Drug Dissolution in Oral Drug Absorption: Workshop Report.

The in-person workshop "Drug Dissolution in Oral Drug Absorption" was held on May 23-24, 2023, in Baltimore, MD, USA. The workshop was organized into lectures and breakout sessions. Three common topics that were re-visited by various lecturers were amorphous solid dispersions (ASDs), dissolution/permeation interplay, and in vitro methods to predict in vivo biopharmaceutics performance and risk.

High Social Support System among Elderly in a Hilly District: A Descriptive Cross-sectional Study.

Introduction: Social support is an important contributing factor that promotes the health of the elderly by providing them with positive experiences, socially satisfying roles, or the ability to cope with stressful situations. The objective of this research study is to ind out the prevalence of a high social support system among the elderly in a Hilly district.

Methods: A descriptive cross-sectional study was conducted among the elderly from a hilly district of Nepal.

In vitro/in vivo correlations in transdermal product development.

As per the US FDA's guidance for industry entitled 'Extended Release Oral Dosage Forms: Development, Evaluation, and Application of In Vitro/In Vivo Correlations', in vitro-in vivo correlations (IVIVC) can be used to establish a dissolution test as a surrogate for human bioequivalence studies and certain scale-up and postapproval changes. However, at the present time, establishment of a transdermal IVIVC is not used to support biowaiver claims in late phases of clinical development or postapproval changes (major formulation changes, i.e.

Quantification of anandamide, oleoylethanolamide and palmitoylethanolamide in rodent brain tissue using high performance liquid chromatography-electrospray mass spectroscopy.

Reported concentrations for endocannabinoids and related lipids in biological tissues can vary greatly; therefore, methods used to quantify these compounds need to be validated. This report describes a method to quantify anandamide (AEA), oleoylethanolamide (OEA) and palmitoylethanolamide (PEA) from rodent brain tissue. Analytes were extracted using acetonitrile without further sample clean up, resolved on a C18 reverse-phase column using a gradient mobile phase and detected using electrospray ionization in positive selected ion monitoring mode on a single quadrupole mass spectrometer.

Programmable transdermal clonidine delivery through voltage-gated carbon nanotube membranes.

Oral dosage forms and traditional transdermal patches are inadequate for complex clonidine therapy dosing schemes, because of the variable dose/flux requirement for the treatment of opioid withdrawal symptoms. The purpose of this study was to evaluate the in vitro transdermal flux changes of clonidine in response to alterations in carbon nanotube (CNT) delivery rates by applying various electrical bias. Additional skin diffusion studies were carried out to demonstrate the therapeutic feasibility of the system.

Microneedle-assisted percutaneous delivery of naltrexone hydrochloride in yucatan minipig: in vitro-in vivo correlation.

Although microneedle-assisted transdermal drug delivery has been the subject of multiple scientific investigations, very few attempts have been made to quantitatively relate in vitro and in vivo permeation. The case of naltrexone hydrochloride is not an exception. In the present study, a pharmacokinetic profile obtained following a "poke and patch" microneedle application method in the Yucatan minipig is reported.

Development of a codrug approach for sustained drug delivery across microneedle-treated skin.

Microneedle (MN) enhanced transdermal drug delivery enables the transport of a host of molecules that cannot be delivered across the skin by passive diffusion alone. However, the skin being a self-regenerating organ heals itself and thus prevents delivery of molecules through micropores for a 7-day time period, the ideal transdermal delivery goal. Hence, it is necessary to employ a second drug molecule, a cyclooxygenase inhibitor to enhance pore lifetime by decreasing local subclinical inflammatory response following MN treatment.

Programmable transdermal delivery of nicotine in hairless guinea pigs using carbon nanotube membrane pumps.

A compact switchable transdermal nicotine patch device was demonstrated to be effective in vivo in a hairless guinea pig animal model. This required the development and validation of a quantitative method for the simultaneous determination of cotinine and nicotine in hairless guinea pig plasma by liquid chromatography-mass spectrometry. Nicotine metabolism in hairless guinea pigs is rapid and cotinine was found to be the viable nicotine marker.

Diclofenac enables prolonged delivery of naltrexone through microneedle-treated skin.

Purpose: The purpose of this study was to determine if non-specific COX inhibition could extend pore lifetime in hairless guinea pigs following microneedle treatment.

Methods: Hairless guinea pigs were treated with microneedle arrays ± daily application of Solaraze® gel (3% diclofenac sodium (non-specific COX inhibitor) and 2.5% hyaluronic acid); transepidermal water loss was utilized to evaluate pore lifetime.

Challenges and opportunities in dermal/transdermal delivery.

Transdermal drug delivery is an exciting and challenging area. There are numerous transdermal delivery systems currently available on the market. However, the transdermal market still remains limited to a narrow range of drugs.

Programmable transdermal drug delivery of nicotine using carbon nanotube membranes.

Carbon nanotube (CNT) membranes were employed as the active element of a switchable transdermal drug delivery device that can facilitate more effective treatments of drug abuse and addiction. Due to the dramatically fast flow through CNT cores, high charge density, and small pore dimensions, highly efficient electrophoretic pumping through functionalized CNT membrane was achieved. These membranes were integrated with a nicotine formulation to obtain switchable transdermal nicotine delivery rates on human skin (in vitro) and are consistent with a Fickian diffusion in series model.

Cannabidiol bioavailability after nasal and transdermal application: effect of permeation enhancers.

Context: The nonpsychoactive cannabinoid, cannabidiol (CBD), has great potential for the treatment of chronic and 'breakthrough' pain that may occur in certain conditions like cancer. To fulfill this goal, suitable noninvasive drug delivery systems need to be developed for CBD. Chronic pain relief can be best achieved through the transdermal route, whereas 'breakthrough' pain can be best alleviated with intranasal (IN) delivery.

Transdermal delivery of naltrexol and skin permeability lifetime after microneedle treatment in hairless guinea pigs.

Controlled-release delivery of 6-beta-naltrexol (NTXOL), the major active metabolite of naltrexone, via a transdermal patch is desirable for treatment of alcoholism. Unfortunately, NTXOL does not diffuse across skin at a therapeutic rate. Therefore, the focus of this study was to evaluate microneedle (MN) skin permeation enhancement of NTXOL's hydrochloride salt in hairless guinea pigs.

Simultaneous Quantification of Anandamide and Other Endocannabinoids in Dorsal Vagal Complex of Rat Brainstem by LC-MS.

A quantitative method has been developed and validated for the simultaneous determination of anandamide (AEA), docosatetraenylethanolamide (DEA) and N-arachidonyldopamine (NADA) in dorsal vagal complex (DVC) of rat brainstem by liquid chromatographic-electrospray ionization mass spectrometry. The analytes were extracted from the tissue samples of rat brainstem by a single step liquid extraction technique using acetonitrile. The chromatographic separation was conducted on a C18 column using a gradient mobile phase consisting of methanol and water at a flow rate of 0.

Transdermal delivery of bupropion and its active metabolite, hydroxybupropion: a prodrug strategy as an alternative approach.

This investigation includes an evaluation of the percutaneous absorption of bupropion (BUP) and hydroxybupropion (BUPOH) in vitro and in vivo. In addition, a carbamate prodrug of BUPOH (But-BUPOH) was evaluated in vitro. In vitro diffusion studies were conducted in a flow-through diffusion cell system.

In vivo evaluation of a transdermal codrug of 6-beta-naltrexol linked to hydroxybupropion in hairless guinea pigs.

6-Beta-naltrexol is the major active metabolite of naltrexone, NTX, a potent mu-opioid receptor antagonist used in the treatment of alcohol dependence and opioid abuse. Compared to naloxone, NTX has a longer duration of action largely attributed to 6-beta-naltrexol. This study was carried out in order to determine percutaneous absorption of a transdermal codrug of naltrexol, 6-beta-naltrexol-hydroxybupropion codrug (CB-NTXOL-BUPOH), in hairless guinea pigs as well as to evaluate the safety of 6-beta-naltrexol for development as a transdermal dosage form.

Permeation of WIN 55,212-2, a potent cannabinoid receptor agonist, across human tracheo-bronchial tissue in vitro and rat nasal epithelium in vivo.

The aim of this study was to investigate the intranasal absorption of R-(+)-WIN 55,212-2 mesylate in vivo and in vitro. Permeation experiments of R-(+)-WIN 55,212-2 formulations with 2% dimethyl-beta-cyclodextrin (DMbetaCD), 2% trimethyl-beta-cyclodextrin (TMbetaCD) or 2% randomly methylated-beta-cyclodextrin (RAMbetaCD) in 1:1 propylene glycol/saline and 1.5% propylene glycol +3% Tween 80 in saline were conducted using EpiAirway tissue and an anesthetized rat nasal absorption model, respectively.

Near infrared spectrometry for the quantification of human dermal absorption of econazole nitrate and estradiol.

Purpose: The purpose of this study was to demonstrate the use of near-infrared (NIR) spectrometry for the in vitro quantification of econazole nitrate (EN) and estradiol (EST) in human skin.

Methods: NIR spectra were collected from EN and EST powders to verify the presence of NIR chromophores. One percent EN cream, a saturated solution of EN, or 0.

Intranasal absorption of Delta(9)-tetrahydrocannabinol and WIN55,212-2 mesylate in rats.

The aim of this study was to examine the potential of the nasal route for systemic delivery of Delta(9)-tetrahydrocannabinol (Delta(9)-THC) and WIN55,212-2 mesylate. Anesthetized rats were surgically prepared to isolate the nasal cavity, into which Delta(9)-THC (10 mg/kg) or WIN55,212-2 (150 microg/kg) in propylene glycol alone or propylene glycol and ethanol (9:1) were administered. Rats were also administered Delta(9)-THC (1 mg/kg) and WIN55,212-2 (150 microg/kg) intravenously in order to determine absolute bioavailabilities of the nasal doses.

Transdermal delivery of naltrexone and its active metabolite 6-beta-naltrexol in human skin in vitro and guinea pigs in vivo.

The aim of the present study was to evaluate the transdermal delivery of 6-beta-naltrexol (NTXOL), the active metabolite of naltrexone (NTX), across human skin and guinea pig skin in vitro and in hairless guinea pigs in vivo. NTXOL may be responsible for much of NTX's pharmacologic activity. In vitro diffusion studies on NTXOL were compared with similar studies on NTX using a formulation of propylene glycol and buffer in a flow-through diffusion cell system.

In vitro/in vivo correlation of transdermal naltrexone prodrugs in hairless guinea pigs.

Purpose: The purpose of this investigation was to evaluate the in vitro and in vivo percutaneous absorption of the following prodrugs of naltrexone (NTX): 2'-ethylbutyryl-3-O-ester-NTX (ETBUT-ester), methyl-3-O-carbonate-NTX (ME-carbonate), ethyl-3-O-carbamate-NTX (ET-carbamate), and N,N-dimethyl-3-O-carbamate-NTX (DME-carbamate) in hairless guinea pigs.

Methods: In vitro fluxes of NTX and its prodrugs through guinea pig skin were determined using a flow-through diffusion cell system. The pharmacokinetics of NTX prodrugs were determined after topical application of transdermal patches in guinea pigs.

In vivo evaluation of 3-O-alkyl ester transdermal prodrugs of naltrexone in hairless guinea pigs.

Naltrexone (NTX) is a potent competitive antagonist with high affinity for the mu-opioid receptor. Therapeutically, NTX is used for the treatment of alcohol dependence and opioid addiction; however, it does not have the ideal physicochemical properties necessary to achieve therapeutic plasma concentrations via the transdermal route. The aim of the present investigation was to evaluate the in vivo transdermal delivery of three 3-O-alkyl ester prodrugs of NTX, including NTX-3-O-acetate (ACE-NTX), NTX-3-O-propionate (PROP-NTX), and NTX-3-O-hexanoate (HEX-NTX) in hairless guinea pigs.

Development and validation of a liquid chromatography-mass spectrometry method for the quantitation of naltrexone and 6beta-naltrexol in guinea pig plasma.

A quantitative liquid chromatographic-electrospray ionization mass spectrometry method for the determination of naltrexone and 6beta-naltrexol in guinea pig plasma has been developed and validated using naloxone as an internal standard. A single step precipitation-extraction technique was carried out to extract the plasma samples using acetonitrile:ethyl acetate (1:1, v/v). The chromatographic separation was performed on a C(18) column using a mobile phase consisting of 35:65 (v/v) acetonitrile:2 mM ammonium acetate with 0.