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Are you aware of the preclinical drug development process? If not, let us simplify it for you
Preclinical drug assessment is that stage which connects the drug discovery phase with the initiation of clinical trials in humans. It is designed for the identification of a lead candidate across several hits; development of the best procedure for scaling up formulation; determination of the routes of exposure, frequency and exposure duration; and finally supporting the clinical trial design.
Clinical drug development or drug research in human subjects is generally comprised of 3 different phases – Phase 1, Phase 2, and Phase 3. ADME (Absorption, Distribution, Metabolism, and Excretion) along with Pharmacokinetic studies, provides useful information to the drug formulation scientists. The parameters of the pK studies such as AUC (Area Under Curve), Tmax (Maximum time at which Cmax is reached), and Cmax (Maximum drug concentration within the bloodstream), etc. At some later drug development stage, the results of these parameters obtained from the pK study are compared with the data collected from early-stage clinical trials. This co-relation helps in the determination of the prediction power of the model under analysis.
Importance of undergoing pharmacokinetic drug testing –
Clinical pharmacokinetic studies are basically aimed at understanding the mechanisms behind the ADME (Absorption, Distribution, Metabolism, and Excretion) process for the drug formulation under analysis. The data results derived from these studies are significant in standardizing the design and conduct of the human clinical trials. Likewise, they are essential for you to understand the efficacy of new drug development and clinical trials. As a clinical technician, it becomes your responsibility to evaluate non-clinical and clinical pharmacokinetic data in conjunction with the non-clinical toxicological and pharmacological studies. This will help you to achieve appropriate and safe conduct of all your clinical trials and evaluate the drug action in the subjects under analysis.
Types of pK studies –
Standard pharmacokinetic study –
This is considered to be a conventional method for the pharmacokinetic drug evaluation in the subject undergoing clinical analysis. Here, you may either expose your subjects to single-dose study or repeated dose studies investigational drug under investigation. The results obtained from the blood and urine samples, and faecal samples (occasionally) will yield a pharmacokinetic profile of the investigational drug formulation.
Population Pharmacokinetic Study Approach –
A population pharmacokinetic study approach is the one where you can use a large number of participants. Still, the samples are small in numbers. Advantages of this type of study are that they are less inconvenient and less strenuous to the subjects.
Pharmacokinetic/Pharmacodynamic Studies (pK/pD studies –
In these types of studies, both the pharmacological response levels and the relative drug concentrations are taken into consideration. A comparative analysis of both these studies will help you in clarifying the dose-response relationship. It also facilitates the response relationships evaluation in terms of drug concentrations, dose regimens, adverse effects, and drug efficacy.
Pharmacokinetic Analysis (pK study analysis)
You can do it either by non-compartmental or compartmental methods. Non-compartmental methods aids in the estimation of drug exposure by a comparative evaluation of AUC from a concentration-time graph. On the other hand, compartmental techniques help in the estimation of these concentration-time graphs by using kinetic models.
On a concluding note, it can be said that the clinical pharmacokinetic studies are the heart of every new drug development process. They are essential both for determination of safety and drug efficacy. It further aids in characterizing the medicinal application of the investigational product for predicting the genotype of drug-metabolizing enzymes and understanding the influence of drug pharmacokinetic interactions.
Thus, pk studies is an important parameter in drug discovery and development as it helps you to analyse the mechanism underlying ADME process more efficiently.