Transdermal delivery of Angiotensin Converting Enzyme inhibitors

Simultaneously Predicting the Pharmacokinetics of CES1-Metabolized Drugs and Their Metabolites Using Physiologically Based Pharmacokinetic Model in Cirrhosis Subjects

Hepatic carboxylesterase 1 (CES1) metabolizes numerous prodrugs into active ingredients or direct-acting drugs into inactive metabolites. We aimed to develop a semi-physiologically based pharmacokinetic (semi-PBPK) model to simultaneously predict the pharmacokinetics of CES1 substrates and their active metabolites in liver cirrhosis (LC) patients. Six prodrugs (enalapril, benazepril, cilazapril, temocapril, perindopril and oseltamivir) and three direct-acting drugs (flumazenil, pethidine and remimazolam) were selected. Parameters such as organ blood flows, plasma-binding protein concentrations, functional liver volume, hepatic enzymatic activity, glomerular filtration rate (GFR) and gastrointestinal transit rate were integrated into the simulation. The pharmacokinetic profiles of these drugs and their active metabolites were simulated for 1000 virtual individuals. The developed semi-PBPK model, after validation in healthy individuals, was extrapolated to LC patients. Most of the observations fell within the 5th and 95th percentiles of simulations from 1000 virtual patients. The estimated AUC and Cmax were within 0.5-2-fold of the observed values. The sensitivity analysis showed that the decreased plasma exposure of active metabolites due to the decreased CES1 was partly attenuated by the decreased GFR. Conclusion: The developed PBPK model successfully predicted the pharmacokinetics of CES1 substrates and their metabolites in healthy individuals and LC patients, facilitating tailored dosing of CES1 substrates in LC patients.

Microneedles and Their Application in Transdermal Delivery of Antihypertensive Drugs-A Review

One of the most cutting-edge, effective, and least invasive pharmaceutical innovations is the utilization of microneedles (MNs) for drug delivery, patient monitoring, diagnostics, medicine or vaccine delivery, and other medical procedures (e.g., intradermal vaccination, allergy testing, dermatology, and blood sampling). The MN-based system offers many advantages, such as minimal cost, high medical effectiveness, comparatively good safety, and painless drug application. Drug delivery through MNs can possibly be viewed as a viable instrument for various macromolecules (e.g., proteins, peptides, and nucleic acids) that are not efficiently administered through traditional approaches. This review article provides an overview of MN-based research in the transdermal delivery of hypertensive drugs. The critical attributes of microneedles are discussed, including the mechanism of drug release, pharmacokinetics, fabrication techniques, therapeutic applications, and upcoming challenges. Furthermore, the therapeutic perspective and improved bioavailability of hypertensive drugs that are poorly aqueous-soluble are also discussed. This focused review provides an overview of reported studies and the recent progress of MN-based delivery of hypertensive drugs, paving the way for future pharmaceutical uses. As MN-based drug administration bypasses first-pass metabolism and the high variability in drug plasma levels, it has grown significantly more important for systemic therapy. In conclusion, MN-based drug delivery of hypertensive drugs for increasing bioavailability and patient compliance could support a new trend of hypertensive drug delivery and provide an alternative option, overcoming the restrictions of the current dosage forms.

Heat-based transdermal delivery of a ramipril loaded cream for treating hypertension

Angiotensin-converting enzyme (ACE) inhibitors play an important role in the development of anti-hypertension approaches, with ramipril being one of the most widely used ACE inhibitor prodrugs orally administered once or twice a day. Due to its low bioavailability, large amounts have to be administered to obtain a therapeutic effect. In this work, we propose a ramipril loaded pharmaceutical formulation in contact with an electrothermal actuator based on a gold nanohole array as an efficient approach to increase the transdermal ramipril flux. Using rats as an in vivo model, the effect on the systolic and diastolic blood pressure is evaluated, showing that under optimized conditions the blood pressure could be regulated. Heat activation resulted in total drug delivery out of a bandage loaded with 1 mg ramipril, revealing a flux of 50.9 ± 2.8 μg cm^-2 h^-1. Importantly, heat-based transdermal dispensing allowed efficient and rapid delivery of ramipril in spontaneously hypertensive rats, with its active form (ramiprilat) detected in blood as early as 5 minutes after delivery onset, accompanied by significant decrease in blood pressure.

The Influence of Microneedles on the Percutaneous Penetration of Selected Antihypertensive Agents: Diltiazem Hydrochloride and Perindopril Erbumine

BACKGROUND

It is well documented in the scientific literature that high blood pressure can lead to cardiovascular disease. Untreated hypertension has clinical consequences such as coronary artery disease, stroke or kidney failure. Diltiazem hydrochloride (DH), a calcium-channel blocker, and perindopril erbumine (PE), an inhibitor of the angiotensin converting enzyme are used for the management of hypertension.

OBJECTIVE

This project will examine the effect of microneedle rollers on the transport of DH and PE across pig ear skin. The use of the transcutaneous route of administration reduces and in sometimes eliminates the trauma and pain associated with injections. Furthermore, there is increased patient compliance. The purpose of this project was to study the effect of stainless steel microneedles on the transdermal delivery of DH and PE.

METHOD

We utilized vertical Franz diffusion cells to study in vitro transport of DH and PE across microneedle- treated pig ear skin. Confocal laser scanning microscopy (CLSM) was used to characterize microchannel depth. Transdermal flux values were determined from the slope of the linear portion of the cumulative amount versus time curve.

RESULTS

There was a 113.59-fold increase in the transdermal permeation of DH following the application of microneedle roller compared to passive diffusion.

CONCLUSION

In the case of PE, there was an 11.99-fold increase in the drug transport across pig skin following the application of microneedle rollers in comparison with passive diffusion. Student's t-test and Mann-Whitney's rank sum test were used to determine statistically significant differences between experimental and control groups.

Heat: A Highly Efficient Skin Enhancer for Transdermal Drug Delivery

Advances in materials science and bionanotechnology have allowed the refinements of current drug delivery systems, expected to facilitate the development of personalized medicine. While dermatological topical pharmaceutical formulations such as foams, creams, lotions, gels, etc., have been proposed for decades, these systems target mainly skin-based diseases. To treat systemic medical conditions as well as localized problems such as joint or muscle concerns, transdermal delivery systems (TDDSs), which use the skin as the main route of drug delivery, are very appealing. Over the years, these systems have shown to offer important advantages over oral as well as intravenous drug delivery routes. Besides being non-invasive and painless, TDDSs are able to deliver drugs with a short-half-life time more easily and are well adapted to eliminate frequent administrations to maintain constant drug delivery. The possibility of self-administration of a predetermined drug dose at defined time intervals makes it also the most convenient personalized point-of-care approach. The transdermal market still remains limited to a narrow range of drugs. While small and lipophilic drugs have been successfully delivered using TDDSs, this approach fails to deliver therapeutic macromolecules due to size-limited transport across the stratum corneum, the outermost layer of the epidermis. The low permeability of the stratum corneum to water-soluble drugs as well as macromolecules poses important challenges to transdermal administration. To widen the scope of drugs for transdermal delivery, new procedures to enhance skin permeation to hydrophilic drugs and macromolecules are under development. Next to iontophoresis and microneedle-based concepts, thermal-based approaches have shown great promise to enhance transdermal drug delivery of different therapeutics. In this inaugural article for the section "Frontiers in Bioengineering and Biotechnology," the advances in this field and the handful of examples of thermal technologies for local and systemic transdermal drug delivery will be discussed and put into perspective.

Transdermal patches: history, development and pharmacology

Transdermal patches are now widely used as cosmetic, topical and transdermal delivery systems. These patches represent a key outcome from the growth in skin science, technology and expertise developed through trial and error, clinical observation and evidence-based studies that date back to the first existing human records. This review begins with the earliest topical therapies and traces topical delivery to the present-day transdermal patches, describing along the way the initial trials, devices and drug delivery systems that underpin current transdermal patches and their actives. This is followed by consideration of the evolution in the various patch designs and their limitations as well as requirements for actives to be used for transdermal delivery. The properties of and issues associated with the use of currently marketed products, such as variability, safety and regulatory aspects, are then described. The review concludes by examining future prospects for transdermal patches and drug delivery systems, such as the combination of active delivery systems with patches, minimally invasive microneedle patches and cutaneous solutions, including metered-dose systems.