Solid dispersion technology represents a successful approach to addressing the bioavailability issues caused by the low aqueous solubility of many Biopharmaceutics Classification System (BCS) Class II drugs. In this study, the use of high-yield manufacture of fiber-based dispersion is explored as an alternative approach to monolith production methods. A temperature-controlled solvent-free centrifugal spinning process was used to produce sucrose-based microfibers containing the poorly water-soluble drugs olanzapine and piroxicam (both BCS Class II); these were successfully incorporated into the microfibers and the basic characteristics of fiber diameter, glassy behavior, drug loading capacity and drug-sucrose interaction assessment were measured. Scanning electron microscopy revealed that bead-free drug-loaded microfibers with homogenous morphology and diameter in the range of a few micrometers were prepared using our process. Differential scanning calorimetric and X-ray diffraction analyses showed that both drug and carrier were present in the amorphous state in the microfibers, although in the case of piroxicam-loaded microfibers, the presence of small amounts of crystalline drug was observed under polarized light microscopy and in Fourier transform infrared spectra. Drug dissolution performance was evaluated under both sink and non-sink conditions and was found to be significantly enhanced compared to the corresponding crystalline physical mixtures and pure drugs, with evidence of supersaturation behavior noted under non-sink conditions. This study has demonstrated that microfiber-based dispersions may be manufactured by the centrifugal spinning process and may possess characteristics that are favorable for the enhanced dissolution and oral absorption of drugs.

Older people represent a very heterogeneous patient population and are the major user group of medication. Age-related changes mean that this population can encounter barriers towards taking medicines orally. The aim of this study was to investigate the characteristics of oral solid dosage forms that contribute to an age appropriate dosage design, with an aim to improve overall medication adherence and acceptance in older people. Fifty-two semistructured interviews were conducted with older people, informal (family) carers, and health and social care professionals. Formulation characteristics impacted three stages of the medication taking process: (1) medication identification and memorability, (2) medication handling and (3) swallowability. Small round tablets (≤7 mm) are least accepted amongst older people and their carers and had a negative impact on all stages. The use of bright, two-coloured preparations and interesting shapes improves identification and further aids memorability of indications and the timing of tablets. Palatability, while useful to enhance swallowability, also has an impact on the visual appeal and memorability of medication. Environmental, patient, medication and disease characteristics also determine preferences for formulation. Developing an age appropriate dosage design for older people, therefore, requires a holistic, patient-centric approach to improve adherence and acceptance.

Hydrophilic matrices are widely used for extended release drug delivery, with hypromellose (HPMC) being a popular rate-controlling carrier. The FDA has recently issued an alert regarding the potential negative influence of alcohol on extended release dosage forms. The aim of this study was to investigate the hydroalcoholic solution effect on hydration, gel formation and drug release from HPMC matrices. None of the investigated matrix formulations (felodipine, gliclazide, and metformin hydrochloride) resulted in dose-dumping when exposed to ethanol solutions. HPMC compacts made of three different viscosity grades of Methocel showed consistent swelling and gel formation when exposed to hydroalcoholic media.

The majority of active pharmaceutical ingredients (APIs) are bitter. Therefore, compliance can be a problem where adequate taste masking has not been achieved; this is most problematic in paediatrics. Taste masking is thus a key stage during pharmaceutical development with an array of strategies available to the formulation scientist. Solid oral dosage forms can be taste-masked quite simply by polymer coating, which prevents drug release in the mouth, without unwantedly impairing drug release further down the gastrointestinal tract. At the early stages of pharmaceutical development, an in vitro method for assessment of taste masking is necessary given the lack of toxicological data preventing the use of human taste panels. Currently there is no such tool allowing prediction of taste masking efficiency. In this study, drug dissolution in the context of aversive taste thresholds was proposed as a means to bridge this knowledge gap. Thus, a biorelevant buccal dissolution test was developed in which previously determined taste thresholds in vivo were used to evaluate taste masking efficiency: if drug release exceeded said thresholds, the formulation was deemed to be poorly taste-masked, and vice versa. This novel dissolution test was compared to the USP I (basket) dissolution test, and the biopharmaceutical implications of taste masking were also assessed by performing USP I (basket) dissolution testing in simulated gastric fluid (SGF). Chlorphenamine maleate (CPM), a model bitter BCS class 1 API, was layered onto sugar spheres and taste-masked using polymer coatings. An array of coating technologies were employed and assessed single blinded: two pH independent water insoluble coatings (Surelease®:Opadry® at 8, 12 and 16% weight gain and Opadry EC at 4, 6 and 8% weight gain) and a pH dependent water insoluble reverse enteric coating (developmental fully formulated system based on Kollicoat® Smartseal 100P at 10% weight gain). Both the biorelevant buccal and the USP I dissolution tests were capable of discriminating between both type and level of coating used. However, only the buccal dissolution test was able to provide absolute quantification of the level of taste masking achieved in the context of previously determined taste thresholds, while the USP I test merely provided a relative comparison between the different technologies assessed. When the release data from the buccal test were assessed in parallel to that in SGF, it was possible to predict in vitro optimised taste masking without compromising bioavailability. The fully formulated system based on Smartseal 100P was identified as the most effective coating and Surelease:Opadry the least effective. The developed methodology provides true insight for the formulator, enabling more informed patient-centric formulation decisions, better taste masking and ultimately more effective medicines.