Vial Temperature Research Articles

Determination of multiple residual solvents in ibandronate sodium using headspace-gas chromatography

Ibandronate sodium, a third-generation diphosphate drug used worldwide to treat osteoporosis, has the advantages of convenient use, low toxicity, and significant therapeutic effects. However, the residual organic solvents in the synthesis process of sodium ibandronate not only have a negative impact on the efficacy of the drug, but also lead to a decrease in drug stability. Moreover, if the residual amounts of these solvents exceed safety standards, they may pose serious threats to human health. This study successfully established a convenient and efficient method based on headspace-gas chromatography (HS-GC) for the simultaneous determination of five residual solvents (methanol, acetone, benzene, toluene, 1-pentanol) in the raw materials of ibandronate sodium. The results indicated that satisfactory analytical performance can be achieved by using DB-624 capillary column (30 m×0.32 mm×1.8 μm) and a flame ionization detector in conjunction with headspace autosampling and a temperature program. The specific operating conditions included an initial temperature of 40 ℃, with a hold of 2 min, followed by a temperature ramp first to 200 ℃ at a rate of 5 ℃/min and then to 240 ℃ at a rate of 20 ℃/min, with a hold of 5 min. Nitrogen with a flow rate of 1 mL/min and split ratio of 14∶1 was used as the carrier gas. The headspace vial temperature was maintained at 80 ℃, and the sample equilibration time was 20 min. Under the established analytical conditions, good linear relationships were obtained between the mass concentrations of methanol (72-216 μg/mL), acetone (120-360 μg/mL), benzene (0.048-0.144 μg/mL), toluene (21.36-64.08 μg/mL), and 1-pentanol (120-360 μg/mL) and their corresponding peak areas, with correlation coefficients (r) greater than 0.990. The limits of detection for these solvents were 2.88, 0.011, 0.90, 0.24, and 0.024 ng/mL, respectively, with limits of quantification of 11.5, 0.043, 3.6, 0.96, and 0.096 ng/mL, respectively. Furthermore, the recoveries of these solvents ranged from 86.3% to 101.9%, with relative standard deviations (RSDs, n=3) of less than 2.49%. The proposed method is simple, accurate, reliable, and suitable for the rapid and simultaneous determination of five residual solvents in the raw materials of ibandronate sodium. This study has important practical significance in improving drug safety and ensuring public health.

Rapid Determination of Five Residual Solvents in Ursodeoxycholic Acid Raw Materials

The chromatographic conditions were optimized using headspace gas chromatography, and a simple and rapid method was established for the simultaneous determination of five residual solvents in ursodeoxycholic acid raw materials. The corresponding quality standards were revised. The research results demonstrate that by utilizing a capillary column with a stationary phase consisting of 5% phenyl-95% dimethylpolysiloxane (HP-5, 30 m × 0.32 mm, film thickness 1.0 µm) and a flame ionization detector in conjunction with a headspace injection system and a programmed temperature ramping method, satisfactory analytical results can be achieved. The specific operating conditions are as follows: an initial column temperature of 45 °C, followed by a column temperature increase at a rate of 5 °C per minute up to 60 °C, then a further increase at a rate of 10 °C per minute up to 100 °C, and finally a rapid increase at a rate of 40 °C per minute up to 200 °C, where it is held for 10 min. Nitrogen is employed as the carrier gas at a flow rate of 1 mL/min with a split ratio of 14:1. The headspace vial temperature is maintained at 100 °C, with a sample equilibration time of 45 min. The concentration of methanol ranged from 0.06 mg/mL to 0.3 mg/mL, and the concentrations of acetone, tert-butanol, ethyl acetate, and triethylamine showed a good linear relationship with the peak area within the range of 0.1 mg/mL to 0.5 mg/mL (r = 0.999); The quantitation limits for methanol, acetone, tert-butanol, ethyl acetate, and triethylamine were 4.2, 0.9, 1.5, 1, and 0.1 μg/mL, respectively, with detection limits of 1.2, 0.25, 0.025, 0.3, and 0.025 μg/mL, respectively. The recovery rates of each solvent ranged from 92.9% to 106.0%, with RSD% (n = 9) less than 3.8%; the method exhibited good repeatability, with RSD% (n = 6) less than 2.5%. Furthermore, the robustness is good. The established method is simple, accurate, specific, and highly sensitive, and can be used for the simultaneous and rapid determination of five residual solvents in ursodeoxycholic acid raw materials.

A Stability Indicating Reverse Phase High Performance Liquid Chromatography Method for Related Substances of Sofosbuvir in Tablet Dosage Form

Sofosbuvir is an antiviral drug that is used to treat hepatitis C. A present investigation deals with simple, sensitive, rapid, precise and accurate reverse phase high-performance chromatography (RP-HPLC) method developed and validated for related substances of sofosbuvir in tablet dosage form. The chromatographic separation was achieved on a Kromasil 100 C18 (250 × 4.6 mm, 5 μ) column. A sofosbuvir and its impurities were extracted by composed mixture of Mobile Phase A: buffer solution: acetonitrile (97.5:2.5% v/v) and Mobile Phase B: acetonitrile, isopropyl alcohol, methanol and purified water (60:20:10:10 % v/v/v/v) using with flow rate was 1-mL/min, column temperature was 25°C, injection volume was 10 μL, Vial thermostat temperature was 10°C. The UV detection was carried out at 263 nm. The retention time of sofosbuvir, methyl ester and ethyl ester were 54.28, 36.31 and 43.77, respectively. The method shows linearity with correlation coefficient of sofosbuvir and its impurity was 0.999 over the 0.5–7.5 ppm range. The average recovery was found to be 90.2–113.9%. The LoD and LoQ for sofosbuvir and its impurities were found to be 0.1 and 0.5 μg/mL, respectively. The method was validated as per ICH guidelines. The developed method was precise, accurate, novel and detectable towards sofosbuvir and its impurity. This method is efficient in separating the sofosbuvir and its impurity. Hence, the proposed method can be utilized for the determination of related substances in routine analysis in quality control department of pharmaceutical Industry.

Evaluation of a PAT-based in-line control system for a continuous spin freeze-drying process

Continuous spin freeze-drying provides a range of opportunities regarding the implementation of several in-line process analytical technologies (PAT) to control and optimize the freeze-drying process at the individual vial level. In this work, two methods were developed to (1) control the freezing phase by separately controlling the cooling and freezing rate and (2) control the drying phase by controlling the vial temperature (and hence the product temperature) to setpoint values and monitoring the residual moisture content. During the freezing phase, the vial temperature closely followed the decreasing setpoint temperature during the cooling phases, and the crystallization phase was reproducibly controlled by regulating the freezing rate. During both primary and secondary drying, vial temperature could be maintained on the setpoint temperature which resulted in an elegant cake structure after every run. By being able to accurately control the freezing rate and the vial temperature, a homogeneous drying time (SD = 0.07–0.09 h) between replicates was obtained. Applying a higher freezing rate significantly increased primary drying time. On the other hand, fast freezing rates increased the desorption rate. Finally, the residual moisture of the freeze-dried formulation could be monitored in-line with a high accuracy providing insight on the required length of the secondary drying phase.

Development and Application of a Mechanistic Cooling and Freezing Model of the Spin Freezing Step within the Framework of Continuous Freeze-Drying.

During the spin freezing step of a recently developed continuous spin freeze-drying technology, glass vials are rapidly spun along their longitudinal axis. The aqueous drug formulation subsequently spreads over the inner vial wall, while a cold gas flow is used for cooling and freezing the product. In this work, a mechanistic model was developed describing the energy transfer during each phase of spin freezing in order to predict the vial and product temperature change over time. The uncertainty in the model input parameters was included via uncertainty analysis, while global sensitivity analysis was used to assign the uncertainty in the model output to the different sources of uncertainty in the model input. The model was verified, and the prediction interval corresponded to the vial temperature profiles obtained from experimental data, within the limits of the uncertainty interval. The uncertainty in the model prediction was mainly explained (>96% of uncertainty) by the uncertainty in the heat transfer coefficient, the gas temperature measurement, and the equilibrium temperature. The developed model was also applied in order to set and control a desired vial temperature profile during spin freezing. Applying this model in-line to a continuous freeze-drying process may alleviate some of the disadvantages related to batch freeze-drying, where control over the freezing step is generally poor.

Validation of Modifications to the Soleris®E. coli Method for Detection and Threshold Determination of Escherichia coli in Select Foods: Level 3 Modification to AOAC Performance Tested MethodSM 101101.

Soleris®E. coli is an automated, growth-based method for detection and semi-quantitative determination of Escherichia coli in foods. The method can be used in dilute-to-specification (threshold) or presence/absence modes. The objective of the study was to validate four modifications to the method: (1) a change in the vial detection window plug composition from agar to agarose to improve plug consistency and robustness, (2) a change in pre-enrichment incubation time for presence/absence testing from 6 h to 18-24 h, (3) a change in vial incubation temperature from 44.5 to 43.5°C, and (4) incorporation of a simple direct-from-vial confirmation test as an alternative to traditional procedures. Elements of the study included inclusivity/exclusivity testing, matrix testing in comparison to the ISO 7251:2005 reference method, reagent stability/lot-to-lot consistency testing, and an independent laboratory study. In inclusivity testing, all 55 Escherichia coli strains tested produced positive results. In exclusivity testing, 30 of 31 strains of other bacterial species produced negative results, the sole exception being a strain of Enterobacter cloacae. In internal and independent laboratory matrix testing of mozzarella cheese, condensed milk, pasteurized liquid egg, and frozen green beans, results showed no significant differences in performance of the Soleris and reference methods with two exceptions, one in which the Soleris method produced more positive results, and one in which the reference method produced more positive results. Performance characteristics of the modified Soleris E. coli method are consistent with those of the original validated method. The Soleris E. coli method offers improvements in ease of use and reagent robustness.

Impact of chamber wall temperature on energy transfer during freeze-drying.

Minimization of radiation coming from the chamber wall during lyophilization has the potential to reduce the edge-vial-effect. The edge-vial-effect is a phenomenon in which vials positioned at the shelf edges and corners tend to run warmer compared to center vials. A higher product temperature may result in product collapse in these vials. Consequently, more conservative and time-consuming freeze-drying cycles with lower shelf temperatures and pressures are chosen to ensure a product temperature below the collapse temperature in all vials. The edge-vial-effect is of even higher impact in small batches, where the ratio of corner and edge to center vials is higher compared to large scale manufacturing. The chamber wall is often discussed as the primary source of radiation impacting corner and edge vials. A radiation cage was set at different low temperatures to determine the impact of chamber wall temperatures below 0°C on product temperature. At the end of primary drying, product temperature of corner vials could be reduced by 6°C through the radiation cage but primary drying was elongated. Compared to vials in a tray, the chamber wall temperature had less impact on vials nested in a rack system due to a shielding effect of the rack itself. Corner and center vials ran more homogeneous with radiation cage since the edge and corner vials were slowed down. The difference in primary drying time between corner and center vials in the tray could be significantly reduced by 18% by means of 7h when the radiation cage was controlled at product temperature and combined with a higher shelf temperature. In summary, the radiation cage is a useful tool for a more homogeneous batch with the potential to reduce primary drying time. Nevertheless, the drying difference between corner and center vials could only be reduced and was not completely eliminated.

Multivariable control of ball-milled reactive material composition and structure

In reactive bimetallic compounds such as Ni–Al multilayers, desirable thermo-kinetic properties upon ignition require simultaneously controlled geometric microstructure and material composition. This article establishes fundamental dynamical models of plastic deformation and material diffusion in ball milling processing of particulates from Ni and Al powders, for the purpose of designing and implementing feedback control strategies for process control. The role of heat dissipation from plastic yield and friction slip in affecting compressibility and diffusivity of the material is elucidated. The different sensitivity of compressibility and diffusivity to thermal power is exploited by introducing multivariable control of both bilayer thickness and penetration depth simultaneously, using a real-time computational model as an observer with adaptation informed by infrared measurements of external vial temperature. The proposed control scheme is tested on a laboratory low-energy ball milling system and demonstrated to effectively modulate power intensity and process duration to obtain the desired microstructure and material composition.

An Experimental-Based Approach to Construct the Process Design Space of a Freeze-Drying Process: An Effective Tool to Design an Optimum and Robust Freeze-Drying Process for Pharmaceuticals

The application of quality by design (QbD) is becoming an integral part of the formulation and process development for pharmaceutical products. An essential feature of the QbD philosophy is the design space. In this sense, a new approach to construct a process design space (PDS) for the primary drying section of a freeze-drying process is addressed in this paper. An effective customized design of experiments (DoE) is developed for freeze-drying experiments. The results obtained from the DoE are then used to construct the product-based PDS. The proposed product-based PDS construction approach has several advantages, including (1) eliminating assumptions on the heat transfer coefficient and dried product resistance, as it is constructed from experimental results specifically obtained from a given formulation, yielding more realistic and reliable results and (2) PDS construction based on a narrow range of product temperatures and considering the variations in product temperature and sublimation rate of vials across a shelf. This guarantees the effectiveness and robustness of the process and facilitates the process scale-up and transfer. The PDS developed herein was experimentally verified. The PDS predicted parameters were in excellent agreement with the experimentally obtained parameters.

Mixed Vapor Generation Device for delivery of homemade explosives vapor plumes

While there is a large body of research on the properties and detection of traditional military high explosives and propellant low explosives, there is a dearth of research on homemade explosive (HME) materials, though they are prevalent today. The safety of working with these materials in the laboratory is the greatest limiting factor preventing HME research. A vapor delivery tool, the Mixed Vapor Generation Device (MV-Gen), was designed to safely contain the individual solid or liquid components that often compose homemade explosives vapor plumes and deliver the mixed component vapors for instrumental sampling and analysis. Within the MV-Gen, each component is separated and only the vapors mix as they are carried through the device by flowing air. The resulting mixed vapor is representative of either mixed explosive material or bulk explosives. Component materials are held in up to four individual, removable vials with vapor concentrations controlled by vial orifice size, temperature, and diluent airflow. The total concentration can be adjusted by altering vial temperature via a thermal water jacket surrounding the entirety of the device, or by adjusting the flow rate of diluent air through the device. The MV-Gen was evaluated first with surrogate compounds, followed by two types of homemade explosives, to include a binary explosive mixture and a peroxide explosive. To evaluate the device, vapors were cold-trapped on an online sampling system and analyzed by gas chromatography/mass spectrometry. It was determined that the device yielded reproducible vapor concentrations of both single and mixed components, and the ratio of these vapors can be easily adjusted to mimic varying forms of homemade explosives.

Bimetallic diffusion modeling and temperature regulation during ball milling

This work establishes a computationally efficient model of temperature and diffusion dynamics in ball milled bimetallic Ni-Al particulates. Mechanical contact conditions between adjacent bimetallic domains and temperature fields generated upon impact define the diffusive fluxes through the domains' interfaces. The concentration distributions are studied via Green's function methods, by defining mirror images which reflect the boundary diffusive resistance conditions. Predictions of the model are validated against experimental open-loop scanning electron micrographs and X-ray diffraction spectra at steady-state. Dynamic models of diffusion saturation and internal temperature are developed for the design of closed-loop controller via simulation. This feedback controller is implemented on a laboratory device, equipped with infrared thermometry for external vial temperature measurement, as a self-tuning regulator. The controller adapts an efficiency parameter of the model that thus serves as a real-time observer for internal temperature and diffusion saturation, which are physically inaccessible during processing. Experimental open-loop results are employed to set thresholds of diffusion penetration to avoid early exothermic reaction during fabrication. By controlling the process duration, the regulation system successfully reproduces the material composition of the open-loop reference tests, to ensure desired thermodynamic properties of the ball milled products and safety of the operation.

An investigation on the mechanism and reaction sequence of scheelite-magnesium mixtures during mechanical milling

The mechanism of mechanically-induced self-propagating reaction (MSR) of scheelite with magnesium during reactive ball milling was investigated using in-situ monitoring of the vial temperature, X-ray diffraction analysis and field emission scanning electron microscopy. Temperature variations of the vial versus milling time curves showed unusual behaviors in comparison to the reported patterns in literature. It is found that the main reason for these exceptional temperature behaviors is sublimation-deposition of magnesium. X-ray diffraction patterns of milled scheelite-magnesium mixtures revealed the formation of intermediate phases during MSR. The sequence of scheelite-magnesium reaction appeared as CaWO4→ Ca3WO6 → Ca2MgWO6 → WO3-x → W. Atomic force microscopy showed that the final product contains nanosize particles that are smaller than 50nm.

Development of a Mini-Freeze Dryer for Material-Sparing Laboratory Processing with Representative Product Temperature History

The goal of the work described in this publication was to evaluate a new, small, material-sparing freeze dryer, denoted as the "mini-freeze dryer or mini-FD", capable of reproducing the product temperature history of larger freeze dryers, thereby facilitating scale-up. The mini-FD wall temperatures can be controlled to mimic loading procedures and dryer process characteristics of larger dryers. The mini-FD is equipped with a tunable diode laser absorption spectroscopy (TDLAS) water vapor mass flow monitor and with other advanced process analytical technology (PAT) sensors. Drying experiments were performed to demonstrate scalability to larger freeze dryers, including the determination of vial heat transfer coefficients, K v . Product temperature histories during K v runs were evaluated and compared with those obtained with a commercial laboratory-scale freeze dryer (LyoStar II) for sucrose and mannitol product formulations. When the mini-FD wall temperature was set at the LyoStar II band temperature (-20°C) to mimic lab dryer edge vials, edge vial drying in the mini-FD possessed an average K v within 5% of those obtained during drying in the LyoStar II. When the wall temperature of the mini-FD was set equal to the central vial product temperature, edge vials behaved as center vials, possessing a K v value within 5% of those measured in the LyoStar II. During both K v runs and complete product freeze drying runs, the temperature-time profiles for the average edge vials and central vial in the mini-FD agreed well with the average edge and average central vials of the LyoStar II.

Mechanochemical synthesis mechanism of Ti3AlC2 MAX phase from elemental powders of Ti, Al and C

In this study, the synthesis of Ti3AlC2 MAX phase in Ti–Al–C system was investigated by high-energy ball milling. To this aim, mixtures of Ti, Al and C with stoichiometric ratios were milled by a planetary ball mill for different milling times up to 10h. The structural evaluation of powder particles, after different milling times, was studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) equipped with energy-dispersive spectroscopy (EDS) and measurement of vial temperature. Thermodynamic investigations showed that direct reactions among elemental powders of titanium, aluminum, and carbon were strongly exothermic and the product phases were formed in a self-sustaining regime. The experimental result showed that after 10h milling the elemental powders reacted together through a rapid combustion reaction process resulting in the formation of Ti3AlC2 and TiC. It was proved that mechanically induced self-propagating reaction (MSR) is dominant mechanism.

Effectiveness of a web-based education program to improve vaccine storage conditions in primary care (Keep Cool): study protocol for a randomized controlled trial.

BackgroundImmunization programs are among the most effective public health strategies worldwide. Adequate vaccine storage is a prerequisite to assure the vaccines’ effectiveness and safety. In a questionnaire survey among a random sample of German primary care physicians, we discovered vaccine storage deficits: 16 % of physicians had experience with cold chain breaches either as an error or near error, 49 % did not keep a temperature log, and 21 % did not use a separate refrigerator for vaccine storage. In a recent feasibility study of 21 practice refrigerators, we showed that these were outside the target range 10.2 % of the total time with some single refrigerators being outside the target range as much as 66.3 % of the time. These cooling-chain deficits are consistent with the international medical literature, yet an effective, easy to disseminate, practice-centered intervention to improve storage conditions is lacking.Methods/designThis randomized intervention trial will be conducted in a random sample of primary care practices. Based on continuous temperature recordings over 7 days, all practices with readings outside the target range for vaccine storage (+2 °C to +8 °C) will be randomly allocated to a web-based education program or a waiting list control group. The practice physicians and their teams constitute the target population. Participants will be educated about best practices in vaccine storage and will receive a manual including storage checklists and templates for temperature documentation. In all practices, temperatures of the vaccine refrigerators will be monitored continuously using a data logger with a glycol probe as a surrogate for vaccine vial temperature. The effectiveness of the web-based education program will be determined after 6 months in terms of the proportion of refrigerators with vaccine vial temperatures within the target range (+2 °C to +8 °C) during 7-day temperature logging. Secondary outcome parameters include temperature monitoring, no critically low temperatures (≤ -0.5 °C), compliance with storage recommendations, knowledge of good vaccine storage conditions, and assignment of personnel as vaccine storage manager and backup.DiscussionKeep Cool will develop and evaluate a web-based education program to improve vaccine storage conditions in primary care and thereby ensure immunization safety and effectiveness.Trial registrationDRKS00006561 (date of registration: 20 February 2015)

Effectiveness of Alcohol Cosurfactants in Hydrate Antiagglomeration

Hydrates are crystalline inclusion compounds where hydrogen bonded water molecules form cages to trap small hydrocarbon and nonhydrocarbon molecules. Under high subcooling conditions, these crystals grow rapidly into large pieces and may cause enormous problems in transport and deepwater oil capture. One of the most effective methods to address gas hydrate problems is through the formation of small hydrate particles in the nanometer or micrometer range dispersed in the fluid phase. In this approach, special surfactants are required, which are called antiagglomerants (AAs). However, there are major limitations when salt is present in water and when volume ratio of water in fluid (i.e., watercut) is high. In this work, we investigate a wide range of alcohols as cosurfactants along with the rhamnolipid as AA in a multiple screening-tube rocking apparatus by monitoring the temperature of vials and morphology of mixtures. The results show medium-sized alcohols, such as isopropanol (IPA), are effective cosurfac...

Analysis of the decomposition gases from α and β-Cd(BH4)2 synthesized by temperature controlled mechanical milling

We present a comprehensive study on the controlled phase synthesis and thermal decomposition of Cd(BH2)4, a material for solid state hydrogen storage obtained via the metathesis reaction of LiBH4 with CdCl2. By adjusting the stochiometry of the reactants and controlling the mechanical milling vial temperature, we have isolated the tetragonal (P42mn) low temperature phase and the cubic (Pn3¯m) high temperature phase of the cadmium borohydride. Cd(BH2)4 has a low thermodynamic stability and decomposes with fast kinetic at 348K, when heated at 1Kmin−1 against a backpressure of 1bar H2. A semi-quantitative analysis reveals that the decomposition gases are composed of 1:1 H2+B2H6 and that only Cd remains as solid crystalline phase.

Head space voltammetry: A novel voltammetric method for volatile organics and a case study for phenol

Present paper describes the results of a novel method which combines the Head space (HS) preconcentration of the analyte on the electrode prior to the voltammetric analysis. Thereafter, the method was called HS-Voltammetry. The performance of the method was tested upon using an electroactive and volatile molecule, phenol molecule, which gives an oxidation peak at conventional electrodes. In this study, a glassy carbon electrode was modified with polypyrrole by electropolymerization and then, the electrode was placed over the solution in a sealed vial heated gently on a hotplate with a stirrer for phenol determination. By controlling the thickness of the polymeric coating and optimizing preconcentration parameters such as vial pH and temperature, stirring rate and exposure time, a very consistent (5.2% at 5.0×10−7M) fraction of the analyte can be extracted during a predetermined time. The oxidation peak current at 0.8V depended linearly on the phenol concentration over a wide range (3 orders of magnitude). The detection limit was estimated as 7.0×10−8M at 60°C (S/N=3) which is well below the limit set by the European Community for phenols in wastewaters (ca. 5×10−6M). The effect of other phenolic compounds was also examined and it was shown that head space preconcentration eliminated the interference of non-volatile phenolic acids studied. For volatile phenolic compounds, the selectivity can be maintained in cases when isolated peaks are obtained for each component. The proposed method has been applied successfully for the determination of phenol in artificial wastewater and recovery percentage was calculated as 93%.

Investigation of Freeze/Thaw-Related Quality Attributes of a Liquid Biopharmaceutical Formulation: The Role of Saccharide Excipients

Saccharides, including sucrose, trehalose, mannitol, and sorbitol, are commonly employed as stabilizers, cryoprotectants, and/or tonicity adjusters in protein formulations. During the thawing of a protein-containing formulated bulk drug substance conducted prior to a drug product (DP) filling operation, a white, crystalline precipitate was observed. In addition, upon thawing, vial breakage was observed for filled DP that had been previously frozen at -40 °C. To investigate the causes of both phenomena, the freeze/thaw behavior of the formulation components was studied. Multiple physical characterization techniques, including differential scanning calorimetry (DSC), electrical resistance measurements, thermomechanical analysis (TMA), and powder X-ray diffraction (PXRD), were utilized to characterize the formulations. The PXRD pattern of precipitate collected from thawed bulk was consistent with that of a mannitol control. An exothermic transition observed by DSC, a sharp increase in electrical resistance detected via resistivity measurements, and the onset of volumetric expansion of the frozen matrix evident in the TMA curve offer evidence that the frozen mannitol solution undergoes transitions at or near the vial breakage temperature (-22 to -23 °C) observed during warming. In addition, osmolality measurements taken from fractionated aliquots of frozen samples indicated that non-uniform concentration gradients contributed to precipitation of mannitol observed at larger scales. Small-scale laboratory experiments (i.e., 10-125 mL) failed to adequately predict behavior at larger scale (i.e., in 1 L and 2 L bottles). Upon linking the detrimental behavior to the freeze/thaw properties of the tonicity adjustor, mannitol, alternative saccharide excipients, including sorbitol, sucrose, and trehalose, were evaluated at isotonic concentrations over a temperature range of -80 to 25 °C using physical-chemical techniques and visual observation. Neither precipitation nor vial breakage was observed for the alternate saccharides. Recommendations for saccharide selection are provided based on storage conditions and scale considerations for liquid biopharmaceutical formulations. Saccharides, including sucrose, trehalose, mannitol, and sorbitol, are commonly employed as stabilizers, cryoprotectants and/or tonicity adjusters in protein formulations. During thawing of formulated bulk drug substance, a white, crystalline precipitate was observed. In addition, upon thawing, vial breakage was observed for filled drug product that had been previously frozen at -40 °C. To investigate the causes of both phenomena, multiple physical characterization techniques were utilized to characterize the formulations. The powder X-ray diffraction pattern of precipitate collected from thawed bulk was consistent with that of a mannitol control. Upon linking the detrimental behavior to the freeze/thaw properties of the tonicity adjustor, mannitol, alternative saccharide excipients, including sorbitol, sucrose, and trehalose, were evaluated at isotonic concentrations over a temperature range of -80 to 25 °C using physico-chemical techniques and visual observation. Neither precipitation nor vial breakage was observed for the alternate saccharides. Recommendations for saccharide selection are given based on storage conditions and scale considerations for liquid biopharmaceutical formulations.

The Effect of Preactivation Vial Temperature on the Acoustic Properties of DefinityTM

DefinityTM is a widely available clinically approved ultrasound contrast agent. The manufacturer’s instructions indicate that the refrigerated vial should be allowed to reach room temperature prior to its 45 s mechanical agitation activation process. Activation results in vial heating and it has been previously observed that “smaller” bubbles are formed later in this process (>10 s) when the vial temperature is elevated. The objective of this work was to examine the effects of preactivation vial temperature on the size distribution, frequency dependent attenuation (1.5–27 MHz) and nonlinear imaging performance of DefinityTM. Experiments were conducted with vials at refrigerator temperature (2°C), room temperature (22°C) or 37°C at the outset of the activation procedure. The size distributions were found to be strongly dependent on preactivation vial temperature and the attenuation results indicated considerable differences in the frequency response of the agent, most notably the appearance of a peak at 4 MHz for the 2°C case. Nonlinear imaging results performed using a 1–5 MHz transducer probe with a wall-less vessel phantom indicated that 2°C vials produced a signal enhancement 5.1 dB greater than for 22°C DefinityTM (p < 0.05). These results, therefore, indicate that not permitting the vial to reach room temperature has a considerable impact on the imaging performance of DefinityTM. Conversely, activating a cooled vial can provide a means by which to improve contrast enhancement when using low frequency clinical transducers.