Using Mechanistic Modeling Approaches to Support Bioequivalence Assessments for Oral Products

This report summarizes the proceedings for Day 1 Session 3 of the 2-day public workshop entitled "Best Practices for Utilizing Modeling Approaches to Support Generic Product Development," a jointly sponsored workshop by the US Food and Drug Administration (FDA) and the Center for Research on Complex Generics (CRCG) in the year 2022. The aims of this workshop were to discuss how to modernize approaches for efficiently demonstrating bioequivalence (BE), to establish their role in modern paradigms of generic drug development, and to explore and develop best practices for the use of modeling and simulation approaches in regulatory submissions and approval. The theme of this session is mechanistic modeling approaches supporting BE assessments for oral drug products. As a summary, with more successful cases of PBPK absorption modeling being developed and shared, the general strategies/frameworks on using PBPK for oral products are being formed; this will help further evolvement of this area. In addition, the early communications between the industry and the agency through appropriate pathways (e.g., pre-abbreviated new drug applications (pre-ANDA) meetings) are encouraged, and this will speed up the successful development and utility of PBPK modeling for oral products.

The pipeline for drugs for control and elimination of neglected tropical diseases: 2. Oral anti-infective drugs and drug combinations for off-label use

In its 'Road map for neglected tropical diseases 2021-2030', the World Health Organization outlined its targets for control and elimination of neglected tropical diseases (NTDs) and research needed to achieve them. For many NTDs, this includes research for new treatment options for case management and/or preventive chemotherapy. Our review of small-molecule anti-infective drugs recently approved by a stringent regulatory authority (SRA) or in at least Phase 2 clinical development for regulatory approval showed that this pipeline cannot deliver all new treatments needed. WHO guidelines and country policies show that drugs may be recommended for control and elimination for NTDs for which they are not SRA approved (i.e. for 'off-label' use) if efficacy and safety data for the relevant NTD are considered sufficient by WHO and country authorities. Here, we are providing an overview of clinical research in the past 10 years evaluating the anti-infective efficacy of oral small-molecule drugs for NTD(s) for which they are neither SRA approved, nor included in current WHO strategies nor, considering the research sponsors, likely to be registered with a SRA for that NTD, if found to be effective and safe. No such research has been done for yaws, guinea worm, Trypanosoma brucei gambiense human African trypanosomiasis (HAT), rabies, trachoma, visceral leishmaniasis, mycetoma, T. b. rhodesiense HAT, echinococcosis, taeniasis/cysticercosis or scabies. Oral drugs evaluated include sparfloxacin and acedapsone for leprosy; rifampicin, rifapentin and moxifloxacin for onchocerciasis; imatinib and levamisole for loiasis; itraconazole, fluconazole, ketoconazole, posaconazole, ravuconazole and disulfiram for Chagas disease, doxycycline and rifampicin for lymphatic filariasis; arterolane, piperaquine, artesunate, artemether, lumefantrine and mefloquine for schistosomiasis; ivermectin, tribendimidine, pyrantel, oxantel and nitazoxanide for soil-transmitted helminths including strongyloidiasis; chloroquine, ivermectin, balapiravir, ribavirin, celgosivir, UV-4B, ivermectin and doxycycline for dengue; streptomycin, amoxicillin, clavulanate for Buruli ulcer; fluconazole and isavuconazonium for mycoses; clarithromycin and dapsone for cutaneous leishmaniasis; and tribendimidine, albendazole, mebendazole and nitazoxanide for foodborne trematodiasis. Additional paths to identification of new treatment options are needed. One promising path is exploitation of the worldwide experience with 'off-label' treatment of diseases with insufficient treatment options as pursued by the 'CURE ID' initiative.

Dosimetric Analysis of Patients Treated with Stereotactic Body Radiation Therapy for Malignant Portal Vein Tumor Thrombosis Using MRI-Guided vs. CT-Guided Linear Accelerator

PURPOSE/OBJECTIVE(S)

The use of MRI-guided linear accelerators (MRI-LINAC) for radiation therapy has allowed for increased treatment precision and real-time tumor tracking. We hypothesized that the use of an MRI-LINAC, recently acquired by our institution, would allow us to treat malignant portal vein tumor thromboses (PVTT) closer to the origin of the portal vein with similar doses to the liver and nearby GI organs and with similar treatment toxicities compared to patients treated using a CT-guided linear accelerator (CT-LINAC).

MATERIALS/METHODS

We retrospectively assessed patients who received SBRT for treatment of PVTT within the UVA health system using the electronic medical record. We contoured the origin of the portal vein on the simulation scans (MRI or CT) for each patient. The shortest distance from the GTV to the portal vein origin and to organs at risk (OAR; duodenum, stomach or "other intestine") were measured. The PTV, volume of the liver receiving less than 18 Gy during treatment, and the Dmax to the portal vein origin and OAR were determined. The means for each variable were then compared between CT-LINAC and MRI-LINAC using independent samples t-tests. Treatment toxicities were graded using CTCAE version 5.0 guidelines. All plans met institutional dose constraints for SBRT.

RESULTS

A total of 6 patients treated on CT-LINAC and 3 patients treated on MRI-LINAC were identified (mean dose CT 37.7 Gy [range 21-50] in 2-5 fractions; MRI 48.3 Gy [range 45-50] in 5 fractions). The GTV was significantly closer to the portal vein origin in the MRI-LINAC group (mean CT 92.75 mm ± 45.89; MRI 32.00 mm ± 29.46; p = 0.04). The GTV trended towards being closer to OAR in the MRI-LINAC group (mean CT 43.81 mm ± 37.09; MRI 4.36 mm ± 1.85; p = 0.059). The Dmax to both the portal vein origin (mean CT 0.58 Gy ± 0.33; MRI 22.49 Gy ±24.16; p = 0.024) and OAR (mean CT 13.38 Gy ± 5.98; MRI 36.23 Gy ± 5.38; p = <0.001) was significantly higher in the MRI-LINAC group. The PTV (mean CT 152.11 cc ± 169.94; MRI 122.47 cc ± 114.65; p = 0.398) or volume of liver receiving less than 18 Gy during treatment (mean CT 1287.87 cc ± 285.20; MRI 1743.88 cc ±961.94 = 3; p = 0.147) were not significantly different between the two groups. No patients in either the MRI-LINAC or CT-LINAC group reported acute toxicities greater than Grade 1.

CONCLUSION

We found that patients with PVTT treated with MRI-LINAC SBRT at our institution were more likely to have central tumors near dose-limiting OAR. However, due to superior tumor delineation and dynamic tumor tracking, these patients were able to be treated without decreasing treatment dose or increasing acute GI toxicity compared to patients treated with CT-LINAC. A larger sample size and longer follow-up period is warranted to corroborate these initial findings.

Optimizing expert and patient input in pediatric trial design: Lessons learned and recommendations from a collaboration between conect4children and European Patient-CEntric ClinicAl TRial PLatforms

Advice from multiple stakeholders is required to design the optimal pediatric clinical trial. We present recommendations for acquiring advice from trial experts and patients/caregivers, derived from advice meetings that were performed through a collaboration of the Collaborative Network for European Clinical Trials for Children (c4c) and the European Patient-CEntric ClinicAl TRial PLatforms (EU-PEARL). Three advice meetings were performed: (1) an advice meeting for clinical and methodology experts, (2) an advice meeting for patients/caregivers, and (3) a combined meeting with both experts and patients/caregivers. Trial experts were recruited from c4c database. Patients/caregivers were recruited through a patient organization. Participants were asked to provide input on a trial protocol, including endpoints, outcomes, and the assessment schedule. Ten experts, 10 patients, and 13 caregivers participated. The advice meetings resulted in modification of eligibility criteria and outcome measures. We have provided recommendations for the most effective meeting type per protocol topic. Topics with limited options for patient input were most efficiently discussed in expert advice meetings. Other topics benefit from patient/caregiver input, either through a combined meeting with experts or a patients/caregivers-only advice meeting. Some topics, such as endpoints and outcome measures, are suitable for all meeting types. Combined sessions profit from synergy between experts and patients/caregivers, balancing input on protocol scientific feasibility and acceptability. Both experts and patients/caregivers provided critical input on the presented protocol. The combined meeting was the most effective methodology for most protocol topics. The presented methodology can be used effectively to acquire expert and patient feedback.

Colour of Medicines and Children's Acceptability? A Systematic Literature Review of Children's Perceptions about Colours of Oral Dosage Forms

The colour of a product plays an important role in consumer experiences, and in the context of pharmaceutical products, this could potentially affect a patient's expectations, behaviours, and adherence. Several studies have been conducted on adults, but little is known about children's opinions on colours of medicines and to what extent medicines' colour affects their acceptability. To address this gap, a systematic search in PubMed, Scopus, MEDLINE, and Web of Science was conducted. Two authors independently screened the titles, abstracts, and references of all articles and selected studies conducted on children (0-18 years old), assessing children's preferences or opinions about colour of oral dosage forms as either a primary or secondary objective or as an anecdotal record. A total of 989 publications were identified and, after screening, 18 publications were included in the review. Red and pink were the most liked colours and there appeared to be a relationship between the colour of a medicine and expected taste/flavour. The review also highlighted a scarcity of information, usually collected as an anecdotal record. Several gaps in the current knowledge were underlined, emphasizing the need of patient-centred studies to understand if the use of certain colours can improve or worsen the acceptability of a paediatric medicine. This will help inform pharmaceutical manufacturers and regulators on the role and need of colours in children's medicines beyond quality purposes.

The pipeline for drugs for control and elimination of neglected tropical diseases: 1. Anti-infective drugs for regulatory registration

The World Health Organization 'Ending the neglect to attain the Sustainable Development Goals: A road map for neglected tropical diseases 2021-2030' outlines the targets for control and elimination of neglected tropical diseases (NTDs). New drugs are needed to achieve some of them. We are providing an overview of the pipeline for new anti-infective drugs for regulatory registration and steps to effective use for NTD control and elimination. Considering drugs approved for an NTD by at least one stringent regulatory authority: fexinidazole, included in WHO guidelines for Trypanosoma brucei gambiense African trypanosomiasis, is in development for Chagas disease. Moxidectin, registered in 2018 for treatment of individuals ≥ 12 years old with onchocerciasis, is undergoing studies to extend the indication to 4-11-year-old children and obtain additional data to inform WHO and endemic countries' decisions on moxidectin inclusion in guidelines and policies. Moxidectin is also being evaluated for other NTDs. Considering drugs in at least Phase 2 clinical development, a submission is being prepared for registration of acoziborole as an oral treatment for first and second stage T.b. gambiense African trypanosomiasis. Bedaquiline, registered for tuberculosis, is being evaluated for multibacillary leprosy. Phase 2 studies of emodepside and flubentylosin in O. volvulus-infected individuals are ongoing; studies for Trichuris trichuria and hookworm are planned. A trial of fosravuconazole in Madurella mycetomatis-infected patients is ongoing. JNJ-64281802 is undergoing Phase 2 trials for reducing dengue viral load. Studies are ongoing or planned to evaluate oxantel pamoate for onchocerciasis and soil-transmitted helminths, including Trichuris, and oxfendazole for onchocerciasis, Fasciola hepatica, Taenia solium cysticercosis, Echinococcus granulosus and soil-transmitted helminths, including Trichuris. Additional steps from first registration to effective use for NTD control and elimination include country registrations, possibly additional studies to inform WHO guidelines and country policies, and implementation research to address barriers to effective use of new drugs. Relative to the number of people suffering from NTDs, the pipeline is small. Close collaboration and exchange of experience among all stakeholders developing drugs for NTDs may increase the probability that the current pipeline will translate into new drugs effectively implemented in affected countries.

Practical and operational considerations related to paediatric oral drug formulation: an industry survey

For over 15 years, US and EU regulations ensure that medicines developed for children are explicitly authorised for such use with age-appropriate forms and formulations, implying dedicated research. To shed light on how these regulations have been adopted by pharmaceutical companies and how various aspects of paediatric oral drug formulation development are currently handled, an exploratory survey was conducted. Topics included: general company policy, regulatory aspects, dosage form selection, in-vitro, in-silico and (non-)clinical in-vivo methods, and food effects assessment. The survey results clearly underline the positive impact of the paediatric regulations and their overall uptake across the pharmaceutical industry. Even though significant improvements have been made in paediatric product development, major challenges remain. In this respect, dosage form selection faces a discrepancy between the youngest age groups (liquid products preference) and older subpopulations (adult formulation preference). Additionally, concerted research is needed in the development and validation of in-vitro tools and physiology based pharmacokinetic models tailored to the paediatric population, and in estimating the effect of non-standard and paediatric relevant foods. The current momentum in paediatric drug development and research should allow for an evolution in standardised methodology and guidance to develop paediatric formulations, which would benefit pharmaceutical industry and regulators.

In vitro models to evaluate ingestible devices: Present status and current trends

Orally ingestible medical devices offer significant opportunity in the diagnosis and treatment of gastrointestinal conditions. Their development necessitates the use of models that simulate the gastrointestinal environment on both a macro and micro scale. An evolution in scientific technology has enabled a wide range of in vitro, ex vivo and in vivo models to be developed that replicate the gastrointestinal tract. This review describes the landscape of the existing range of in vitro tools that are available to characterize ingestible devices. Models are presented with details on their benefits and limitations with regards to the evaluation of ingestible devices and examples of their use in the evaluation of such devices is presented where available. The multitude of models available provides a suite of tools that can be used in the evaluation of ingestible devices that should be selected on the functionality of the device and the mechanism of its function.

In vivo models to evaluate ingestible devices: Present status and current trends

Evaluation of orally ingestible devices is critical to optimize their performance early in development. Using animals as a pre-clinical tool can provide useful information on functionality, yet it is important to recognize that animal gastrointestinal physiology, pathophysiology and anatomy can differ to that in humans and that the most suitable species needs to be selected to inform the evaluation. There has been a move towards in vitro and in silico models rather than animal models in line with the 3Rs (Replacement, Reduction and Refinement) as well as the better control and reproducibility associated with these systems. However, there are still instances where animal models provide the greatest understanding. This paper provides an overview of key aspects of human gastrointestinal anatomy and physiology and compares parameters to those reported in animal species. The value of each species can be determined based upon the parameter of interest from the ingested device when considering the use of pre-clinical animal testing.

Path towards efficient paediatric formulation development based on partnering with clinical pharmacologists and clinicians, a conect4children expert group white paper

Improved global access to novel age-appropriate formulations for paediatric subsets, either of new chemical entities or existing drugs, is a priority to ensure that medicines meet the needs of these patients. However, despite regulatory incentives, the introduction to the market of paediatric formulations still lags behind adult products. This is mainly caused by additional complexities associated with the development of acceptable age-appropriate paediatric medicines. This position paper recommends the use of a paediatric Quality Target Product Profile as an efficient tool to facilitate early planning and decision making across all teams involved in paediatric formulation development during the children-centric formulation design for new chemical entities, or to repurpose/reformulate off-patent drugs. Essential key attributes of a paediatric formulation are suggested and described. Moreover, greater collaboration between formulation experts and clinical colleagues, including healthcare professionals, is advocated to lead to safe and effective, age-appropriate medicinal products. Acceptability testing should be a secondary endpoint in paediatric clinical trials to ensure postmarketing adherence is not compromised by a lack of acceptability. Not knowing the indications and the related age groups and potential dosing regimens early enough is still a major hurdle for efficient paediatric formulation development; however, the proposed paediatric Quality Target Product Profile could be a valuable collaborative tool for planning and decision making to expedite paediatric product development, particularly for those with limited experience in developing a paediatric product.

Current challenges and future perspectives in oral absorption research: An opinion of the UNGAP network

Although oral drug delivery is the preferred administration route and has been used for centuries, modern drug discovery and development pipelines challenge conventional formulation approaches and highlight the insufficient mechanistic understanding of processes critical to oral drug absorption. This review presents the opinion of UNGAP scientists on four key themes across the oral absorption landscape: (1) specific patient populations, (2) regional differences in the gastrointestinal tract, (3) advanced formulations and (4) food-drug interactions. The differences of oral absorption in pediatric and geriatric populations, the specific issues in colonic absorption, the formulation approaches for poorly water-soluble (small molecules) and poorly permeable (peptides, RNA etc.) drugs, as well as the vast realm of food effects, are some of the topics discussed in detail. The identified controversies and gaps in the current understanding of gastrointestinal absorption-related processes are used to create a roadmap for the future of oral drug absorption research.

A review of in vitro and in vivo methods and their correlations to assess mouthfeel of solid oral dosage forms

This review analyses the relationship between instrumental and human data used to assess the mouthfeel of solid oral dosage forms to provide recommendations on the most appropriate methods to use in future studies.

Determination of healthcare resource and cost implications of using alternative sodium valproate formulations in the treatment of epilepsy in children in England: A retrospective database review

OBJECTIVES

The aim of this study was to compare the adherence, healthcare resource and cost implications of using Episenta® minitablets or Epilim® monolithic tablet in the treatment of epilepsy in children in England.

DESIGN

This is a retrospective analysis of healthcare administrative databases.

SETTING

The study analysed data collected from Primary Care (Clinical Practice Research Datalink (CPRD)) and Secondary Care (Hospital Episode Statistics (HES)) in England, UK.

PARTICIPANTS

Patients (stratified by age 0-12; 0-17 and 18+ years) with a diagnosis of epilepsy in receipt of a new prescription for Episenta® minitablets or Epilim® monolithic tablet from January 2012 to October 2017. Limited to those with a minimum of 12 months follow-up.

MAIN OUTCOME MEASURES

Determining the impact of sodium valproate formulation on measures of treatment adherence and healthcare resource usage.

RESULTS

There were 793 patients in the dataset: 84 on Episenta® minitablets and 709 on Epilim® tablets. Measures of medication adherence were not significantly different between the minitablet formulation and the monolithic matrix tablet. However there was a greater annualised incidence rate of epilepsy related primary healthcare contacts in a paediatric population from the tablet formulation compared to those treated with minitablets (95% CI [-1.561,0.0152]) for those aged 0-12 and (95% CI [-1.3234,-0.0058]) for those aged 0-17. This is found despite a lower dose being used in the minitablet cohort (595 mg vs 945 mg for the tablet) for those aged 0-17 which indicates effective therapy at a lower dose using the minitablet compared to the monolithic tablet formulation.

CONCLUSIONS

Minitablet formulations of sodium valproate (presented as granules in capsules or sachets) can provide better therapeutic outcomes and reduced associated healthcare resource costs compared to monolithic tablets in children and young people with epilepsy. The interpretation of this data is limited by the large difference in sample size between the two groups which needs additional investigation to generate matched data for future comparisons. Further work is required to understand why the Episenta® minitablets formulation generated better outcomes in paediatric populations.

Characterisation of fasted state gastric and intestinal fluids collected from children

Fundamental knowledge about the composition of intestinal fluids in paediatric populations is currently unavailable. This study aimed to characterise gastric and intestinal fluid from paediatric populations. Gastric and intestinal fluid samples were obtained during routine clinical endoscopy from paediatric patients at a large teaching hospital. These fluids were characterised to measure the pH; buffer capacity; osmolality; bile acid concentration and composition. A total of 55 children were recruited to the study aged from 11 months to 15 years of age where 53 gastric fluid samples and 40 intestinal fluid samples were obtained. pH values recorded ranged from pH 0.57 to 11.05 (median: 2.50) in gastric fluids and from 0.89 to 8.97 (median: 3.27) in intestinal fluids. The buffer capacity did not change significantly between gastric and intestinal fluids with median values of 12 mM/L/ΔpH for both fluids. Gastric fluid osmolality values ranged from 1 to 615 mOsm/kg, while intestinal fluid values ranged from 35 to 631 mOsm/kg. Gastric fluid bile acid concentrations ranged from 0.002 to 2.3 mM with a median value of 0.017 mM whilst intestinal fluid bile acid concentrations ranged from 0.0008 to 3.3 mM with a median value of 0.178 mM. Glycocholate; taurocholic acid; glycochenodeoxycholate and taurochenodeoxycholate were the most commonly identified bile acids within paediatric intestinal fluids. All compositional components were associated with large inter-individual variability. Further work is required to develop simulated paediatric media and to explore the impact of these media on drug solubility and dissolution.

The RabGAPs TBC1D1 and TBC1D4 Control Uptake of Long-Chain Fatty Acids Into Skeletal Muscle via Fatty Acid Transporter SLC27A4/FATP4

The two closely related RabGTPase-activating proteins (RabGAPs) TBC1D1 and TBC1D4 play a crucial role in the regulation of GLUT4 translocation in response to insulin and contraction in skeletal muscle. In mice, deficiency in one or both RabGAPs leads to reduced insulin- and contraction-stimulated glucose uptake and to elevated fatty acid (FA) uptake and oxidation in both glycolytic and oxidative muscle fibers without altering mitochondrial copy number and the abundance of proteins for oxidative phosphorylation. Here we present evidence for a novel mechanism of skeletal muscle lipid utilization involving the two RabGAPs and the FA transporter SLC27A4/FATP4. Both RabGAPs control the uptake of saturated and unsaturated long-chain FAs (LCFAs) into skeletal muscle and knockdown (Kd) of a subset of RabGAP substrates, Rab8, Rab10, or Rab14, decreased LCFA uptake into these cells. In skeletal muscle from Tbc1d1 and Tbc1d4 knockout animals, SLC27A4/FATP4 abundance was increased and depletion of SLC27A4/FATP4 but not FAT/CD36 completely abrogated the enhanced FA oxidation in RabGAP-deficient skeletal muscle and cultivated C2C12 myotubes. Collectively, our data demonstrate that RabGAP-mediated control of skeletal muscle lipid metabolism converges with glucose metabolism at the level of downstream RabGTPases and involves regulated transport of LCFAs via SLC27A4/FATP4.

Making Medicines Baby Size: The Challenges in Bridging the Formulation Gap in Neonatal Medicine

The development of age-appropriate formulations should focus on dosage forms that can deliver variable yet accurate doses that are safe and acceptable to the child, are matched to his/her development and ability, and avoid medication errors. However, in the past decade, the medication needs of neonates have largely been neglected. The aim of this review is to expand on what differentiates the needs of preterm and term neonates from those of the older paediatric subsets, in terms of environment of care, ability to measure and administer the dose (from the perspective of the patient and carer, the routes of administration, the device and the product), neonatal biopharmaceutics and regulatory challenges. This review offers insight into those challenges posed by the formulation of medicinal products for neonatal patients in order to support the development of clinically relevant products.

Evaluation of patient-reported outcome measurements as a reliable tool to measure acceptability of the taste of paediatric medicines in an inpatient paediatric population

OBJECTIVE

To evaluate the age appropriateness and suitability of patient-reported outcome measures to assess the acceptability of the taste of oral liquid medicines in children.

DESIGN AND SETTING

An observational mixed-methods study involving children aged 2-16 years taking oral liquid medicine in paediatric inpatient wards across the West Midlands (UK). Assessment tools included patient-reported scores on the taste of medicines via a five-point Facial Hedonic Scale; a Visual Analogue Scale (VAS); a question, 'Did you think the medicine tasted OK?' and researcher observations of facial expressions and behaviours immediately before, during and after administration.

RESULTS

611 children participated. The percent unable to complete the scales was 7% (n=46) for the VAS; 2% (n=15) for the hedonic scale and 1% (n=7) for the question about taste. Significant correlations (Spearman's r) were observed between the patient-reported outcome measures: 0.80 and 0.78 for the taste question and hedonic and VAS, respectively, and 0.84 for the hedonic and VAS. Researcher observations demonstrated the ability of the patient to take the medicine as intended but did not provide sensitive measures of taste. 5% of administrations were not taken as intended by the children. Medicines known to have poor taste (clarithromycin and prednisolone) showed mean hedonic and VAS scores of ≥3.5 and >65 mm, respectively.

CONCLUSIONS

Patient-reported outcome measures correlate with each other and are a useful means to assess the taste (and acceptability) of medicines. Hedonic scales are better understood by children and should be the first choice tool in the assessment of medicines taste.

Food effects in paediatric medicines development for products Co-administered with food

A small amount of food is commonly used to aid administration of medicines to children to improve palatability and/or swallowability. However the impact of this co-administered food on the absorption and subsequent pharmacokinetic profile of the drug is unknown. Existing information on food effects is limited to standard protocols used to evaluate the impact of a high fat meal in an adult population using the adult medication. In the absence of a substantial body of data, there are no specific guidelines available during development of paediatric products relating to low volumes of potentially low calorie food. This paper brings together expertise to consider how the impact of co-administered food can be risk assessed during the development of a paediatric medicine. Two case studies were used to facilitate discussions and seek out commonalities in risk assessing paediatric products; these case studies used model drugs that differed in their solubility, a poorly soluble drug that demonstrated a positive food effect in adults and a highly soluble drug where a negative food effect was observed. For poorly soluble drugs risk assessments are centred upon understanding the impact of food on the in vivo solubility of the drug which requires knowledge of the composition of the food and the volumes present within the paediatric gastrointestinal tract. Further work is required to develop age appropriate in vitro and in silico models that are representative of paediatric populations. For soluble drugs it is more important to understand the mechanisms that may lead to a food effect, this may include interactions with transporters or the impact of the food composition on gastro-intestinal transit or even altered gastric motility. In silico models have the most promise for highly soluble drug products although it is essential that these models reflect the relevant mechanisms involved in potential food effects. The development of appropriate in vitro and in silico tools is limited by the lack of available clinical data that is critical to validate any tool. Further work is required to identify globally acceptable and available vehicles that should be the first option for co-administration with medicines to enable rapid and relevant risk assessment.

European Paediatric Formulation Initiative (EuPFI)-Formulating Ideas for Better Medicines for Children

The European Paediatric Formulation Initiative (EuPFI), founded in 2007, aims to promote and facilitate the preparation of better and safe medicines for children through linking research and information dissemination. It brings together the capabilities of the industry, academics, hospitals, and regulators within a common platform in order to scope the solid understanding of the major issues, which will underpin the progress towards the future of paediatric medicines we want.The EuPFI was formed in parallel to the adoption of regulations within the EU and USA and has served as a community that drives research and dissemination through publications and the organisation of annual conferences. The membership and reach of this group have grown since its inception in 2007 and continue to develop and evolve to meet the continuing needs and ambitions of research into and development of age appropriate medicines. Five diverse workstreams (age-appropriate medicines, Biopharmaceutics, Administration Devices, Excipients and Taste Assessment & Taste Masking (TATM)) direct specific workpackages on behalf of the EuPFI. Furthermore, EuPFI interacts with multiple diverse professional groups across the globe to ensure efficient working in the area of paediatric medicines. Strong commitment and active involvement of all EuPFI stakeholders have proved to be vital to effectively address knowledge gaps related to paediatric medicines, discuss potential areas for further research and identify issues that need more attention and analysis in the future.

ASSESSMENT OF VANCOMYCIN CONCENTRATIONS IN SYRINGES PREPARED WITHIN A WARD SETTING

AIM

Vancomycin is used as a second line antibiotic in the treatment of late onset neonatal infection for its activity against coagulase negative staphylococci. Vancomycin infusions are prepared within a ward setting for administration to neonates. Differences in preparation techniques on the ward have previously been recognised as a potential source of variation in vancomycin concentrations, as compared to concentrations in pre-made preparations. This study analyses a consecutive series of vancomycin syringes prepared in a ward for administration to neonates, to determine how accurate the concentration of each preparation was compared to the expected concentration.

METHOD

Vancomycin concentrations were determined by UV analysis (λ=280 nm) with a UV spectrophotometer (Jenway Genova Plus). A calibration curve for vancomycin was created (R2=0.9996) by manufacturing a series of solutions of vancomycin hydrochloride in glucose 5% w/v.Samples of vancomycin from syringes from which doses were administered to neonates were then analysed to assess their concentration. For each syringe, mean vancomycin concentration±standard deviation was calculated (n=3).Reasonable errors in preparations were calculated based on errors in each step of the preparation process. Theoretical error was calculated based on apparatus used, and experimental error was recorded based on a simulated process. Two preparation methods were compared; the method complying with that described in the local formulary, 1 and an alternative method reported by the nurses preparing the dose.

RESULTS

Analysis of results showed that concentration of the vancomycin syringes prepared ranged from 0.85 to 8.24 mg/mL. The expected concentration was 4.17 mg/ml.Theoretical error in preparation of vancomycin doses was lower with the formulary-compliant method1 versus an alternative method, as were variations in in vancomycin concentration.Depending on the type of error (theoretical or experimental) and method by which vancomycin syringes were prepared (formulary1 or alternative method), the percentage of syringes with vancomycin concentration outside of the specified ranges varied from 20%-43%. This is higher compared to the findings of the Department of Health2, where it was found that 19.2% of morphine infusions prepared by nurses in the neonatal intensive care unit were outside British Pharmacopoeia concentration limits.

CONCLUSION

Preparation of vancomycin doses should follow the formulary method1 to minimise variation in concentration of the final product. Alternatively, pre-made syringes may be preferred as an alternative to ward-made syringes as this removes individualised preparation as a source of error.

CHILDREN WITH CYSTIC FIBROSIS: UNDERSTANDING ISSUES RELATED TO ORAL ADMINISTRATION OF LIQUID FLUCLOXACILLIN

AIM

Palatability of flucloxacillin is poor, yet is used long-term in the management of children with cystic fibrosis (CF). Strategies to aid administration of unpalatable medicines have been reported, however there has never been a systematic approach to gathering views of many parents/carers all administering the same medication to the same population of children. This study aimed to quantify the extent of flucloxacillin palatability issues for parents/cares of children with CF and identify parent/carer and healthcare professional (HCP) reported age-specific strategies to aid administration of flucloxacillin to children with CF.

METHOD

Passive analysis reviews of public online forums were conducted using search terms including, 'flucloxacillin' and 'taste' or 'palatability' or 'child' to identify evidence of tactics used by parents to aid administration of flucloxacillin to children, not only those with CF (strategies were only included if the age of the child was disclosed). A bespoke online questionnaire was developed and partially validated for parents/carers of children with CF to identify age-specific strategies to aid administration of flucloxacillin. Healthcare professionals (HCPs) were purposively selected for semi-structured interviews to further explore age-specific strategies to aid administration of flucloxacillin.

RESULTS

18 individual strategies were identified on 10 different public online forums to aid the administration of flucloxacillin to children. These included mixing with food/drink: milk was commonly used for children aged 6-20 months; honey, Nutella, jam, ice cream and squash for those aged 21-36 months. The use of an oral syringe to direct the medicine slowly into the back/side of the mouth, and pinching a child's nose was reported.253 parents/carers of children with CF completed the online survey and 11 HCPs were involved in the semi-structured interviews. 50.2% of parents/carers reported that administration of flucloxacillin was problematic, yet 89.3% reported that they administered 'most' or 'all doses' of flucloxacillin. 90.5% of parents/carers found administration of flucloxacillin more problematic than other medicines in pre-weaned babies. 162 of 253 parents/carers chose to comment on ways that administration of flucloxacillin could be improved/eased, with 38.3% of these respondents suggesting improved palatability was necessary. Mixing with food/drink was rarely reported by parents/carers of children with CF (15.9%) or HCPs (27.3%), contrary to data identified within online forums. This difference highlights that parents of children with CF are less likely to use food to aid administration compared to those using flucloxacillin for acute infections. A multi-methods approach to obtain information on manipulation of medicines by parents/carers would provide greater insights into explaining this finding.

CONCLUSION

The results from this study showed that flucloxacillin is unpalatable and that parents/carers use a range of strategies to improve acceptability of this product. Although food is an obvious strategy for making flucloxacillin more palatable when treating an acute infection; it may be that this doesn't work in longer term therapy (eg CF) and the wider population can learn from parents/carers with more experience with this medicine. Parents of children with CF and HCPs have provided useful age-specific strategies to ease administration of the known poorly tolerated medicine, liquid flucloxacillin.

COMPARISON OF HYDROCORTISONE 10 MG TABLETS: TABLET HARDNESS OPTIMISED FOR ADULT USE HAS NEGATIVE CONSEQUENCES FOR PAEDIATRIC USE

BACKGROUND

Children's medicines are not always readily available as an age appropriate product and manipulation of adult products is often required. Recently the commercial manufacturing process for 10 mg hydrocortisone tablets has changed and the compression force increased due to tablets fracturing on removal from the blister pack. However, this change led to parents of children requiring hydrocortisone reporting that the tablets were more difficult to manipulate.This study evaluated 10 mg hydrocortisone tablets for their suitability for manipulation in order to deliver an appropriate dose to children (2 mg dose). The physical properties of tablets with the old and new compression force were compared as well as the accuracy of obtaining the paediatric dose.

METHODS

The tablets compared were hydrocortisone Auden 10 mg tablets (Brand A, PL16876/002)-these are the newer, harder tablets- and hydrocortisone 10 mg tablets (Brand B, PL17507/0097). Tablet physical properties including friability (Copley FRV200) and tablet hardness (Copley TBF1000) were compared. The accuracy of split doses (halve and quarter tablets) were recorded on a Sartorius analytical balance. The accuracy of the 2 mg paediatric dosing was assessed by crushing the tablet, adding 10 mL of water and extracting 2 mL. The concentration was measured using UV analysis (Jenway Genova Plus) according to a calibration curve (wavelength=246 nm). Two devices were used to crush the tablets: a spoon onto a plate and a commercially available crushing device (Apothecary Ezy Crush Pill Crusher With Ergo Grip).

RESULTS

As anticipated Brand A tablets were harder (51.85 ±5.1 N) compared to Brand B (30.99±4.1 N). Brand A tablets passed the friability testing with <1% weight loss whereas Brand B failed as 5 tablets broke during testing.The accuracy of split doses using the score lines to halve and quarter the tablets showed that Brand A were generally better with smaller ranges for both halves (Range for A=41-55%; B=29-70%) and quarters (Range for A=17-35%; B=12-42%) compared to Brand B.The 2 mg dosing accuracy was better for Brand B tablets compared to A and crushing tablets using a commercial device improved the accuracy of dosing for both brands of tablets. When crushing using a spoon the mean dose obtained was 1.3 mg for Brand A and 1.7 mg for Brand B; the commercial crushing device gave values of 1.9 mg for Brand A and 2.1 mg for Brand B.

CONCLUSION

Parents or carers who are required to manipulate 10 mg hydrocortisone tablets to administer a dose to children dispersed in water should be advised to crush the tablet into a fine powder where possible to improve the likelihood of administering an accurate dose. This is particularly important since the introduction of new hydrocortisone Auden tablets which are known to be harder tablets and therefore more force is required to crush these.

ACKNOWLEDGEMENTS

Some of the experimental work within this project was conducted by Andrew Hackett and Kameron Paul-Thaper whilst at the University of Birmingham on work experience from Arden Sixth Form, Station Rd, Knowle, Solihull, West Midlands, B93 0PT.

Evidence of acceptability of oral paediatric medicines: a review

OBJECTIVES

The aim of this review was to map the currently available evidence on acceptability of oral paediatric medicines to aid in the selection of suitable platform formulations for the development of new acceptable paediatric products.

METHODS

This process used a defined search strategy of indexed publications and included methods to assess the quality of the evidence retrieved.

KEY FINDINGS

Taste/palatability was the most extensively studied area of paediatric medicine acceptability yet standard methods or criteria that define what is classed as acceptable to children is still to be defined. There have been many reports on the acceptability of medicines to paediatric populations yet major gaps in the acceptability knowledge base exist including the shape and dimensions of tablets, minitablets and capsules swallowed whole in infants and children; size and overall volume of multiparticulates; volume of liquids completely swallowed in infants and children; duration of retention within the oral cavity, size and taste of orodispersible tablets, lozenges and chewable tablets and the number of solid units dosed at each time point.

CONCLUSIONS

The review highlights where further information is required to support knowledge around acceptability of age-appropriate medicines. An algorithm to aid in selection of a formulation that is likely to be acceptable based on the age range to be treated by the medicine is presented as a result of this review.

Towards the development of a paediatric biopharmaceutics classification system: Results of a survey of experts

The aim of this research survey was to understand current global thinking around the need for and development of a paediatric biopharmaceutics classification system (pBCS) to be used for the development of paediatric medicines and regulatory purposes (e.g. Biowaivers). A literature review highlighted the paucity of data in this area and therefore a survey was developed to better understand this topic to identify areas of common thinking and highlight future research needs. Global experts in paediatric biopharmaceutics were identified from existing networks and public forums. An online survey was developed and circulated broadly to maximise participation. Sixty individuals (including academics, health care professionals, pharmaceutical industry scientists and regulators) completed the survey, bringing together their views on the need for a pBCS. The results highlighted that the area of greatest concern was the definition of BCS II and IV drugs within this population and additional research is required to generate evidence to underpin this issue. In questions relating to permeability and dissolution consensus was generally reached within the expert population suggesting that little additional research is required to define suitable criteria. More than 90% of those experts who participated agreed that a pBCS would be useful for paediatric populations with a greater need identified for the younger populations (newborn and infants compared to adolescents). The results presented will facilitate further discussion and research into the evidence to underpin a relevant pBCS. These results highlight the need for additional evidence and guidance in this area.

Barriers to administering non-oral formulations in a paediatric population: A semi-structured interview study

There is a paucity of research exploring barriers to non-oral medicines administration in paediatric patients; however, these undoubtedly influence medicines adherence. Studies conducted with healthcare professionals have identified various issues with the administration and acceptance of non-oral medicines and devices (Venables et al., 2012; Walsh et al., 2015). EMA (2014) guidelines specify that formulation teams should demonstrate 'acceptability' of paediatric formulations when developing pharmaceutical formulations. Semi-structured interviews exploring barriers to administering non-oral medicines were conducted with young persons and the parents/legal guardians of children (0-17 years) with chronic conditions at the University Hospital of Coventry and Warwickshire, UK. 90 children prescribed a total of 148 non-oral medicines were recruited to the study; 88 barriers to administering non-oral medicines were reported. The most commonly reported barriers were: poor acceptance of face mask/difficulties with spacer for inhaled formulations (38% of reports); disliking parenteral/preferring alternative formulations (38% of reports); greasy texture of topical preparations; difficulty with administering an ocular ointment and the large dose volume of a nasal preparation. Formulation teams should consider the use of child-friendly, age-appropriate designs to improve usability and acceptance, thus medicines adherence. These findings should be used to inform future development of non-oral formulations and devices, suitable in terms of safety, efficacy and acceptability to paediatric patients.

Determination of formulation factors that affect oral medicines acceptability in a domiciliary paediatric population

Acceptability of medicines for children is a challenge, yet critical to ensure adherence to treatment. There is very little literature on formulation factors that influence acceptability of medicines, particularly in the domiciliary environment. This pragmatic study was conducted at University Hospital Coventry and Warwickshire (UHCW) with the aim of identifying the prevalence and nature of oral formulation-related barriers to medicines administration in children suffering from long-term conditions. This study used semi-structured face-to-face interviews with 221 parents/carers of children (0-18 years) and 57 young people (12-18 years).

RESULT

showed significant medicines refusal and manipulation in the domiciliary environment. Nearly one-third (71/232) of respondents reported medicines refusal. This was associated significantly with the age of child (p=0.016), socioeconomic status (IMD 2010 score) (p=0.002), taste (p<0.001), texture (p=0.017), and volume (of liquid/powder) or quantity (of solid dosage form) (p<0.001). 29% (74/252) of respondents reported manipulating medicines. P-values are based on multivariable statistical analysis models. This study has indicated that formulations prescribed to children with chronic conditions are not meeting the needs of a significant number of patients based on self-report. Age-appropriate medicines are required to provide suitable dose units with an acceptable taste for children. This study should aid pharmaceutical companies to prioritise paediatric formulation work.

Physicochemical characterisation, drug polymer dissolution and in vitro evaluation of phenacetin and phenylbutazone solid dispersions with polyethylene glycol 8000

Poor water solubility leads to low dissolution rate and consequently, it can limit bioavailability. Solid dispersions, where the drug is dispersed into an inert, hydrophilic polymer matrix can enhance drug dissolution. Solid dispersions were prepared using phenacetin and phenylbutazone as model drugs with polyethylene glycol (PEG) 8000 (carrier), by melt fusion method. Phenacetin and phenylbutazone displayed an increase in the dissolution rate when formulated as solid dispersions as compared with their physical mixture and drug alone counterparts. Characterisation of the solid dispersions was performed using differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). DSC studies revealed that drugs were present in the amorphous form within the solid dispersions. FTIR spectra for the solid dispersions of drugs suggested that there was a lack of interaction between PEG 8000 and the drug. However, the physical mixture of phenacetin with PEG 8000 indicated the formation of hydrogen bond between phenacetin and the carrier. Permeability of phenacetin and phenylbutazone was higher for solid dispersions as compared with that of drug alone across Caco-2 cell monolayers. Permeability studies have shown that both phenacetin and phenylbutazone, and their solid dispersions can be categorised as well-absorbed compounds.

Bioadhesive Dosage Forms for Esophageal Drug Delivery

The esophagus as a site for drug delivery has been much overlooked in comparison to the remainder of the gastrointestinal tract. The low permeability and transient nature of the esophagus means that it is unsuitable for delivery of drugs for systemic action. However, esophageal disorders including fungal infection, cancers, motility dysfunction, and damage due to gastric reflux may be treated using locally acting agents that offer benefits of reduced dosage and decreased side effects. Bioadhesive dosage forms that adhere to the esophageal mucosa and prolong contact have been investigated to improve the efficacy of locally acting agents. The rationale for local esophageal drug delivery and its limitations, the factors that determine adhesion to this organ, and the experimental models used in esophageal drug delivery research are reviewed.

Bioadhesive oesophageal bandages: protection against acid and pepsin injury

The rate of acid and pepsin diffusion through solutions of sodium alginate was measured using in vitro techniques. Previous work has demonstrated that solutions of alginate may adhere to the oesophagus for up to 60 min; this work measured their ability to protect the oesophageal epithelial surface from damage caused by refluxed acid and pepsin. Franz diffusion cells were used to measure the rate of acid and pepsin diffusion through an alginate layer. The effect of the type of alginate, alginate concentration and depth of alginate applied were investigated. The rate of both acid and pepsin diffusion was significantly reduced (ANOVA analysis; P<0.05) in the presence of an alginate solution compared to the control. A 2% (w/v) alginate solution with a high guluronic acid component, in a layer of 0.44 mm depth, demonstrated the greatest reduction in acid diffusion with a permeation coefficient 14% than that of a control value. All three alginates demonstrated significant reductions in acid diffusion with both increasing depth and increasing concentration, as expected. Pepsin diffusion was also significantly reduced as the depth and concentration of applied alginate increased. This study demonstrates that an adhesive layer of alginate present within the oesophagus will limit the contact of refluxed acid and pepsin with the epithelial surface.

Microscopic techniques as potential tools to quantify the extent of bioadhesion of liquid systems

This work demonstrates the potential of fluorescence and confocal microscopy as techniques to quantify both the extent and duration of bioadhesion of alginate solutions to porcine oesophageal tissue using an in vitro model. The retention of low (40 kDa), medium (240 kDa) and high (416 kDa) MW alginates was quantified via three methods of analysis. Fluorimetric analysis of the dose removed from the oesophageal surface suggested that the percentage of the original dose retained at 30 min was 7.9 +/- 7.0%, 21.9 +/- 9.5% and 23.7 +/- 5.8% for the alginates in order of increasing MW. Analysis of the dose adhered at 30 min using fluorescence microscopy demonstrated that 5.5 +/- 1.9%, 7.1 +/- 2.7% and 18.2 +/- 1.7% of the original dose of the alginate solutions was retained at 30 min. The results found using confocal microscopy showed that the percentage of the original dose adhered at 30 min of the low, medium and high MW alginates were 4.5 +/- 1.9%, 7.2 +/- 5.3% and 11.8 +/- 4.3%, respectively. All techniques demonstrated significantly greater retention of the high MW solution at 30 min compared to the low MW solution. Both confocal and fluorescence microscopy may be used as techniques to evaluate the bioadhesion of liquid systems.