OROS® technology employs osmosis to provide precise, controlled drug delivery for up to 24 h and can be used with a range of compounds, including poorly soluble or highly soluble drugs. OROS® technology can be used to deliver high drug doses meeting high drug loading requirements. ALZA's L-OROS™ technology, adapted for liquid formulations, can enhance the bioavailability of drugs with low solubility. This technique has several advantages:
1. Enhanced Bioavailablity: By targeting specific areas of the gastrointestinal tract, OROS® technology may provide more efficient drug absorption and enhanced bioavailability. L-OROS® technology can also enhance the bioavailability of drugs with low solubility.
2. Patterned Delivery: For many drugs, zero-order is not the optimal delivery profile. OROS® can be tailored to meet patterned delivery profiles to optimize a drug's therapeutic efficacy.
3. Reduced Variability: The osmotic driving force of OROS® and protection of the drug until the time of release eliminate the variability of drug absorption and metabolism often caused by gastric pH and motility. OROS® technology employs osmosis to provide precise, controlled drug delivery for up to 24 h and can be used with a range of compounds, including poorly soluble or highly soluble drugs. OROS® technology can be used to deliver high drug doses meeting high drug loading requirements. ALZA's OROS™ technology, adapted for liquid formulations, can enhance the bioavailability of drugs with low solubility.
The new Oros®-system combines both, a fast release of the agent hydromorphone from a tablet for dose-finding and the slow continuous liberation of the opioid for continuous plasma levels (Figure IV-30). Since hydromorphone shows little plasma binding, and is metabolized in only small amounts by the cytochrome-P450-system, clinically active metabolites are not present. Because of the continuous and steady release of the active agent within the gut, there is an effective 24 h duration of action resulting in the need of only one tablet per day. Due to such constant and reliable release, there is:
• a larger patient compliance,
• a natural 24 cycle for intake
• a steady and long duration of analgesia
laser induced opening for drug release
Osmotic pump laser induced opening for drug release
transfer of water through semipermeable membrane
Figure IV-30. Schematic drawing of the mode of action of the osmotic active system Oros® where water migrates through a semipermeable membrane into the tablet resulting in the expansion of a osmotic pump. This leads to a continuous and steady ejection of hydromorphone through a microscopic hole within, out into the gut for reabsorption
The Oros® technology using the prolonged release tablets (Hydromorphone HCl), has has recently been marketed under the brand name Jurnista™. As a new prescription treatment for severe pain it has successfully completed the Mutual Recognition Procedure in Austria, Czech Republic, Estonia, Finland, Germany, Hungary, Italy, Latvia, Lithuania, Norway, Portugal, Slovak Republic, Slovenia and Spain. The countries mutually agreed to recognise the approval of Jurnista™ prolonged-release tablets (Hydromorphone HCl) by the Reference Member State, Denmark. The Hydromorphone HCl prolonged-release tablet was originally developed by ALZA Corporation and utilizes the OROS® Push-Pull delivery system to release the opioid hydromorphone at a consistent rate. It will be registered and marketed by Janssen-Cilag companies in Europe.
As with all opioid analgesics, hydromorphone exerts its pharmacological effects by binding to specific opioid receptors predominantly located on the Central Nervous System (CNS) and smooth muscle. Following oral dosing of Jurnista™ prolonged-release tablets, plasma concentrations reach a broad, relatively flat plateau region within 6-8 h post-dose and remain in this plateau region until approximately 24 h post-dose. This demonstrates that, as intended, hydromorphone is released in a consistent manner from the dosage form, with drug absorption continuing throughout the intestinal tract for approximately 24 h, consistent with once-daily dosing. Jurnista™ is available in four dosage strengths: 8mg, 16 mg, 32 mg and 64 mg prolonged-released tablets.
When switching from another opioid medication to the Oros®-system, the following conversion guide can be used in order to facilitate the change (Figure IV-31).
In clinical trials with Jurnista™ prolonged-release tablets (Hydromorphone HCl), the most commonly reported adverse reactions are constipation, nausea and
vomiting. They can usually be managed by dose reduction, laxatives or antiemetics as appropriate.
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