Workload of Team Leaders and Team Members During a Simulated Sepsis Scenario.

OBJECTIVES: Crisis resource management principles dictate appropriate distribution of mental and/or physical workload so as not to overwhelm any one team member. Workload during pediatric emergencies is not well studied. The National Aeronautics and Space Administration-Task Load Index is a multidimensional tool designed to assess workload validated in multiple settings. Low workload is defined as less than 40, moderate 40-60, and greater than 60 signify high workloads. Our hypothesis is that workload among both team leaders and team members is moderate to high during a simulated pediatric sepsis scenario and that team leaders would have a higher workload than team members. DESIGN: Multicenter observational study. SETTING: Nine pediatric simulation centers (five United States, three Canada, and one United Kingdom). PATIENTS: Team leaders and team members during a 12-minute pediatric sepsis scenario. INTERVENTIONS: National Aeronautics and Space Administration-Task Load Index. MEASUREMENTS AND MAIN RESULTS: One hundred twenty-seven teams were recruited from nine sites. One hundred twenty-seven team leaders and 253 team members completed the National Aeronautics and Space Administration-Task Load Index. Team leader had significantly higher overall workload than team member (51 ± 11 vs 44 ± 13; p < 0.01). Team leader had higher workloads in all subcategories except in performance where the values were equal and in physical demand where team members were higher than team leaders (29 ± 22 vs 18 ± 16; p < 0.01). The highest category for each group was mental 73 ± 13 for team leader and 60 ± 20 for team member. For team leader, two categories, mental (73 ± 17) and effort (66 ± 16), were high workload, most domains for team member were moderate workload levels. CONCLUSIONS: Team leader and team member are under moderate workloads during a pediatric sepsis scenario with team leader under high workloads (> 60) in the mental demand and effort subscales. Team leader average significantly higher workloads. Consideration of decreasing team leader responsibilities may improve team workload distribution.

Improving quality through simulation; developing guidance to design simulation interventions following key events in healthcare.

Simulation educators are often requested to provide multidisciplinary and/or interprofessional simulation training in response to critical incidents. Current perspectives on patient safety focus on learning from failure, success and everyday variation. An international collaboration has led to the development of an accessible and practical framework to guide the implementation of appropriate simulation-based responses to clinical events, integrating quality improvement, simulation and patient safety methodologies to design appropriate and impactful responses. In this article, we describe a novel five-step approach to planning simulation-based interventions after any events that might prompt simulation-based learning in healthcare environments. This approach guides teams to identify pertinent events in healthcare, involve relevant stakeholders, agree on appropriate change interventions, elicit how simulation can contribute to them and share the learning without aggravating the second victim phenomenon. The framework is underpinned by Deming's System of Profound Knowledge, the Model for Improvement and translational simulation. It aligns with contemporary socio-technical models in healthcare, by emphasising the role of clinical teams in designing adaptation and change for improvement, as well as encouraging collaborations to enhance patient safety in healthcare. For teams to achieve this adaptive capacity that realises organisational goals of continuous learning and improvement requires the breaking down of historical silos through the creation of an infrastructure that formalises relationships between service delivery, safety management, quality improvement and education. This creates opportunities to learn by design, rather than chance, whilst striving to close gaps between work as imagined and work as done.

Development of the orpheus perfusion simulator for use in high-fidelity extracorporeal membrane oxygenation simulation.

Despite its life-sustaining potential, extracorporeal membrane oxygenation (ECMO) remains a complex treatment modality for which close teamwork is imperative with a high risk of adverse events leading to significant morbidity and mortality. The provision of adequate training and continuing education is key in mitigating these risks. Traditional training for ECMO has relied predominantly on didactic education and hands-on water drills. These methods may overemphasize cognitive skills while underemphasizing technical skills and completely ignoring team and human factor skills. These water drills are often static, lacking the time pressure, typical alarms, and a sense of urgency inherent to actual critical ECMO scenarios. Simulation-based training provides an opportunity for staff to develop and maintain technical proficiency in high-risk, infrequent events without fear of harming patients. In addition, it provides opportunities for interdisciplinary training and improved communication and teamwork among team members (1). Although simulation has become widely accepted for training of practitioners from many disciplines, there are currently, to our knowledge, no commercially available dedicated high-fidelity ECMO simulators. Our article describes the modification of the Orpheus Perfusion Simulator and its incorporation into a fully immersive, high-fidelity, point-of-care ECMO simulation model.

Stable-form screening: overcoming trace impurities that inhibit solution-mediated phase transformation to the stable polymorph of sulfamerazine.

Solution-mediated phase transformation (SMPT) has been used as a focused technique to rapidly identify the stable polymorph of a given substance. Despite ample precedence for acetonitrile being a good solvent for SMPT of sulfamerazine (SMZ), samples from specific lots of SMZ failed to convert from Form I to Form II after suspension for 2 weeks in acetonitrile. In these lots, an acetyl derivative of SMZ was identified and shown to impede transformation to the stable polymorph. The inhibitory effect of this impurity on polymorphic conversion was overcome with practical adjustments to experimental procedure, which hastened the kinetics of SMPT. The critical factors considered were (1) modifying the solvent to increase solubility, (2) minimizing the level of impurity in the slurries, (3) pre-treatment of the solid to quickly reach maximum supersaturation, and (4) temperatures that optimized kinetics as well as the free energy difference between enantiotropically related polymorphs.

Influence of crystal structure on the tableting properties of n-alkyl 4-hydroxybenzoate esters (parabens).

Certain crystallographic features, such as the existence of slip planes, can greatly facilitate the ability of crystals to deform plastically. An investigation of the relationship between the slip planes and the tableting performance of the crystals of methyl, ethyl, n-propyl, and n-butyl 4-hydroxybenzoate (parabens) was conducted. The absence of slip planes in methyl paraben crystal structure results in significantly poorer tableting performance than the other three parabens. While slip planes are present in the crystal structures of ethyl, propyl, and butyl parabens, they exhibited different plasticity as confirmed by crystal free volume analysis, crystal nano-indentation hardness, and Heckel analysis. Sieved fraction, 150-250 microm, of each paraben powder was compressed into tablets under different conditions. Tablet tensile strength, porosity, and Indices of tableting performance (ITP) were obtained. Under the same compaction pressure, tablet tensile strength was higher for crystals with higher plasticity. Tableting performance, assessed using the ITP, also improved with increasing crystal plasticity. The results confirm that high levels of plasticity, which can result from the presence of slip planes in crystal lattice, plays a critical role in the formation of strong and intact tablets by means of powder compaction.

A calorimetric investigation of thermodynamic and molecular mobility contributions to the physical stability of two pharmaceutical glasses.

The purpose of this work was to investigate the contribution of thermodynamics and mobility to the physical stability of two pharmaceutical glasses with similar glass transition temperatures (Tg), by comparing configurational thermodynamic quantities and molecular relaxation time constants (tau) at temperatures below Tg. Ritonavir and nifedipine were chosen as model glasses because they show excellent and poor physical stability, respectively. Although ritonavir and nifedipine have similar Tg values (50 and 46 degrees C, respectively), amorphous ritonavir is quite stable while nifedipine has been reported to crystallize at temperatures as low as 40 degrees C below Tg. Modulated temperature differential scanning calorimetry (MTDSC) was used to characterize both crystalline phases and freshly prepared glasses. The glasses were then annealed at Tg-Ta = 25 degrees C while monitoring the extent of relaxation and heat capacity change as a function of time via MTDSC. Configurational thermodynamic quantities (Gc, Hc, and Sc) and molecular relaxation time constants, tau, were calculated from the calorimetric data. Interestingly, the Gibbs free energy driving force for crystallization was nearly identical for the two compounds. The largest differences were found in the configurational entropy (Sc) values for the fresh glasses and in the Sc values over time. Configurational entropy values were approximately 50% higher for ritonavir. The tau values of freshly prepared glasses indicated that both materials had similar initial mobility at the annealing temperatures and the temperature dependence of tau was approximately Arrhenius, regardless of age. Although initial tau values were similar, the tau values after 3 days annealing were approximately sixfold greater for ritonavir. The relatively poor physical stability of nifedipine compared to ritonavir is attributed to both the lower entropic barrier to crystallization for fresh and annealed glass, and higher molecular mobility in aged glasses of nifedipine. These observations below Tg are consistent with the previous work on physical stability of amorphous pharmaceuticals performed above Tg.

Quantitation of crystalline and amorphous forms of anhydrous neotame using 13C CPMAS NMR spectroscopy.

Although most drugs are formulated in the crystalline state, amorphous or other crystalline forms are often generated during the formulation process. The presence of other forms can dramatically affect the physical and chemical stability of the drug. The identification and quantitation of different forms of a drug is a significant analytical challenge, especially in a formulated product. The ability of solid-state 13C NMR spectroscopy with cross polarization (CP) and magic-angle spinning (MAS) to quantify the amounts of three of the multiple crystalline and amorphous forms of the artificial sweetener neotame is described. It was possible to quantify, in a mixture of two anhydrous polymorphic forms of neotame, the amount of each polymorph within 1-2%. In mixtures of amorphous and crystalline forms of neotame, the amorphous content could be determined within 5%. It was found that the crystalline standards that were used to prepare the mixtures were not pure crystalline forms, but rather a mixture of crystalline and amorphous forms. The effect of amorphous content in the crystalline standards on the overall quantitation of the two crystalline polymorphic forms is discussed. The importance of differences in relaxation parameters and CP efficiencies on quantifying mixtures of different forms using solid-state NMR spectroscopy is also addressed.

Improving cardiopulmonary resuscitation with a CPR feedback device and refresher simulations (CPR CARES Study): a randomized clinical trial.

IMPORTANCE: The quality of cardiopulmonary resuscitation (CPR) affects hemodynamics, survival, and neurological outcomes following pediatric cardiopulmonary arrest (CPA). Most health care professionals fail to perform CPR within established American Heart Association guidelines. OBJECTIVE: To determine whether "just-in-time" (JIT) CPR training with visual feedback (VisF) before CPA or real-time VisF during CPA improves the quality of chest compressions (CCs) during simulated CPA. DESIGN, SETTING, AND PARTICIPANTS: Prospective, randomized, 2 × 2 factorial-design trial with explicit methods (July 1, 2012, to April 15, 2014) at 10 International Network for Simulation-Based Pediatric Innovation, Research, & Education (INSPIRE) institutions running a standardized simulated CPA scenario, including 324 CPR-certified health care professionals assigned to 3-person resuscitation teams (108 teams). INTERVENTIONS: Each team was randomized to 1 of 4 permutations, including JIT training vs no JIT training before CPA and real-time VisF vs no real-time VisF during simulated CPA. MAIN OUTCOMES AND MEASURES: The proportion of CCs with depth exceeding 50 mm, the proportion of CPR time with a CC rate of 100 to 120 per minute, and CC fraction (percentage CPR time) during simulated CPA. RESULTS: The quality of CPR was poor in the control group, with 12.7% (95% CI, 5.2%-20.1%) mean depth compliance and 27.1% (95% CI, 14.2%-40.1%) mean rate compliance. JIT training compared with no JIT training improved depth compliance by 19.9% (95% CI, 11.1%-28.7%; P < .001) and rate compliance by 12.0% (95% CI, 0.8%-23.2%; P = .037). Visual feedback compared with no VisF improved depth compliance by 15.4% (95% CI, 6.6%-24.2%; P = .001) and rate compliance by 40.1% (95% CI, 28.8%-51.3%; P < .001). Neither intervention had a statistically significant effect on CC fraction, which was excellent (>89.0%) in all groups. Combining both interventions showed the highest compliance with American Heart Association guidelines but was not significantly better than either intervention in isolation. CONCLUSIONS AND RELEVANCE: The quality of CPR provided by health care professionals is poor. Using novel and practical technology, JIT training before CPA or real-time VisF during CPA, alone or in combination, improves compliance with American Heart Association guidelines for CPR that are associated with better outcomes. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT02075450.

Racemic species of sodium ibuprofen: characterization and polymorphic relationships.

Racemic and homochiral sodium ibuprofen were characterized by thermal analysis and powder X-ray diffractometry. The melting point phase diagram was constructed and thermodynamic calculation was performed. In contrast to racemic ibuprofen, which is a racemic compound, racemic sodium ibuprofen forms both a racemic conglomerate (termed the gamma-form) as well as two polymorphic racemic compounds, alpha and beta, which are less stable monotropes. From the supercooled liquid, alpha and beta crystallized along with the original gamma-form. Forms alpha and beta are "enantiotropically related" with a transition temperature between 75 degrees and 113 degrees C, but can be considered to be metastable monotropes of the racemic conglomerate, the stable gamma-form.

Solid-state properties of warfarin sodium 2-propanol solvate.

The goal of the present work was to understand the effect of relative humidity (RH) and temperature on the molecular structure, crystal structure, and physical properties of warfarin sodium 2-propanol solvate (W). After previous determination of the crystal structure of W, which corresponds to a 1:1 2-propanol solvate, the present work shows that W has a critical RH (60% < RH(0) < or = 68%), below which minimal uptake of water occurs, due to surface adsorption, but above which gradual and continuous uptake of water occurs, due to deliquescence. Deliquescence begins at the surface and proceeds inward into the bulk of the crystal. Single crystal X-ray diffractometry indicates no change in the crystal and molecular structure of W during the initial stages of deliquescence. Studies of the unit cell and volume computations of W show that water can neither find space to enter the crystal lattice, nor can replace 2-propanol. Thus, water does not exchange with 2-propanol within the lattice, contrary to previous reports. Storage of single crystals of W at 120 degrees C for 23 h produces shrinkage cracks along the needle (b) axis, which are interpreted as a reduction in d-spacing of the 00l planes. Thus, under thermal stress, W crystals undergo amorphization with concurrent loss of 2-propanol, which may proceed via an intermediate crystalline phase. The phase changes of W, which depend on RH and temperature, are explained at the molecular level.

Dehydration kinetics of piroxicam monohydrate and relationship to lattice energy and structure.

The dehydration kinetics of piroxicam monohydrate (PM) is analyzed by both model-free and model-fitting approaches. The conventional model-fitting approach assuming a fixed mechanism throughout the reaction is found to be too simplistic. The model-free approach allows for a change of mechanism and activation energy, Ea, during the course of a reaction and is therefore more realistic. The complexity of the dehydration of PM is illustrated by the dependence of Ea on both the heating conditions, isothermal or nonisothermal, and on the fraction of conversion, alpha (0 < or = alpha < or = 1). Under both isothermal and nonisothermal conditions, Ea increases with alpha for 0 < or = alpha < or = 0.25, followed by an approximately constant value of Ea during further dehydration. In the constant-Ea region, isothermal dehydration follows the two-dimensional phase boundary model (R2), whereas nonisothermal dehydration follows a mechanism intermediate between two- and three-dimensional diffusion that cannot be described by any of the common models. Structural studies suggest that the complex hydrogen-bond pattern in PM is responsible for the observed dehydration behavior. Ab initio calculations provide an explanation for the changes in the molecular and crystal structures accompanying the reversible change in hydration state between anhydrous piroxicam Form I and PM. This work also demonstrates the utility of model-free analysis in describing complex dehydration kinetics.

Conformational flexibility and hydrogen-bonding patterns of the neotame molecule in its various solid forms.

The conformational flexibility and the molecular packing patterns of the neotame molecule in its various crystal forms, including neotame monohydrate, methanol solvate, ethanol solvate, benzene solvate, and anhydrate polymorph G, are analyzed in this work. The Cerius2 molecular modeling program with the Dreiding 2.21 force field was employed to calculate the most stable conformations of neotame molecules in the gaseous state and to analyze the conformations of the neotame molecule in its various crystal forms. Using graph set analysis, the hydrogen bond patterns of these crystal forms were compared. The neotame molecule takes different conformations in its crystal forms and in the free gaseous state. Cerius2 found 10 conformers with lower conformational energies than those in the actual crystal structures, which represent an energetic compromise. The relatively large differences between the energies of the conformers indicate the necessity for rewriting or customizing the force field for neotame. The hydrogen bonding patterns of the neotame methanol and ethanol solvates are identical, but different from those of the other three forms, which also differ from each other. The neotame molecule in its various crystal forms takes different conformations that differ from those in the gaseous state because of the influence of crystal packing. The intramolecular ring, S5, is present in all the crystal forms. The following hydrogen bonding patterns occur in some of the crystal forms: diad, D; intramolecular rings, S(6) and S(7); chains, C(5) and C(6); and an intermolecular ring, R2(2)(12).

Physical stability of amorphous pharmaceuticals: Importance of configurational thermodynamic quantities and molecular mobility.

This work relates the thermodynamic quantities (Gc, Hc, and Sc) and the molecular mobility values (1/tau) of five structurally diverse amorphous compounds to their crystallization behavior. The model compounds included: ritonavir, ABT-229, fenofibrate, sucrose, and acetaminophen. Modulated temperature DSC was used to measure the heat capacities as a function of temperature for the amorphous and crystalline phases of each compound. Knowledge of the heat capacities and fusion data allowed calculation of the configurational thermodynamic quantities and the Kauzmann temperatures (T(K)) using established relationships. The molecular relaxation time constants (tau) were then calculated from the Vogel-Tammann-Fulcher representation of the Adam-Gibbs model. Amorphous samples were heated at 1 K/min and a reduced crystallization temperature, defined as (Tc - Tg)/(Tm-Tg), was used to compare crystallization tendencies. Crystallization was observed for all compounds except ritonavir. The configurational free energy values (Gc) show that thermodynamic driving forces for crystallization follow the order: ritonavir > acetaminophen approximately fenofibrate > sucrose > ABT-229. The entropic barrier to crystallization, which is inversely related to the probability that the molecules are in the proper orientation, followed the order: ritonavir > fenofibrate > ABT-229 > acetaminophen approximately sucrose. Molecular mobility values, which are proportional to molecular collision rates, followed the order: acetaminophen > fenofibrate > sucrose > ABT-229 approximately ritonavir. Crystallization studies under nonisothermal conditions revealed that compounds with the highest entropic barriers and lowest mobilities were most difficult to crystallize, regardless of the thermodynamic driving forces. This investigation demonstrates the importance of both configurational entropy and molecular mobility to understanding the physical stability of amorphous pharmaceuticals.

Model-free treatment of the dehydration kinetics of nedocromil sodium trihydrate.

The conventional model-fitting approach to kinetic analysis assumes a fixed mechanism throughout the reaction and therefore may be too simplistic for many solid-state reactions. Even for a reaction with a fixed mechanism, model fitting sometimes cannot identify the reaction model uniquely. The alternative model-free approach is sufficiently flexible to allow for a change of mechanism during the course of a reaction and therefore provides a more realistic treatment of solid-state reactions kinetics. The application of model-free analysis to solid-state dehydrations was investigated using the two consecutive dehydration reactions of nedocromil sodium trihydrate. The complexity of such reactions is illustrated by the variation of the activation energy as each dehydration proceeds. The 1st-step dehydration follows one-dimensional phase boundary kinetics until the fraction dehydrated reaches 0.75, and deviates from this model thereafter. The 2nd-step dehydration follows a mechanism intermediate between two- and three-dimensional diffusion that cannot be described by any of the common models. The model-free approach is clearly better than the model-fitting approach for understanding the details of these solid-state dehydration reactions.

Crystallization kinetics of amorphous nifedipine studied by model-fitting and model-free approaches.

The crystallization of amorphous nifedipine was studied using hot-stage microscopy (HSM), powder X-ray diffractometry (PXRD), and differential scanning calorimetry (DSC). The kinetic data obtained from DSC studies under isothermal and nonisothermal conditions were examined using both model-fitting and model-free approaches. Evaluation of 16 different models showed that model A4 (Avrami-Erofeev, n = 4) to be most appropriate for crystallization in the conversion range 0.05-0.80. This choice was based on the goodness of fit, the residual plots, and the guidance provided by the model-free approach. The model-free approach indicated that the activation energy decreases slightly as the crystallization proceeds. This variation of the activation energy with the extent of conversion determines the range of conversion over which a model can be fit, and the magnitude of the activation energy helps in the selection of the best model. The model-free approach gives much better predictions than the model of best fit and allows the experimental kinetic function to be numerically evaluated. At the early stage (alpha = 0-0.6), the numerically reconstructed model is almost identical to A4, but gradually approaches A3 (Avrami-Erofeev, n = 3) as the crystallization progresses (alpha = 0.6-0.8) and deviates from both models near the end of the reaction. This behavior may be explained by the relative contributions of nucleation and crystal growth at different stages of the reaction.

Crystallization and transitions of sulfamerazine polymorphs.

A bulk powder of sulfamerazine polymorph II in a narrow distribution of particle size was prepared for the first time. The two known sulfamerazine polymorphs, I and II, were physically characterized by optical microscopy, powder X-ray diffractometry, differential scanning calorimetry, carbon-13 solid-state nuclear magnetic resonance spectroscopy, and measurements of aqueous solubility and density. The thermodynamics and kinetics of the transition between the polymorphs was examined under various pharmaceutically relevant conditions, such as heating, cooling, milling, compaction, and contact with solvents. The two polymorphs were found to be enantiotropes with slow kinetics of interconversion. The thermodynamic transition temperature lies between 51 and 54 degrees C, with polymorph II stable at lower temperatures. Ostwald's Rule of Stages explains the crystallization of the polymorphs from various solvents and may account for the delay in the discovery of polymorph II.

Dehydration kinetics of neotame monohydrate.

The dehydration of neotame monohydrate was monitored at various temperatures by differential scanning calorimetry (DSC), thermogravimetry (TGA), hot-stage microscopy (HSM), powder X-ray diffractometry (PXRD), and (13)C solid-state nuclear magnetic resonance (SSNMR) spectroscopy. This work emphasizes kinetic analysis of isothermal TGA data by fitting to various solid-state reaction models and by model-free kinetic treatment. The dehydration of neotame monohydrate follows the kinetics of a two-dimensional phase boundary reaction (R2) at 40-50 degrees C with an activation energy of 75 +/- 9 kJ/mol, agreeing well with 60-80 kJ/mol from model-free kinetics. At a low heating rate in DSC and TGA, neotame monohydrate undergoes dehydration to produce anhydrate Form E, which then converts to anhydrate Form A, followed by the melting of A. Neotame monohydrate under dry nitrogen purge at 50 mL/min undergoes partial isothermal dehydration at 50 degrees C to produce neotame anhydrate Form A. When neotame monohydrate is heated very slowly from 50 to 65-70 degrees C over 24 h, pure Form A is obtained.

Crystal structure and thermal behavior of nedocromil nickel octahydrate.

The hydration behavior of a salt depends on the nature of the cation and the anion and on the molecular packing. A transition metal salt (nickel) of nedocromil was prepared and its crystal structure was elucidated in an attempt to study the influence of the nature of the bivalent cation on the structure, water interactions and molecular packing. Crystal data: nedocromil nickel octahydrate (NNi), orthorhombic, Pca2(1), a=29.5446(1) A, b=25.0444(1) A, c=13.3767(2) A, Z=16. The Ni2+, has octahedral coordination, but the coordination environments of the cations and the bonding environments of the water molecules differ. NNi contains four Ni2+ ions in the asymmetric unit, two of which are each octahedrally coordinated to five water molecules and to a carboxyl oxygen. The two remaining Ni2+ ions are linked in a Ni2(H2O)10(+4) species. Thermal analytical data for NNi show that the water molecules in this hydrate are lost in a single step dehydration, which may be attributed to the fairly continuous water layer in the ac plane of the crystal lattice.

Solid-state characterization of nifedipine solid dispersions.

The purpose of this study is to characterize the nature and solid-state properties of a solid dispersion system of nifedipine (33.3% w/w) in a polymer matrix consisting of Pluronic F68 (33.3% w/w) and Gelucire 50/13 (33.3% w/w). The nature of nifedipine dispersed in the matrix was studied by powder X-ray diffractometry (PXRD), differential scanning calorimetry (DSC) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The rate and extent of water uptake of the solid dispersion were determined by weight gain. The dissolution rate of nifedipine solid dispersion was determined using Apparatus 2 of USP XXIII (1995). Quantitative PXRD showed that the saturation solubility of nifedipine in the polymer matrix is 2.1-3.0% w/w and indicated an excess of crystalline nifedipine in the solid dispersion. The maximum water uptake by the solid dispersion exposed to 75% RH at 45 degrees C was 3.3 times higher than for the dispersion exposed to 65% RH at 25 degrees C. Over 8 weeks, PXRD and DRIFTS of the nifedipine matrix stored at 25 or 4 degrees C were unchanged, showing constancy of crystallinity and intermolecular interactions. For a given mass of nifedipine (20 mg) and for a given particle size of nifedipine (<850 microm), the initial release rate of nifedipine from the solid dispersion was faster (46.2% of the nifedipine dissolved in 20 min) than that of the pure drug (1.2% of the nifedipine dissolved in 20 min). The results indicate that the nifedipine solid dispersion is physically stable over 8 weeks. Nifedipine is released faster from the solid dispersion than from the pure crystalline drug of the same particle size.