ObjectivesThe penetration of hydrocortisone (HC) from six topical over-the-counter products along with one prescription cream through cultured normal human-derived epidermal keratinocytes (Epiderm™), mouse skin and synthetic nylon membrane was performed as well as the effect hydrating the skin by pre-washing was explored using the Upright Franz Cell.Method and ResultsPermeation of HC through EpiDerm™, mouse skin and synthetic membrane was highest with the topical HC gel formulation with prewash treatment of the membranes among seven products evaluated, 198 ± 32 µg/cm2, 746.32 ± 12.43 µg/cm2, and 1882 ± 395.18 µg/cm2, respectively. Pre-washing to hydrate the skin enhanced HC penetration through EpiDerm™ and mouse skin. The 24-hour HC released from topical gel with prewash treatment was 198.495 ± 32 µg/cm2 and 746.32 ± 12.43 µg/cm2 while without prewash, the 24-h HC released from topical gel was 67.2 ± 7.41 µg/cm2 and 653.43 ± 85.62 µg/cm2 though EpiDerm™ and mouse skin, respectively. HC penetration through synthetic membrane was ten times greater than through mouse skin and EpiDerm™. Generally, the shape, pattern, and rank order of HC diffusion from each commercial product was similar through each membrane.
The pharmacokinetics (PK) and pharmacodynamics (PD) of clinically relevant doses of repository corticotropin injection (Acthar Gel) and synthetic ACTH1‐24 depot have not been fully characterized. We compared the steroidogenic exposure of repository corticotropin injection and synthetic ACTH1‐24 depot in healthy adults at therapeutic doses using data from 2 separate phase 1 studies. Subjects were randomly assigned to repository corticotropin injection 40 or 80 IU subcutaneously twice weekly or 80 IU subcutaneously 3 times weekly for 15 days or to daily synthetic ACTH1‐24 depot doses of 0.5 mg subcutaneously, 0.75 mg subcutaneously, 1 mg subcutaneously, or 1 mg intramuscularly for 5 days. A population PK/PD model was developed to simulate the free cortisol exposure of a clinically relevant dose of synthetic ACTH1‐24 depot (1 mg subcutaneously twice weekly). Study drug doses were converted to methylprednisolone‐equivalent doses using the steroidogenic exposure of methylprednisolone 16 mg daily as a conversion factor. Doses were also converted to prednisone equivalents using a coefficient of 1.25. These analyses revealed that the steroidogenic exposure of repository corticotropin injection at clinically relevant doses was substantially lower than that for synthetic ACTH1‐24 depot. The 3 repository corticotropin injection regimens were equivalent to approximately 5, 8, and 16 mg of daily prednisone, respectively. On the basis of simulated free cortisol exposure, synthetic ACTH1‐24 depot 1 mg subcutaneously twice weekly was comparable to 57 mg of daily prednisone. These results suggest that repository corticotropin injection has pharmacological effects that cannot be considered identical to synthetic ACTH1‐24 depot.
Twelve hydrophobic coating agents were assessed for their effects on drug release after coating sugar cores by a flexible hot-melt coating method using direct blending. Drug-containing pellets were also produced and used as cores. The cores were coated with single or double wax layers containing acetaminophen (APAP). The harder the wax, the slower the resultant drug releases from single-coated beads. Wax coating can be deposited on cores up to 28% of the beads final weight and reaching 58% with wax and drug. Carnauba-coated beads dissolved in approximately 6 h releasing 80% of the loaded drug. Applying another wax layer extended drug release over 20 h, while still delivering 80% of the loaded drug. When drug-containing pellets (33-58% drug loading) were used as cores, double wax-coated pellets exhibited a near zero-order drug release for 16 h, releasing 80% of the loaded drug delivering 18 mg/h. The simple process of hot-melt coating by direct blending of pellet-containing drug-coated formulations provides excellent options for immediate and sustained release formulations when higher lipid coating or drug loading is warranted. Predicted plasma drug concentration time profiles using convolution and in vitro drug release properties of the beads were performed for optimal formulations.
Objectives: We investigated pharmacokinetic tissue distributions of Levofloxacin to explain adverse tendon incidents. Methods: The pharmacokinetic profiles of single and multiple dosing of 500 mg Levofloxacin following oral and IV infusion administration were simulated. Monte Carlo simulation was used to simulate the drug concentration profiles in plasma and tissue after seven dosing regimens while varying the drug’s elimination and distribution rates to analyze the effects of changing those rates on Levofloxacin accumulation in tissue. Results: Simulated data following oral and IV administration reflect well the reported data (mean simulated plasma Cmax = 6.59 μg/mL and 5.19 μg/mL for IV and oral versus 6.4 μg/mL and 5.2 μg/mL for observed clinical IV and oral route, respectively). Simulations of seven repetitive doses are also in agreement with reported values. Low elimination rates affect the drug concentration in plasma and tissue significantly with the concentration in plasma rising to 35 μg/mL at day 7. Normal elimination rates together with escalation of distribution rates from plasma to tissue increase tissue concentration after 7 doses to 9.5 μg/mL, a value is more than twice that of normal. Conclusions: Simulation can be used to evaluate drug concentration in different tissues. The unexpectedly high concentrations in some cases may explain the reason for tendinopathy in clinical settings.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.