Using Problem-Based Learning in a Chemistry Practical Class for Pharmacy Students and Engaging Them with Feedback

INTRODUCTION

Problem-based learning initially was developed in medical schools as a format for self-directed learning and to acquire problem-solving skills.^1-6 It significantly differs from other learning approaches, where students are equipped with knowledge prior to the exercise.⁷ A mentor provides guidance, monitoring, and feedback to a group of 5-6 students and plays a crucial role within this learning environment.⁸

Schools of pharmacy around the world, including in the United States, Canada, and Europe, increasingly use a PBL-approach for instruction because problem-solving, critical-thinking, and decision-making skills are crucial for pharmacists.^9-11 Problem-based learning often is limited to clinical pharmacy or pharmacology teaching, although some approaches use PBL as an interactive tool within a series of medicinal chemistry lectures.¹²

There are limited examples of a PBL approach being used to teach a large-size chemistry or science practical class at the university level. Examples include using “PBL mini projects” instead of the traditional “prefabricated” chemistry laboratory practical.¹³ Health and safety concerns, staff numbers, and the logistics of managing large class sizes in a laboratory environment with minimal instruction can be limiting factors.

In this paper, we report on the design of a novel medicinal chemistry-based practical class that uses PBL. Problem-based learning is the teaching medium for a number of modules at the University of Reading School of Pharmacy, but this is the first medicinal chemistry laboratory class to use it. The design addresses typical issues found in PBL approaches, such as high staffing needs and the time-consuming aspect of feedback.

DESIGN

The medicinal chemistry module focuses on the use of metal-based drugs in a variety of therapeutic areas. The module hosts up to 150 students and contains traditional lectures, workshops, tutorials, and practical classes. Students are introduced to a variety of elements, a range of inorganic compounds, and the clinical uses of these substances. Students are expected to integrate therapeutic knowledge acquired in Part 1, 2, and 3 with medicinal and analytical chemistry. Part of this module is an 8-hour practical class, which focuses on the quality control of these drugs.

The laboratory classes are designed for 150 students, but still provide the students with the experience of small-group learning. Students typically work in groups of 4-5. The main teaching process is led by 1-2 academic staff facilitators. The groups are also supported by PhD student mentors. Typically, there are 4-6 mentors for the whole cohort, and their main duty is to supervise the laboratory work and to support the student groups in their experimental design and data analysis.

The aim of the practical class is for students to achieve the following learning objectives: research and understand the literature regarding relevant quality assurance procedures; engage with quality assurance protocols and regulations; devise an experimental setup; undertake health and safety risk assessments; perform chemical analysis to a high standard; practice scientific calculations; develop and strengthen understanding of unit conversion and technical limitations; evaluate results in relation to relevant standards; and present outcomes to virtual clients. The practical experiment is one of many elements assessed in this practical class. Emphasis is placed on the process of literature research, in addition to testing understanding of and implementing this information.

Previously, practical classes were designed using a traditional approach. Students were provided with a practical manuscript containing information about the experimental setup and background information, along with health and safety information. An element of interactive learning was to provide students with an online health and safety test. Student engagement with the learning objectives was limited, and the students acted more like consumers rather than active learners. Nevertheless, they still obtained high marks (grades) for the practical element, though this performance was not replicated in the written examination.

Therefore, we decided to design a novel practical class, where students would engage with learning objectives and where a spread of grades, commensurate with a range of abilities, would be achieved. The redesign of the class was supported by the Pharmacy Board of Teaching and Learning, and the analysis of the subsequent outcomes approved by the school’s research ethics committee.

The new PBL chemistry practical class provided students with limited health and safety information and no laboratory manual. The class was divided into groups of 4-5 students. Each group was asked to start their own virtual pharmaceutical company, and they were provided with some dedicated laboratory space containing equipment and chemicals. The groups received a short brief from their virtual client, stating their task. This brief varied according to the lecture material, and it could be tailored to the individual module outcomes.

A typical task was to analyze an active pharmaceutical ingredient (API) in a batch of newly manufactured drugs. The virtual client would ask, for example, if the API quantity was within legally acceptable limits so the manufactured drugs could be released to the market. Other options included identification of the API or the physical testing of the formulation. No further instruction was given. Each virtual company was given a series of forms for communication with the virtual client. This led students through the learning process but did not interfere with the PBL approach.

The choice of the drug determined what experimental elements were practiced in the laboratory. The quantitative analysis of most metal-based drugs was undertaken by a series of titrations. Thus, the preparation of the required standard solutions was a crucial step, as was determining their exact concentrations. Other drugs required UV-Vis analysis, high-performance liquid chromatography (HPLC), potentiometry, etc. Using a drug containing a mixture of APIs, the students also were required to separate individual compounds. Therefore, the complexity of the task could be tailored by the choice of drug.

Typical instruments used included UV-Vis spectrometers, HPLC, or titration glassware. The practical setup varied according to the chosen drug and, therefore, could be tailored to laboratory equipment. Analytical instruction in the pharmacopoeia could typically be undertaken with relatively “simple” equipment. Typically, each group was provided with a different batch of drugs, which meant the API, the formulation, or the strength varied. An example of a practical write-up showing the quantitative analysis of ferrous sulphate is provided in Appendix 1.

Students went through predetermined steps within the PBL scenario as a result of the setup. Within the first 3 weeks students focussed on the Chemistry of the API, and researching the literature for the legal requirements. These are typically the legally binding country-specific pharmacopoeia. Students will have learned how to use these in previous modules. Furthermore, they were required to design their experimental setup and undertake their health and safety assessment. The outcome was their communication with their virtual client about the proposed experimental setup in order to obtain approval. Weeks 4-6 were dedicated to undertaking the quantitative analysis of the API content in their drug. The analytical skills required are taught to students in previous years. Typically, the analysis was based on simple titration, HPLC or UV-Vis analysis. Additionally, the students were required to evaluate their results according to the relevant professional standards and present them to their virtual client. All students had to create a certificate of analysis.

In line with the PBL ethos, each group had access to a mentor, who guided them through initial research, experiments, and evaluation of their results. Group feedback was given to the students on a regular basis either orally from mentors, or more importantly, through written formative feedback via written communication with their virtual clients (written by the facilitator).

The assessment, based on the range of learning, was complex. Students were assessed as a group on a variety of criteria outlined in the marking scheme (Appendix 2). The groups received grades for experimental design, research of the scientific background, health and safety assessment, practical performance, evaluation of their results, and presentation to the virtual client. In addition, students were invited to use peer assessment, which allowed the lead academic of the practical class to assess individual contributions to the work. Some of the learning outcomes are assessed in the end-of-year written examination.

The PBL practice built on students’ prior knowledge of quality control, health and safety assessments, and standard analytical tests obtained from previous lectures and practical classes. Basic knowledge from these previous modules, together with newly acquired information, was applied to the PBL scenario. The students built on their basic knowledge and engaged in self-directed studies to achieve the learning outcomes. Examples for the drug analyses were chosen according to the level of students’ experience.

The practical class was also designed to prepare students for their research project in the final year as the students were introduced to independent research work. The laboratory work was only a small part of the PBL scenario, which placed more emphasis on the whole process and accuracy of such work. The students were, for example, required to find the correct legally binding procedures and to think about accuracy and standardization on a level appropriate for work in a pharmaceutical quality assurance laboratory. All of these skills are important for a successful final year research project.

EVALUATION AND ASSESSMENT

The practical element contributed a total of 20% toward the final module grade at the time of the PBL design. Within the previous traditional practical class, the assessment had been based on the practical work and on report writing, where the latter contributed significantly more to the final grade. Students achieved high marks for the coursework, with averages of 68.6%, 77.3%, 65.2% and 80.7% in previous years.

In addition to the high average grades, there was a poor spread of practical grades as seen in Table 1. In most years, more than half of the cohort received a grade of 70% or better for their coursework. The high coursework grades certainly were not mirrored by excellent performance on the end-of-year written examination. Typically, the examination grade was around 45%, with little variation between cohorts.

We designed the new PBL practical to address these issues, and it appeared to fulfill our expectations, such as engaging students with feedback and integration of knowledge. The average coursework grade was 65.4% in 2013-2014, and the individual grades showed a better spread (Table 1) and followed the typical Gaussian distribution as expected. Also the average examination grade increased significantly to 65% and was in line with the practical grade.

Students actively participated in this practical class based on student feedback comments we received and on high attendance rate (98%). All feedback sessions provided during the PBL process were well-attended, and students came prepared to address the previous feedback comments. It became clear in the module evaluation that the practical was perceived as challenging but also as a useful teaching tool.

The design directed students to fully understand the different steps of the practical, such as literature research, health and safety protocols, experimental process, and calculations. A lack of engagement at any stage would have resulted in an incomplete report submission. In turn, students who struggled in the initial steps were still able to pick up good grades if they engaged at a later stage as a result of responding to feedback.

DISCUSSION

The new practical class was designed to engage students and mirror real-life working situations. It was important to choose relevant real-life scenarios to motivate students, and students engaged well with this practical. Attendance at the practical classes was 98%, despite no grade allocation for attendance. All student groups submitted their report on time; late submission would have resulted in a penalty, according to standard university policy. To evaluate the new problem-based learning model described, students had the opportunity to complete a feedback form at the end of the course, and we had a return rate of 76%.

In general, students found the practical class interesting but also challenging and relevant to their future professional career. Negative comments on the initial offering concerned the weighting of coursework to module grade as students felt that the coursework had become more work intensive. This was addressed for subsequent student cohorts by adjusting the weighting of examination to coursework within the module.

Evaluation of the coursework grades showed the majority of students achieved between 60% and 69.9%. The general grade distribution followed the typical Gaussian distribution. This overcame one of the problems of the previous practical design.

The facilitator, leading the teaching experience, and mentor, supporting the teaching experience, play an important role in any PBL scenario. Within this PBL practical class, each group was allocated a mentor, who supported the group during experimental design, throughout the laboratory work, and for the final submission of reports to the virtual client. We observed that mentors played an invaluable role in guiding the work, without significantly influencing the students’ work. Communicating with their peers and mentors allowed students to practice their communication skills. Group work, especially organizing this challenging practical, also prepares students for real-life scenarios, where working as part of a team (eg, multi-disciplinary health-care teams) would be essential. Additionally, the PBL approach encouraged logical thinking, which promotes problem-solving skills.

Potential health and safety concerns about allowing a large cohort (150 students) into a laboratory without a strict instruction manual were addressed. The experimental design had to be submitted for approval before the laboratory work could take place. The design of the experimental setup also was restricted; students only had access to a limited variety of chemicals and equipment to minimize risk.

The workload for academic staff members who facilitated the course did not significantly increase, compared with a typical medicinal chemistry practical. Leading this practical for 150 students required 1-2 academic staff members supported by 4-6 mentors, in addition to the technical staff, which is typical for a chemistry practical class of this size.

Nevertheless, the timing of grading and feedback provision was shifted to occur alongside the PBL process. Within a traditional chemistry practical, marking and feedback takes place after the learning process. Often, feedback is significantly delayed because of the large class sizes, which in return minimizes the opportunities to meet learning outcomes for the students. This novel practical design required that the majority of grading be completed before students went into the laboratory. In turn, the grading and written feedback after the practical classes was significantly reduced. The workload distribution for the academic staff was rather unusual for a practical class, but expected for a PBL approach.

It is crucial for students to engage with feedback to progress within this practical as there are no written instruction manuals. If the students do not fully engage with the feedback, the practical class becomes more challenging. This relationship between provided feedback and the students engaging with feedback is an important aspect of the practical session, as other studies report that students request feedback, but are not able to act on the feedback given.^14-16

Assessment of a PBL scenario is always a point for discussion, and this was no different for this practical class. Student groups received feedback and grades for researching and understanding the literature and designing the experimental setup. They were also evaluated on their health and safety assessment, their practical performance, evaluation of their results, and their presentation to their client. To facilitate such a complex assessment and feedback for a cohort of 150 students, we developed a grading scheme that took all the grading criteria into account and contained a short comment box for each criterion. These comments were given to students during the process and grades were only released as one final grade at the end of the practical to engage students with the feedback and not the grade itself. Student learning efforts often are centered on grades and not the feedback given.¹⁷

A potential weakness of this PBL practical compared to a traditional practical class is that students were exposed to a less varied hands-on experience. A significant proportion of the time was spent on research and working with the scenario. In comparison, in a traditional laboratory class, the students spend most of their time performing 3-4 experiments. Problem-based learning is a more time-consuming learning process.¹⁸ Furthermore, the learning outcomes for a PBL laboratory class differ significantly from those of a traditional experimental class and are much more diverse.

From a teaching perspective, this practical class design can integrate knowledge and experiences from a variety of modules. The concept of curricular integration is emerging in modern education, and it is required for the university training of future pharmacists.¹⁹ Professional and regulatory bodies around the world demand an integrated teaching approach to equip the health care professional with the competencies to deal with a myriad of medical conditions in a large and complex health care system while not forgetting the needs of the patient.^20,21

CONCLUSION

The successful design of a PBL-based medicinal chemistry laboratory class allowed students to engage in real-life scenarios and interact with a virtual client. This laboratory class enabled the students to apply procedures relevant to quality control in the pharmaceutical industry by integrating a variety of knowledge acquired prior to the session. The PBL approach encouraged students to actively approach a variety of learning outcomes. Rather than a learning facts passively, students had to engage in self-directed learning and the feedback provided, and apply the information learned. The PBL-based practical class ensured that the learning process and feedback provision were aligned to maximize student experience. The detailed grading scheme made the feedback provision easy and effective, which may enable this practical design to be used for large class sizes.