Fabrication of Extended Release Tablets of Pramipexole: In-vitro Studies

2017 ◽  
Vol 8 (2) ◽  
pp. 115-120 ◽  
Author(s):  
Kambham Venkateswarlu ◽  
Heerasingh Thakur ◽  
Thumati Nagendra Bhaskar Babu
2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Luiz Henrique Corrêa Portari ◽  
Silvia Regina Correa-Silva ◽  
Julio Abucham

Abstract Introduction: Prolactinomas are the most frequent pituitary-secreting tumors. Medical therapy with cabergoline (CAB), a dopamine agonist (DA), is the first line treatment, but 10% of prolactinomas are resistant to CAB. Recently, in vitro studies have shown anti-tumoral activity of metformin and other biguanids in human prolactinomas1, which prompted us to investigate that possibility in vivo. Aim: To evaluate the effect of metformin (MET) on Prolactin (PRL) secretion in patients with CAB resistant prolactinomas. Design and Setting: Prospective interventional study in a single referral center. Subjects: Ten patients (7 M; mean age: 44 ± 12y) with CAB resistant (PRL: 148 ± 125ng/ml; range: 38 - 386) prolactinomas (all macroadenomas) and metabolic syndrome on maximally tolerated CAB doses (4.3 ± 1.2 mg/week; range: 2.0-7.0) for ≥ 6 months (45 ± 39mo; range: 6-120). Intervention: Oral extended release metformin (p.o.) was prescribed according to patient’s tolerance (mean dose: 1.3 ± 0.4 g; range: 1.0-2.0). Main Outcome Measurements: Serum PRL (Elecsys, Roche, Indianapolis, USA), body weight (BW), fasting glycemia (FG) and HbA1C were evaluated before and at two time points during metformin treatment (30-60 and 120-180 days). Results: BW, FG, and/or HbA1C reductions were observed in 9/10 patients and mean FG decreased significantly (P=0.04). No significant changes were observed in serum PRL levels during metformin treatment [134 ± 124 ng/ml vs 138 ± 132 ng/ml vs 144 ± 129 ng/ml, before, at 30-60 days and at 120-180 days, respectively (P=0.499, mixed-effects analysis with the Geisser-Greenhouse correction)]. Individually, two patients exhibited a ≥ 50% decrease in PRL levels at a single timepoint (one at 30-60 days, with a further increase at 120-180 days and the other at 120-180 days). Conclusion: Metformin, at usual doses, did not inhibit prolactin secretion in patients with cabergoline-resistant prolactinomas. The discrepancy between our results and in vitro studies is not clear, but may be related to the much higher concentrations of metformin used in vitro1 as compared to the serum concentrations observed in patients during metformin treatment2. References: 1Gao J et al. Metformin inhibits growth and prolactin secretion of pituitary prolactinoma cells and xenografts. J Cell Mol Med. 2018 22:6368-79; 2 Frid A et al. Novel assay of metformin levels in patients with type 2 diabetes and varying levels of renal function: clinical recommendations. Diabetes Care 2010 33:1291-3.


2018 ◽  
Vol 14 (6) ◽  
pp. 429-436 ◽  
Author(s):  
Shawn A. Kucera, PhD ◽  
Michael S. Zamloot, BS ChE ◽  
Michael M. Crowley, PhD ◽  
Lindsay H. Burns, PhD ◽  
Nadav Friedmann, PhD, MD ◽  
...  

Objective: These in vitro studies compared abuse-deterrent properties of REMOXY ER (extended-release oxycodone), a novel, high-viscosity gel formulation, versus the two currently marketed ER oxycodone formulations.Methods: Tampering methods were tailored to each product to maximize oxycodone release with the least complexity, time, and effort, based on the physical/chemical properties of each formulation. Oral abuse was simulated by extracting oxycodone from each manipulated formulation in Common Ingestible Liquids and in Advanced Solvents (not ingestible and requiring additional separation). To simulate injection abuse, oxycodone was extracted from each manipulated formulation in low volumes of injection vehicles, heated or unheated. Inhalation abuse potential was assessed by volatilization.Results: In oral abuse simulations, manipulated REMOXY ER released 2-22 percent of its oxycodone in 20 minutes in five Common Ingestible Liquids, versus 77-85 percent oxycodone released from OxyContin® ER in 5 minutes in four of the five. In six Advanced Solvents, REMOXY ER released 3-37 percent at 20 minutes, versus 55-89 percent released from OxyContin ER at 5 minutes. Minimal oxycodone was extracted from REMOXY ER in five injection vehicles, heated or unheated. In contrast, OxyContin ER released 65-87 percent of its oxycodone within 10 minutes in all vehicles, regardless of heating. Xtampza® ER released 96 percent of its oxycodone in a heated injection vehicle and released 50-60 percent in two unheated injection vehicles. Showing minimal inhalation abuse potential, 9 percent of oxycodone was vaporized from manipulated REMOXY ER at 20 minutes compared to 8.8 percent at 5 minutes for OxyContin ER.Conclusions: In these studies, REMOXY ER demonstrated robust and meaningful abuse-deterrence relative to OxyContin ER and Xtampza ER.Perspective: Abuse-deterrent drugs were intended to help fight opioid abuse. Yet, the persistence of the opioid epidemic indicates that vast improvements in abuse-deterrent technology are sorely needed. A new, high-viscosity, ER oxycodone formulation showed much improved abuse-deterrent properties in simulations of oral, injection, and inhalation abuse, compared to earlier, first-generation formulations.


2006 ◽  
Vol 15 (04) ◽  
pp. 245-257 ◽  
Author(s):  
H. J. Rolf ◽  
K. G. Wiese ◽  
H. Siggelkow ◽  
H. Schliephake ◽  
G. A. Bubernik

1968 ◽  
Vol 19 (03/04) ◽  
pp. 584-592 ◽  
Author(s):  
Hanna Lukasiewicz ◽  
S Niewiarowski

Summary and Conclusion1. It has been found that EACA does not inhibit activation of human plasminogen into plasmin by SK and UK in a concentration of 5 × 10–2 M. The activation of bovine plasminogen by SK and UK is inhibited by this concentration of EACA but not by a lower one.2. EACA in concentrations of 1,5 × 10–1 – 10–4 M does not inhibit casein proteolysis by plasmin. The proteolysis of fibrinogen and fibrin measured by the release of TCA soluble tyrosine is inhibited by EACA in concentrations of 1,5 × 10–1 – 10–2 M.3. The lysis of non-stabilized clots by plasmin measured in a test tube was inhibited by an EACA concentration of 5 × 10–3 – 5 × 10–4 M. The lysis of stabilized clots by plasmin was inhibited by an EACA concentration of 10–5 M.4. On the basis of experimental findings and data given in literature the authors postulate that the mechanism of the antifibrinolytic effects of EACA consists mainly in a modification of plasmin action on fibrin. These effects are dependent on the structure of the fibrin clots.


1969 ◽  
Vol 21 (02) ◽  
pp. 234-244 ◽  
Author(s):  
N Mackay ◽  
J.C Ferguson ◽  
Antonia Bagshawe ◽  
A.T.T Forrester ◽  
G.P Mcnicol
Keyword(s):  

SummaryAn account is given of the effects of boomslang venom in man. Evidence was found of a fibrinolytic state apparently secondary to the coagulant action of the venom. These features rapidly responded to the administration of specific antivenom. In vitro studies, using a homogenate of boomslang parotids, confirmed the coagulant properties of the venom and showed them to be of much greater potency than the proteolytic actions.


2008 ◽  
Vol 46 (01) ◽  
Author(s):  
F Moriconi ◽  
H Christiansen ◽  
H Christiansen ◽  
N Sheikh ◽  
J Dudas ◽  
...  

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