Pediatric dosing for locally acting drugs in submissions to the U.S. Food and Drug Administration between 2002 and 2020.

Deriving pediatric doses for locally acting drugs (LADs) presents a unique challenge because limited systemic exposure hinders commonly used approaches such as pharmacokinetic matching to adults. This study systematically evaluated drug development practices used for pediatric dose selection of LADs approved by the U.S.

In Vitro Skin Permeation Methodology for Over-The-Counter Topical Dermatologic Products.

For topically applied over-the-counter (OTC) products, the association of unwanted systemic exposure and adverse events may be difficult to ascertain without a recognition or determination of in vivo absorption. Evaluation of skin permeability using a validated in vitro permeation methodology can provide important information for both initial formulation selection and reformulation during the product life cycle. Additionally, a comparison of permeation rates between formulations using a validated methodology could reduce the number of nonclinical studies needed as part of reformulation.

Effect of Sunscreen Application on Plasma Concentration of Sunscreen Active Ingredients: A Randomized Clinical Trial.

Importance: A prior pilot study demonstrated the systemic absorption of 4 sunscreen active ingredients; additional studies are needed to determine the systemic absorption of additional active ingredients and how quickly systemic exposure exceeds 0.5 ng/mL as recommended by the US Food and Drug Administration (FDA).

Objective: To assess the systemic absorption and pharmacokinetics of the 6 active ingredients (avobenzone, oxybenzone, octocrylene, homosalate, octisalate, and octinoxate) in 4 sunscreen products under single- and maximal-use conditions.

In Vitro Skin Permeation Methodology for Over-The-Counter Topical Dermatologic Products.

For topically applied over-the-counter (OTC) products, the association of unwanted systemic exposure and adverse events may be difficult to ascertain without a recognition or determination of in vivo absorption. Evaluation of skin permeability using a validated in vitro permeation methodology can provide important information for both initial formulation selection and reformulation during the product life cycle. Additionally, a comparison of permeation rates between formulations using a validated methodology could reduce the number of nonclinical studies needed as part of reformulation.

Effect of Sunscreen Application Under Maximal Use Conditions on Plasma Concentration of Sunscreen Active Ingredients: A Randomized Clinical Trial.

Importance: The US Food and Drug Administration (FDA) has provided guidance that sunscreen active ingredients with systemic absorption greater than 0.5 ng/mL or with safety concerns should undergo nonclinical toxicology assessment including systemic carcinogenicity and additional developmental and reproductive studies.

Objective: To determine whether the active ingredients (avobenzone, oxybenzone, octocrylene, and ecamsule) of 4 commercially available sunscreens are absorbed into systemic circulation.

Navigating sticky areas in transdermal product development.

The benefits of transdermal delivery over the oral route to combat such issues of low bioavailability and limited controlled release opportunities are well known and have been previously discussed by many in the field (Prausnitz et al. (2004) [1]; Hadgraft and Lane (2006) [2]). However, significant challenges faced by developers as a product moves from the purely theoretical to commercial production have hampered full capitalization of the dosage forms vast benefits.

Maximal Usage Trial: An Overview of the Design of Systemic Bioavailability Trial for Topical Dermatological Products.

Dermatologic diseases can present in varying forms and severity, ranging from the individual lesion and up to almost total skin involvement. Pharmacokinetic assessment of topical drug products has previously been plagued by bioanalytical assay limitations and the lack of a standardized study design. Since the mid-1990's the US Food and Drug Administration has developed and implemented a pharmacokinetic maximal usage trial (MUsT) design to help address these issues.

Bioanalytical method validation: concepts, expectations and challenges in small molecule and macromolecule--a report of PITTCON 2013 symposium.

The concepts, importance, and implications of bioanalytical method validation has been discussed and debated for a long time. The recent high profile issues related to bioanalytical method validation at both Cetero Houston and former MDS Canada has brought this topic back in the limelight. Hence, a symposium on bioanalytical method validation with the aim of revisiting the building blocks as well as discussing the challenges and implications on the bioanalysis of both small molecules and macromolecules was featured at the PITTCON 2013 Conference and Expo.

Predicting nonlinear pharmacokinetics of omeprazole enantiomers and racemic drug using physiologically based pharmacokinetic modeling and simulation: application to predict drug/genetic interactions.

Purpose: The objective of this study is to develop a physiologically-based pharmacokinetic (PBPK) model for each omeprazole enantiomer that accounts for nonlinear PK of the two enantiomers as well as omeprazole racemic drug.

Methods: By integrating in vitro, in silico and human PK data, we first developed PBPK models for each enantiomer. Simulation of racemic omeprazole PK was accomplished by combining enantiomer models that allow mutual drug interactions to occur.

Regulatory perspective of bioanalysis from a clinical pharmacology reviewer standpoint: do you see what I see?

Clinical pharmacology plays an important role in drug development, including the evaluation of the drug's pharmacokinetics, pharmacodynamics, drug-interaction potential, exposure-response relationship and safety considerations when being used in specific populations. Clinical pharmacology data is pivotal in ensuring the delivery of the right drug, in the right dose, at the right time, to each particular patient and it has significantly influenced the risk/benefit assessment and labeling recommendations. Consequently, the reliability of the bioanalytical methods and data are of considerable importance, and the solid footing in drug development.

Current challenges in bioequivalence, quality, and novel assessment technologies for topical products.

This paper summarises the proceedings of a recent workshop which brought together pharmaceutical scientists and dermatologists from academia, industry and regulatory agencies to discuss current regulatory issues and industry practices for establishing therapeutic bioequivalence (BE) of dermatologic topical products. The methods currently available for assessment of BE were reviewed as well as alternatives and the advantages and disadvantages of each method were considered. Guidance on quality and performance of topical products was reviewed and a framework to categorise existing and alternative methods for evaluation of BE was discussed.

Clinical pharmacology as a cornerstone of orphan drug development.

A recent US Food and Drug Administration (FDA) advisory committee meeting highlighted the potential of clinical pharmacology to overcome challenges in orphan drug development.

AAPS-FDA workshop white paper: microdialysis principles, application and regulatory perspectives.

Many decisions in drug development and medical practice are based on measuring blood concentrations of endogenous and exogenous molecules. Yet most biochemical and pharmacological events take place in the tissues. Also, most drugs with few notable exceptions exert their effects not within the bloodstream, but in defined target tissues into which drugs have to distribute from the central compartment.