mass approximation to avoid the evaluation of these integrals in their computer implementations. This paper recaps the conventional continuum mechanics floating frame of reference formulation and addresses its drawbacks by summarizing recent developments of the so-called nodal-based floating frame of reference formulation, which avoids inertia shape integrals ab initio, does not rely on a lumped mass approximation, and exhibits a way to calculate the so-called invariants, which are constant “ingredients” required to set up the equations of motion, in a consistent way.