Impact on intestinal permeability of pediatric hyperosmolar formulations after dilution: Studies with rat perfusion method

Pharmacokinetics of oral versus intravenous ibuprofen for closure of patent ductus arteriosus: A pilot randomised controlled study

AIM

This pilot study aimed to compare the pharmacokinetic profiles of oral (PO) and intravenous (IV) ibuprofen for treatment of patent ductus arteriosus (PDA) in preterm neonates.

METHODS

In a single-centre, parallel, randomised open-label trial, neonates ≤35 weeks, weight <1800 g with haemodynamically significant PDA during the first week of life were recruited between June 2017 and February 2019 and randomised to receive either PO or IV ibuprofen at standard dosage of 10, 5 and 5 mg/kg every 24 h for three consecutive days. Plasma concentrations of ibuprofen were quantified using a validated high-performance liquid chromatography method and pharmacokinetic parameters were calculated. Treatment outcomes were recorded.

RESULTS

Eleven neonates participated in the trial, six and five patients receiving PO and IV ibuprofen, respectively. Pharmacokinetic analysis reveals similar ibuprofen exposure levels in treatment groups. Median dose- and weight-normalised C_max values of PO and IV groups were 2.12 and 2.53 g/mL respectively (P = 0.082) and median AUC_0-24 levels were comparable (PO: 34.6 g*h/mL vs. IV: 50.7.6 g*h/mL, P = 0.25).

CONCLUSION

This exploratory study demonstrates comparable pharmacokinetics of PO and IV formulations of ibuprofen in preterm neonates. Larger prospective studies are required to validate these findings.

Effect of Ingested Fluid Volume and Solution Osmolality on Intestinal Drug Absorption: Impact on Drug Interaction with Beverages

It was recently shown that osmolality-dependent fluid movement is a significant factor causing the clinically observed apple juice (AJ)-atenolol interaction. Here we examined whether osmolality-dependent fluid movement may also explain the AJ volume dependence of the AJ-atenolol interaction. In Wistar rats, the luminal fluid volume after administration of different volumes of purified water (0.5 and 1.0 mL) gradually reduced to a similar steady-state level, while that after administration of different volumes of AJ (0.5 and 1.0 mL) increased and attained different apparent steady-state levels. It was hypothesized that osmolality-dependent fluid secretion would account for the volume dependence of the apparent steady-state. Indeed, the luminal concentration of FD-4, a non-permeable compound, after administration in AJ was attenuated depending upon the ingested volume, whereas that after administration in purified water was independent of the ingested fluid volume. An in vivo pharmacokinetic study in rats showed that co-administration of AJ and hyperosmotic solution (adjusted to the osmolality of AJ) with atenolol volume-dependently reduced the AUC and C_max of atenolol significantly. These results show that osmolality-dependent variations in luminal fluid volume may indirectly influence the absorption characteristics of drugs, and can account for the observed volume dependence of beverage-drug interactions.

Potential pharmacokinetic interaction between orally administered drug and osmotically active excipients in pediatric polypharmacy

Poorly absorbable sugar alcohols (e.g., mannitol, sorbitol, and maltitol) are the excipients frequently contained in pediatric dosage forms. Due to their osmotically active properties, certain amount of sugar alcohols reportedly reduces oral bioavailability of concomitant drugs. This fact implies the possible pharmacokinetic interaction between orally administered drug and sugar alcohols which are present in other concomitant medications. The purpose of this study was to identify the possibility and likeliness of the osmotically active excipient-induced pharmacokinetic interaction in pediatric polypharmacy. Previously developed in silico model that captured the osmotic effect of sugar alcohols in adults was expanded to pediatric population. This mathematical model successfully explained the impaired bioavailability of lamivudine by the co-administered sorbitol in other dosage forms. In the meantime, sugar alcohol contents in marketed pediatric dosage forms were investigated by reverse engineering technology. Considering the critical administration dose of sugar alcohols estimated by in silico model, it was revealed that 25 out of 153 pediatric dosage forms were identified as possible perpetrators even under the approved administration and dosage in Japan. This study shed light on the potential pharmacokinetic interaction that cannot be dismissed throughout the pediatric pharmaceutical dosage form design and development.

Effect of excipients on oral absorption process according to the different gastrointestinal segments

INTRODUCTION

Excipients are necessary to develop oral dosage forms of any Active Pharmaceutical Ingredient (API). Traditionally, excipients have been considered inactive and inert substances, but, over the years, numerous studies have contradicted this belief. This review focuses on the effect of excipients on the physiological variables affecting oral absorption along the different segments of the gastrointestinal tract. The effect of excipients on the segmental absorption variables are illustrated with examples to help understand the complexity of predicting their in vivo effects.

AREAS COVERED

The effects of excipients on disintegration, solubility and dissolution, transit time, and absorption are analyzed in the context of the different gastrointestinal segments and the physiological factors affecting release and membrane permeation. The experimental techniques used to study excipient effects and their human predictive ability are reviewed.

EXPERT OPINION

The observed effects of excipient in oral absorption process have been characterized in the past, mainly in vitro (i.e. in dissolution studies, in vitro cell culture methods or in situ animal studies). Unfortunately, a clear link with their effects in vivo, i.e. their impact on Cmax or AUC, which need a mechanistic approach is still missing. The information compiled in this review leads to the conclusion that the effect of excipients in API oral absorption and bioavailability is undeniable and shows the need of implementing standardized and reproducible preclinical tools coupled with mechanistic and predictive physiological-based models to improve the current empirical retrospective approach.

Availability of Authorizations from EMA and FDA for Age-Appropriate Medicines Contained in the WHO Essential Medicines List for Children 2019

Lack of age-appropriate commercially drug products availability is a common problem in pediatric therapeutics; this population needs improved and safer drug delivery. In addition, biopharmaceutic aspects, dosage requirements, and swallowing abilities demand pediatric forms different to adult formulations. The objective of this study was to evaluate the authorization availability from United States Food and Drug Administration (FDA) and European Medicines Agency (EMA) of oral essential medicines for children and analyze its age-appropriateness for oral administration in children. All oral drugs from 7th List of Essential Medicines for Children by World Health Organization (WHO) were selected. Availability of commercial drug products was collected from OrangeBook, Spanish drug product catalogue, British electronic Medicines Compendium, and the International Vademecum. Tablets, effervescent tablets, and capsules were considered as not age-appropriate forms. Liquid forms, powder for oral suspension, mini tablets, granules, and soluble films were considered as age-appropriate forms due to their flexibility. More than 80% of the studied drugs possess a commercial authorization in oral forms in both EMA and FDA. Nevertheless, around 50% of these formulations are not age-appropriate for most pediatric groups. This study shows the lack of age-appropriate medicines for children. More efforts are needed to improve development and approval of pediatric medicines.