Co-Processed Excipients for Dispersible Tablets-Part 1: Manufacturability.

Co-processed excipients may enhance functionality and reduce drawbacks of traditional excipients for the manufacture of tablets on a commercial scale. The following study aimed to characterise a range of co-processed excipients that may prove suitable for dispersible tablet formulations prepared by direct compression. Co-processed excipients were lubricated and compressed into 10.5-mm convex tablets using a Phoenix compaction simulator. Compression profiles were generated by varying the compression force applied to the formulation and the prepared tablets were characterised for hardness, friability, disintegration and fineness of dispersion. Our data indicates that CombiLac, F-Melt type C and SmartEx QD100 were the top 3 most suitable out of 16 co-processed excipients under the conditions evaluated. They exhibited good flow properties (Carr's index ˂ 20), excellent tabletability (tensile strength > 3.0 MPa at 0.85 solid fraction), very low friability (< 1% after 15 min), rapid disintegration times (27-49 s) and produced dispersions of ideal fineness (< 250 µm). Other co-processed excipients (including F-Melt type M, Ludiflash, MicroceLac, Pharmaburst 500 and Avicel HFE-102) may be appropriate for dispersible tablets produced by direct compression providing the identified disintegration and dispersion risks were mitigated prior to commercialisation. This indicates that robust dispersible tablets which disintegrate rapidly could be manufactured from a range of co-processed excipients.

Co-Processed Excipients for Dispersible Tablets-Part 2: Patient Acceptability.

Palatability and patient acceptability are critical attributes of dispersible tablet formulation. Co-processed excipients could provide improved organoleptic profile due to rational choice of excipients and manufacturing techniques. The aim of this study was to identify the most suitable co-processed excipient to use within directly compressible dispersible tablet formulations. Nine excipients, selected based on successful manufacturability, were investigated in a randomised, preference and acceptability testing in 24 healthy adult volunteers. Excipients were classified in order of preference as follows (from most preferred): SmartEx QD100 > F-Melt Type C > F-Melt Type M > MicroceLac > Ludiflash > CombiLac > Pharmaburst 500 > Avicel HFE-102 > Avicel PH-102. Broad differences were identified in terms of acceptability, with SmartEx QD100 being 'very acceptable', F-Melt Type C, F-Melt Type M and MicroceLac being 'acceptable', Ludiflash, CombiLac and Pharmaburst 500 being 'neutral' and Avicel products being 'very unacceptable' based on ratings using five-point hedonic scales. Organoleptic differences were ascribed to different composition and physical properties of excipients, resulting in dissimilar taste and mouth-feel. Excipients with particle size in water larger than 200-250 µm were considered poorly acceptable, which supports the use of this value as a threshold for maximum particle size of dispersible formulation. The most promising co-processed excipients for directly compressible dispersible tablets were successfully identified.

Amorphous formulations of indomethacin and griseofulvin prepared by electrospinning.

Following an array of optimization experiments, two series of electrospun polyvinylpyrrolidone (PVP) fibers were prepared. One set of fibers contained various loadings of indomethacin, known to form stable glasses, and the other griseofulvin (a poor glass former). Drug loadings of up to 33% w/w were achieved. Electron microscopy data showed the fibers largely to comprise smooth and uniform cylinders, with evidence for solvent droplets in some samples. In all cases, the drug was found to exist in the amorphous physical state in the fibers on the basis of X-ray diffraction and differential scanning calorimetry (DSC) measurements. Modulated temperature DSC showed that the relationship between a formulation's glass transition temperature (Tg) and the drug loading follows the Gordon-Taylor equation, but not the Fox equation. The results of Gordon-Taylor analysis indicated that the drug/polymer interactions were stronger with indomethacin. The interactions between drug and polymer were explored in more detail using molecular modeling simulations and again found to be stronger with indomethacin; the presence of significant intermolecular forces was further confirmed using IR spectroscopy. The amorphous form of both drugs was found to be stable after storage of the fibers for 8 months in a desiccator (relative humidity <25%). Finally, the functional performance of the fibers was studied; in all cases, the drug-loaded fibers released their drug cargo very rapidly, offering accelerated dissolution over the pure drug.

The effect of administration media on palatability and ease of swallowing of multiparticulate formulations.

Multiparticulate formulations based on pellets, granules or beads, could be advantageous for paediatrics, geriatrics and patients with swallowing difficulties. However, these formulations may require suitable administration media to facilitate administration. The aim of this work was to investigate the effect of administration media properties on palatability and ease of swallowing of multiparticulates. A range of vehicles were developed using xanthan gum (XG) and carboxymethyl cellulose (CMC) as model hydrocolloids. Such vehicles were prepared at three consistency levels (Level 1 - 'syrup', Level 2 - 'custard' and Level 3 - 'pudding') to investigate the effect of viscosity on their performance as administration media. A randomised, single-blind sensory evaluation study was carried out in thirty healthy adult volunteers using microcrystalline cellulose pellets as model multiparticulates, dispersed in the hydrogels (and water as control) at a concentration of 250 mg in 5 ml. Samples were evaluated using 5-point scales. The use of hydrogels as administration media improved a range of sample attributes compared to water formulations, including appearance, taste, mouthfeel, ease of swallowing and residue in the mouth (all improved by ca. 0,5 points) and oral grittiness perception (improved by ca. 1 point). Polymeric hydrogels thickened to medium consistency (Level 2, XG 0.5% and CMC 1.0% w/v) demonstrated the best performance.

Acceptability of placebo multiparticulate formulations in children and adults.

Patient acceptability is an important consideration in the design of medicines for children. The aim of this study was to investigate acceptability of multiparticulates in healthy children and adults. A randomised, single-blind acceptability testing was performed involving 71 children (4-12 years) and 61 adults (18-37 years). Each participant received three 500 mg samples of microcrystalline cellulose pellets administered on a medicine spoon with water at 5-10 minutes intervals. Acceptability was measured based on voluntary intake of the samples, facial expressions, ratings on hedonic scales and reported willingness to take multiparticulates everyday as a medicine. Multiparticulates were voluntarily swallowed by 92% of children and 100% of adults. However, palatability issues were identified, with emphasis on textural aspects. Grittiness perception received negative ratings on hedonic scales by 60% of children and 51% of adults. Researcher observations revealed that 72% of children and 42% of adults displayed negative facial expressions towards the samples. Children reported their willingness to take multiparticulates as a medicine in 30% of the cases, compared to 74% in adults. This study demonstrates that multiparticulates may be a suitable formulation platform for children and adults, although palatability concerns have been highlighted. Additional work is required to define acceptability criteria and to standardise methodologies.

Effect of formulation variables on oral grittiness and preferences of multiparticulate formulations in adult volunteers.

Multiparticulate formulations are composed of multiple solid dosage units which can be administered directly to the mouth or sprinkled on food. Oral grittiness (i.e. rough mouthfeel) may arise from the presence of particles in the mouth, limiting palatability. In this work, multiparticulate formulations were prepared by dispersion of spherical granules into orange flavoured vehicles thickened with hypromellose (HPMC) at different viscosities in order to assess oral perception of grittiness by a panel of thirty adults through direct scaling on a 100mm visual analogue scale. The effect of formulation factors such as particle size (90, 127, 263µm), amount of particles per 10ml (0.25, 0.50, 1.00g) and viscosity of the vehicle (0.08, 0.43, 2.80Pas) were investigated. Grittiness was increasingly perceived with increasing amount and size of particles. Increasing viscosity of the administration media had a masking effect on the perception of particles. Less gritty samples were generally regarded as 'more pleasant' by the participants of the study. However, samples dispersed in thickened vehicles seemed to be less preferred despite being less gritty; which could be ascribed to an unpleasant mouthfeel of the vehicle. In the design of multiparticulate formulations acceptable for a targeted patient group all these formulation factors will need to be considered and optimised.

Patient centric formulations for paediatrics and geriatrics: Similarities and differences.

Paediatrics and geriatrics both represent highly heterogenous populations and require special consideration when developing appropriate dosage forms. This paper discusses similarities, differences and considerations with respect to the development of appropriate medicine formulations for paediatrics and geriatrics. Arguably the most significant compliance challenge in older people is polypharmacy, whereas for children the largest barrier is taste. Pharmaceutical technology has progressed rapidly and technologies including FDCs, multi-particulates and orodispersible dosage forms provide unprecedented opportunities to develop novel and appropriate formulations for both old and new drugs. However, it is important for the formulation scientists to work closely with patients, carers and clinicians to develop such formulations for both the paediatric and geriatric population.

Formulation approaches to pediatric oral drug delivery: benefits and limitations of current platforms.

INTRODUCTION: Most conventional drug delivery systems are not acceptable for pediatric patients as they differ in their developmental status and dosing requirements from other subsets of the population. Technology platforms are required to aid the development of age-appropriate medicines to maximize patient acceptability while maintaining safety, efficacy, accessibility and affordability. AREAS COVERED: The current approaches and novel developments in the field of age-appropriate drug delivery for pediatric patients are critically discussed including patient-centric formulations, administration devices and packaging systems. EXPERT OPINION: Despite the incentives provided by recent regulatory modifications and the efforts of formulation scientists, there is still a need for implementation of pharmaceutical technologies that enable the manufacture of licensed age-appropriate formulations. Harmonization of endeavors from regulators, industry and academia by sharing learning associated with data obtained from pediatric investigation plans, product development pathways and scientific projects would be the way forward to speed up bench-to-market age appropriate formulation development. A collaborative approach will benefit not only pediatrics, but other patient populations such as geriatrics would also benefit from an accelerated patient-centric approach to drug delivery.