Flow properties of single origin chocolates: Effect of product formulation and particle size.

The objective of this research was to evaluate changes in flow behavior of chocolate during chocolate grinding using a stone grinder as affected by chocolate formulation. Three different types of chocolates were evaluated. Two chocolates without milk added (70% chocolate) and two chocolates with milk added and with different amounts of cocoa nibs (30% chocolate and 14% chocolate) were tested. For the 70% chocolates, nibs of two different origins were used; therefore, a total of four samples were evaluated. Chocolates were processed in a stone grinder, and samples were taken as a function of grinding time. For each timepoint, the flow behavior of the samples was measured using a rotational rheometer and fitted to the Casson model. Particle size was measured using a laser scattering instrument. Results showed that yield stress increased linearly while the Casson plastic viscosity decreased exponentially with grinding time (smaller particles). Particle size distribution of the chocolates showed a prominent bimodal distribution for short grinding times (∼9 h) with small (∼15 µm) and large (∼100 µm) particles; with longer grinding time, the population of larger particles decreased. Yield stress values were higher for the 70% chocolate, but they were not very different between the two milk chocolates tested. The Casson plastic viscosity was greatest for the 70% chocolate, followed by the 30% chocolate. The 14% chocolate had the lowest Casson plastic viscosity. Changes of Casson plastic viscosity with particle size were more evident for the dark chocolates compared to the milk ones. These results are helpful to small chocolate producers who need better understanding of how the formulation and grinding of chocolate affect its flow behavior, which will ultimately affect chocolate handling during production.

Perfluorooctanoic acid (PFOA) removal by flotation with cationic surfactants.

Perfluorooctanoic acid (PFOA) was separated and recovered using a foam flotation process aided by cationic surfactants. The PFOA removal efficiency was in the following decreasing order: OTAB (C8TAB) > DTAB (C10TAB) > CTAB (C16TAB) > TBAB, which indicates that cationic surfactants with an alkyl chain that had a similar length to that of PFOA had higher affinities to PFOA. PFOA removal slightly decreased with increasing ionic strength of the surfactant but did not change with the pH. PFOA could be completely removed in 20 min with 1.25 mM of OTAB in actual wastewater. The energy yield value of foam flotation with a cationic surfactant was much higher than those of other methods, which means that using foam flotation with a cationic surfactant as the collector is a simple, fast, and energy-efficient method to separate and recover PFOA from dilute water solutions.

Experimental Study about Appropriate Time for Compounding Equal Volume Mixture of Heparinoid Oil-Based Cream and Steroid Cream Using Planetary Centrifugal Mixer / 医薬品情報学

Objective: The measurement of compounded topical medications’ uniformity is an important component of quality assessment. This study was aimed to evaluate appropriate mixing time for external preparations using a planetary centrifugal mixer.Methods: In order to evaluate the product uniformity of mixtures of five different steroid cream (Antebate®, Myser®, Methaderm®, Lidomex®, and Locoid®) with three different heparinoid oil-based cream (Hirudoid®, “Nichi-Iko” cream and “Nipro” cream), steroid cream and heparinoid oil-based cream (5 g each) were added into a 13 mL container and mixed using the mixer (NanKo Rentaro NRE-120®, THINKY) at rotation speed of 800 rpm and revolution speed of 2,000 rpm. We sampled 0.1 g of the mixture from three spots (top, middle, and bottom portions) of the container then, measured the steroid content by HPLC method. The yield value points of each cream and heparinoid oil-based cream were also measured by spread meter.Results: Our results showed that when the coefficient of variation (CV) is less than 15.2 %, a mixing time of at least 120 s was required to achieve proper mixing to obtain the permissible limit of steroid cream and heparinoid oil-based cream. Also the greater difference of the yield value between steroid cream and heparinoid oil-based cream tended to be mixed easier.Conclusions: These results suggest that the spread ability of steroid cream and heparinoid oil-based cream affects the mixing efficiency of a planetary centrifugal mixer.

[Optimum Volume of Water Needed for the Paste State of Pediatric Powders: Considerations Based on Yield Values and Applications to Generic Medicine].

To clarify the volume of water required to paste pediatric powders, we herein established a standard for the powder paste state by measuring yield values when water was added to powders. The powders used in the present study were selected from 8 types including original and generic drugs. Tipepidine hibenzate is prescribed in the pediatric field in combination with ambroxol hydrochloride and l-carbocysteine. The volumes of water needed to achieve the paste state of ambroxol hydrochloride between the original and generic drugs were similar. However, the volumes of water needed for l-carbocysteine markedly differed between the original and generic drugs due to differences in their additives. The spreadability of the mixture when water was added to the powders was evaluated using a spread meter. Among the powders tested in the present study, the yield value to achieve a paste state with the addition of water was approximately 1000 dyne/cm2. The optimum volume of water estimated from this yield value using the linear proportional relationship for the amount of powder may be applied to the mixture of each pediatric power for dosage/body weight.