Bioequivalence of a single 10-mg dose of finasteride 5-mg oral disintegrating tablets and standard tablets in healthy adult male Han Chinese volunteers: A randomized sequence, open-label, two-way crossover study

Evidence for the efficacy and safety of tadalafil and finasteride in combination for the treatment of lower urinary tract symptoms and erectile dysfunction in men with benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is an age-related phenomenon associated with prostatic enlargement and bladder outlet obstruction that can cause significant lower urinary tract symptoms (LUTS). These LUTS have a negative impact on an individual's quality of life, which is why treatment of symptomatic BPH has become a major priority. Although surgical interventions exist for treating BPH, pharmacological therapies are often preferred due to their minimal invasiveness and high degree of effectiveness. The three classes of drugs approved for treating BPH include α-blockers, 5-α-reductase inhibitors (5-ARIs) and phosphodiesterase 5 (PDE-5) inhibitors. Individually, each class of drug has been studied and shown to improve symptom relief through a variety of different mechanisms. A more recent focus has been on the development of combinatorial therapies that combine classes of drugs in order to provide maximal benefit. The mTOPS and CombAT studies were the first of their kind to examine whether the combination of 5-ARIs and α-blockers was more effective than monotherapy alone. Both studies found similar results in that the combinatorial therapy was superior to monotherapy. Over the last decade other combinatorial therapies have been at the forefront of investigation. One in particular is the combination of tadalafil, a PDE-5 inhibitor, with finasteride, a 5-ARI. Studies have shown that the combination of tadalafil and finasteride is a safe, effective, and well tolerated treatment for BPH. Evidence suggests that this combination may be particularly effective in reducing treatment-related sexual adverse events associated with 5-ARI treatments. The following review will explore in detail the current evidence surrounding treatment of BPH LUTS using tadalafil and finasteride.

Pharmacokinetic comparison of orally disintegrating and conventional donepezil formulations in healthy Korean male subjects: a single-dose, randomized, open-label, 2-sequence, 2-period crossover study

BACKGROUND

Donepezil is a potent inhibitor of acetylcholinesterase, an enzyme that is targeted in the treatment of Alzheimer's disease.

OBJECTIVE

The purpose of this study was to compare the pharmacokinetic characteristics of orally disintegrating (test) and conventional (reference) donepezil formulations to satisfy the regulatory requirement for marketing.

METHODS

A single-center randomized, single-dose, open-label, 2-way crossover study with a 21-day washout period was conducted in 22 healthy volunteers. Plasma samples for the analysis of donepezil were collected up to 240 hours after drug administration. Participants received either reference or test drug formulation of 10 mg donepezil in the first period and the alternative formulation in the second period. Plasma concentrations of donepezil were determined by validated high-performance liquid chromatography coupled to tandem mass spectrometry detection. Pharmacokinetic parameters, including C(max) and AUC, were determined by noncompartmental analysis. ANOVA was carried out using log-transformed C(max) and AUC, and the mean ratios and their 90% CIs were calculated. The safety profiles and tolerabilities of the 2 formulations were also assessed based on laboratory tests, 12-lead ECGs, vital signs, and physical examinations.

RESULTS

Of the 22 participants initially enrolled, 18 healthy Korean participants completed both treatment periods. Four subjects did not complete both treatments: 3 subjects withdrew consent for personal reasons, and 1 subject experienced adverse events. No significant differences in pharmacokinetic parameters between the 2 formulations were observed. The mean (SD) age, height, and weight of the participants were 25.8 (4.1) years, 173.6 (5.7) cm, and 68.9 (7.8) kg, respectively. The mean (SD) C(max), AUC(last), and AUC(inf) for the reference formulation were 33.26 (6.58) ng/mL, 1521.69 (344.04) ng × h/mL, and 1691.46 (443.05) ng × h/mL, respectively. Corresponding values for the test formulation were 34.23 (6.79) ng/mL, 1554.33 (390.23) ng × h/mL, and 1718.27 (447.03) ng × h/mL, respectively. The median T(max) was 2 hours (range, 1-3 hours) for the reference and test formulations. The geometric mean ratios (90% CI) between the 2 formulations of donepezil were 102.9 (96.8-109.5) for C(max), 102.3 (96.1-108.9) for AUC(last), and 101.6 (95.4-108.2) for AUC(0-∞), respectively. During the study, 15 and 14 adverse events were reported for the reference and test formulations, respectively, and all were transient, mild, and resolved during the treatment period. These adverse events included 7 cases of nausea, 3 cases of headache, and 1 case each of dizziness, vomiting, chills, and sweating. All adverse events were considered related to the study drugs.

CONCLUSION

This study found that the test and reference formulations met the regulatory criteria for pharmacokinetic equivalence in these fasting healthy Korean male subjects. Both donepezil formulations appeared to be generally well tolerated.

Pharmacokinetic profile of total quercetin after single oral dose of tartary buckwheat extracts in rats

As an important edible and medicinal material, tartary buckwheat ( Fagopyrum tataricum Gaertn.) is commonly used as a kind of food or drug in eastern Asian countries. To investigate the pharmacokinetic profile of total quercetin after a single oral dose of tartary buckwheat extract in rats, a sensitive, simple, and accurate HPLC-UV method was developed to determine total quercertin following plasma enzyme hydrolysis with glucuronidase/sulfatase. Eighteen male Wistar rats were randomly assigned into three groups, which were given three different doses of tartary buckwheat extract. The pharmacokinetic results showed that the area under the plasma concentration-time curve (AUC) of total quercetin after single oral doses of tartary buckwheat extract presented a linear relationship. The peak plasma concentrations (C(max)) of total quercetin afte plasma enzyme hydrolysis with glucuronidase/sulfatase were 0.55 ± 0.26, 1.10 ± 0.53, and 2.05 ± 0.26 μg/mL; the peak times (T(max)) were 2.33 ± 1.94, 2.75 ± 3.67, and 2.50 ± 1.82 h; the areas under the curves (AUC(0-36h)) were 5.29 ± 1.35, 10.02 ± 4.43, and 22.51 ± 3.05 μg·mL(-1)·h(-1) for three doses of tartary buckwheat extract (60, 120, and 240 mg/kg). The present study has provided a basic pharmacokinetic profile of total quercetin after a single oral dose of tartary buckwheat extract in rats.

A pilot human pharmacokinetic study and influence of formulation factors on orodispersible tablet incorporating meloxicam solid dispersion using factorial design

Meloxicam (MLX) suffers from poor aqueous solubility leading to slow absorption following oral administration; hence, immediate release MLX tablet is unsuitable in the treatment of acute pain. This study aims to overcome such a drawback by increasing MLX solubility and dissolution using PEG solid dispersion (SD), then, to investigate the feasibility of incorporating the SD into orodispersible tablets (ODTs). A 2(3) full factorial design was employed to investigate the influence of three formulation variables on MLX ODTs. The selected factors: camphor (X(1)) as pore-forming material, and croscarmellose sodium (X(2)) as superdisintegrant, showed significant positive influence, while PEG content (X(3)) was proved to negatively affect both disintegration and wetting times. In addition, isomalt increased disintegration and wetting times when compared to mannitol as diluents. The pharmacokinetic assessment of the optimum ODT formulation in healthy human subjects proved that the faster MLX dissolution by using PEG solid dispersion at pH 6.8 resulted in more rapid absorption of MLX. The rate of absorption of MLX from ODT was significantly faster (p = 0.030) with a significantly higher peak plasma concentration (P = 0.037) when compared to the marketed immediate release MLX tablet with a mean oral disintegration time of 17 ± 3 s.