Surface dissolution UV imaging for characterization of superdisintegrants and their impact on drug dissolution

Superdisintegrants are a key excipient used in immediate release formulations to promote fast tablet disintegration, therefore understanding the impact of superdisintegrant variability on product performance is important. The current study examined the impact of superdisintegrant critical material attributes (viscosity for sodium starch glycolate (SSG), particle size distribution (PSD) for croscarmellose sodium (CCS)) on their performance (swelling) and on drug dissolution using surface dissolution UV imaging. Acidic and basic pharmacopoeia (compendial) media were used to assess the role of varying pH on superdisintegrant performance and its effect on drug dissolution. A highly soluble (paracetamol) and a poorly soluble (carbamazepine) drug were used as model compounds and drug compacts and drug-excipient compacts were prepared for the dissolution experiments. The presence of a swelled SSG or CCS layer on the compact surface, due to the fast excipient hydration capacity, upon contact with dissolution medium was visualized. The swelling behaviour of superdisintegrants depended on excipient critical material attributes and the pH of the medium. Drug dissolution was faster in presence compared to superdisintegrant absence due to improved compact wetting or compact disintegration. The improvement in drug dissolution was less pronounced with increasing SSG viscosity or CCS particle size. Drug dissolution was slightly more complete in basic compared to acidic conditions in presence of the studied superdisintegrants for the highly soluble drug attributed to the increased excipient hydration capacity and the fast drug release through the swelled excipient structure. The opposite was observed for the poorly soluble drug as potentially the improvement in drug dissolution was compromised by drug release from the highly swelled structure. The use of multivariate data analysis revealed the influential role of excipient and drug properties on the impact of excipient variability on drug dissolution.</p

<i>In vitro - in vivo </i>relations for the parenteral liposomal formulation of Amphotericin B:A clinically relevant approach with PBPK modeling

In vitro release testing is a useful tool for the quality control of controlled release parenteral formulations, but in vitro release test conditions that reflect or are able to predict the in vivo performance are advantageous. Therefore, it is important to investigate the factors that could affect drug release from formulations and relate them to in vivo performance. In this study the effect of media composition including albumin presence, type of buffer and hydrodynamics on drug release were evaluated on a liposomal Amphotericin B formulation (Ambisome®). A physiologically based pharmacokinetic (PBPK) model was developed using plasma concentration profiles from healthy subjects, in order to investigate the impact of each variable from the in vitro release tests on the prediction of the in vivo performance. It was found that albumin presence was the most important factor for the release of Amphotericin B from Ambisome®; both hydrodynamics setups, coupled with the PBPK model, had comparable predictive ability for simulating in vivo plasma concentration profiles. The PBPK model was extrapolated to a hypothetical hypoalbuminaemic population and the Amphotericin B plasma concentration and its activity against fungal cells were simulated. Selected in vitro release tests for these controlled release parenteral formulations were able to predict the in vivo AmB exposure, and this PBPK driven approach to release test development could benefit development of such formulations.</p

An <i>in vitro-in vivo</i> correlation study for nifedipine immediate release capsules administered with water, alcoholic and non-alcoholic beverages:Impact of<i> in vitro </i>dissolution media and hydrodynamics

The impact of hydrodynamics and media composition on nifedipine dissolution profile from IR (immediate release) soft capsules was investigated using dissolution apparatus USP1, USP2, USP3 and USP4 (United State Pharmacopoeia). Media composition was varied in terms of pH and content, to mimic the dosage form intake with water or non-alcoholic beverages (orange juice) and alcoholic beverages (orange juice/ethanol mixture (47% v/v)). Through construction of in vitro–in vivo correlations (IVIVC) with corresponding in vivo data from the literature, it was possible to evaluate the in vitro conditions that are likely to simulate the in vivo formulation behaviour. Both linear and nonlinear correlations were obtained depending on experimental set-ups. Testing of 20 mg nifedipine capsules in FaSSGFst (Fasted State Simulated Gastric Fluid pH 1.6; water administration) produced IVIVC with the USP3 (after time scaling) and USP4 apparatus. IVIVC were obtained for USP2, USP3 and USP4 in FaSSGFoj (Fasted State Simulated Gastric Fluid pH 3.4; orange juice administration). Linear and nonlinear correlations were obtained with the USP1, USP2 and USP3 apparatus when testing the capsules in FaSSGFoj/EtOH (orange juice/ethanol administration). This study highlighted that selection of physiologically relevant dissolution set-ups is critical for predicting the in vivo impact of formulations co-administration with water, non-alcoholic and alcoholic beverages

A review of paediatric injectable drug delivery to inform the study of product acceptability – An introduction

Aim: The EMA defines acceptability as “the overall ability and willingness of the patient to use, and their caregiver to administer, the medicine as intended” [1]. This paper seeks to outline issues of acceptability in relation to injectable therapy, namely intravenous (IV), intramuscular (IM) and subcutaneous (SC) administration routes, and to lay a foundation to identify a minimum set of data that would satisfy Regulatory Authorities when discussing the acceptability of an injectable product. In addition, it will alert drug product developers to other factors that might contribute to good practice, alternative administration strategies and overall adherence to achieve successful treatment. Whilst the term ‘parenteral’ means “outside the intestine” [2,3] and so potentially covers a range of administration routes including intranasal and percutaneous administration, this review focuses on IV, IM and SC administration by injection. The use of indwelling canulae or catheters to reduce venepuncture and facilitate prolonged treatment is common and may impact acceptability [4]. This may be influenced by information provided by the manufacturer but is not always in their direct control. Other injectable products suitable for routes such as intradermal, intra-articular, intraosseous and intrathecal, share the requirement to be acceptable but are not specifically covered in this paper [2,5]

Sex- and smoke-related differences in gastrointestinal transit of cyclosporin A microemulsion capsules

Belgium Herbarium image of Meise Botanic Garden

Investigation and simulation of dissolution with concurrent degradation under healthy and hypoalbuminaemic simulated parenteral conditions- case example Amphotericin B

Guidance on dissolution testing for parenteral formulations is limited and not often related in vivo performance. Critically ill patients represent a target cohort, frequently hypoalbuminaemic, to whom certain parenteral formulations are administered. Amphotericin B (AmB) is a poorly soluble, highly protein-bound drug, available as lipid-based formulations and used in critical illness. The aim of this study was to develop media representing hypoalbuminaemic and healthy plasma, and to understand and simulate the dissolution profile of AmB in biorelevant media. Dissolution media were prepared with bovine serum albumin (BSA) in Krebs-Ringer buffer, and tested in a flow through cell apparatus and a bottle/stirrer setup. Drug activity was tested against Candida albicans. BSA concentration was positively associated with solubility, degradation rate and maximum amount dissolved and negatively associated with dissolution rate constant and antifungal activity. In the bottle/stirrer setup, a biexponential model successfully described simultaneous dissolution and degradation and increased in agitation reduced the discriminatory ability of the test. The hydrodynamics provided by the flow-through cell apparatus was not adequate to dissolve the drug. Establishing discriminating test methods with albumin present in the dissolution media, representing the target population, supports future development of biorelevant and clinically relevant tests for parenteral formulations.<br/