Population pharmacokinetic model of transdermal nicotine delivered from a matrix-type patch

Nicotine Population Pharmacokinetics in Healthy Smokers After Intravenous, Oral, Buccal and Transdermal Administration

Background

In 4 decades, numerous nicotine replacement therapy products have been developed. Population pharmacokinetic models can support exposure–response modeling and inform nicotine replacement therapy product development, but only limited model-based cross-study population pharmacokinetic analyses for nicotine replacement therapy products have been published.

Objectives

The aim of this retrospective analysis was to assess the population pharmacokinetics of nicotine across intravenous, oral, transdermal and oromucosal (mouth spray, chewing gum, lozenge and inhaler) routes and formulations in healthy smoking subjects.

Methods

Data on 930 unique subjects (46,016 observations) from 29 single- and repeated-dose studies with multiple formulations across intravenous, oral, transdermal and oromucosal routes of administration were included. Data from intravenous and extravascular routes of administration were modelled separately for run efficiency reasons. For developing extravascular models, clearance and disposition parameters and their inter-individual variabilities were fixed to the estimates for intravenously delivered nicotine. Detectable pre-dose nicotine concentrations were modelled as a hypothetical nicotine bolus into the central compartment at the start of wash-out. Modelling repeated-dose oral and buccal administrations required a time-dependent increase in clearance or decrease in bioavailability to describe the data adequately.

Results

Disposition of intravenous nicotine was best described by a three-compartment model with initial and terminal half-lives of 7 min and 4.5 h, respectively, and the absorption of single oral doses was best described with a first-order absorption rate constant of 1.55 h⁻¹. The data of buccal formulations were modelled with parallel oromucosal absorption and gastrointestinal absorption of a part of the dose that is swallowed. For transdermal nicotine, parallel zero- and first-order release from the patch and a transit-compartment absorption model best described the data. Key pharmacokinetic parameters were reliably estimated, with typical values for clearance (67 L/h for a 70-kg subject), volume of distribution (4.3 L/kg), oral bioavailability (40%) and transdermal bioavailability (76%) within expected ranges. The estimated fraction of the dose swallowed for buccal formulations ranged from 55% (gum) to 69% (lozenge).

Conclusions

Robust population pharmacokinetic models were developed for five nicotine replacement therapy product types and for intravenous and oral nicotine. These population pharmacokinetic models are used in exposure–response analyses and simulation-based nicotine replacement therapy product design.

Electronic supplementary material

The online version of this article (10.1007/s40262-020-00960-5) contains supplementary material, which is available to authorized users.

State-of-the-art methods and devices for the generation, exposure, and collection of aerosols from heat-not-burn tobacco products

Tobacco harm reduction is increasingly recognized as a promising approach to accelerate the decline in smoking prevalence and smoking-related population harm. Potential modified risk tobacco products (MRTPs) must undergo a rigorous premarket toxicological risk assessment. The ability to reproducibly generate, collect, and use aerosols is critical for the characterization, and preclinical assessment of aerosol-based candidate MRTPs (cMRTPs), such as noncombusted cigarettes, also referred to as heated tobacco products, tobacco heating products, or heat-not-burn (HNB) tobacco products. HNB tobacco products generate a nicotine-containing aerosol by heating tobacco instead of burning it. The aerosols generated by HNB products are qualitatively and quantitatively highly different from cigarette smoke (CS). This constitutes technical and experimental challenges comparing the toxicity of HNB aerosols with CS. The methods and experimental setups that have been developed for the study of CS cannot be directly transposed to the study of HNB aerosols. Significant research efforts are dedicated to the development, characterization, and validation of experimental setups and methods suitable for HNB aerosols. They are described in this review, with a particular focus on the Tobacco Heating System version 2.2. This is intended to support further studies, the objective evaluation and verification of existing evidence, and the development of scientifically substantiated HNB MRTPs.

Population pharmacokinetic model of transdermal nicotine delivered from a matrix-type patch

AIMS

Nicotine addiction is an issue faced by millions of individuals worldwide. As a result, nicotine replacement therapies, such as transdermal nicotine patches, have become widely distributed and used. While the pharmacokinetics of transdermal nicotine have been extensively described using noncompartmental methods, there are few data available describing the between-subject variability in transdermal nicotine pharmacokinetics. The aim of this investigation was to use population pharmacokinetic techniques to describe this variability, particularly as it pertains to the absorption of nicotine from the transdermal patch.

METHODS

A population pharmacokinetic parent-metabolite model was developed using plasma concentrations from 25 participants treated with transdermal nicotine. Covariates tested in this model included: body weight, body mass index, body surface area (calculated using the Mosteller equation) and sex.

RESULTS

Nicotine pharmacokinetics were best described with a one-compartment model with absorption based on a Weibull distribution and first-order elimination and a single compartment for the major metabolite, cotinine. Body weight was a significant covariate on apparent volume of distribution of nicotine (exponential scaling factor 1.42). After the inclusion of body weight in the model, no other covariates were significant.

CONCLUSIONS

This is the first population pharmacokinetic model to describe the absorption and disposition of transdermal nicotine and its metabolism to cotinine and the pharmacokinetic variability between individuals who were administered the patch.