Acceptability and Disintegration Rates of Orally Disintegrating Risperidone Tablets in Patients with Schizophrenia or Schizoaffective Disorder

Article excerpt

Objective: To investigate the disintegration profile, acceptability, and tolerability of orally disintegrating risperidone tablets in patients with schizophrenia or schizoaffective disorder.

Method: Ten patients stable for at least 10 days on monotherapy with oral risperidone 2 mg to 4 mg taken once daily were switched for 7 days to an equivalent dosage of orally disintegrating risperidone. Visual assessments for time to initial and complete disintegration were collected at each visit. Clinical Global Impression of Severity scores were collected at baseline and at the last visit. Patient acceptance of the new formulation, rated according to a visual analog scale, was obtained at the last visit.

Results: All patients maintained stable clinical status. Mean time to initial disintegration was 5.1 seconds, SD 0.8, and mean time to complete disintegration was 29.4 seconds, SD 18.4. The formulation was rated as very acceptable. Adverse events were reported by 5 patients; all were mild.

Conclusion: The orally disintegrating risperidone tablets were well tolerated and rated as very acceptable by all patients.

(Can J Psychiatry 2004;49:701-703)

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Clinical Implications

* Risperidone orally disintegrating tablets may be an alternative to patients who dislike swallowing traditional tablets.

* This formulation demonstrated faster disintegration than other rapidly disintegrating antipsychotic tablets.

* All patients maintained their clinical response as measured by Clinical Global Impression Severity scores.

Limitations

* The sample size was small and trial duration was short.

* This was a single-centre, open-label trial.

* There was no control group.

Key Words: risperidone, orally disintegrating tablet, schizophrenia

There has been recent interest in the development of different formulations of atypical antipsychotics, including both short-acting and long-acting injections, solutions (that is, liquid concentrates), granules, and orally disintegrating tablets, to address some of the determinants of medication nonadherence in certain clinical situations (1-3). Medication status is an important predictor of outcome in schizophrenia, and nonadherence accounts for more than 50% of relapses (4-6).

Risperidone is an atypical, or novel, antipsychotic that is available in Canada as an oral tablet, a long-acting injection, a solution, and most recently, as an orally disintegrating (orodispersible) tablet (7). This new formulation has been shown to be bioequivalent to the traditional tablet in both healthy volunteers and in patients with schizophrenia (8). It disintegrates rapidly in the mouth, releasing the polacrilex (methacrylic polymer) resin onto which risperidone is bound. The risperidone (still bound to the resin) is swallowed with the saliva and released from the resin in the digestive system. The resin docs not disintegrate or dissolve and is excreted unchanged.

This orally disintegrating formulation can be taken without water. Its main constituents are gelatin A, a coloring agent, and a sweetener (aspartame). It is available in 0.5-mg, 1-mg, and 2-mg mint-flavoured tablets. We report on a pilot trial investigating the disintegration profile, acceptability, and tolcrability of orally disintegrating risperidone tablets in patients with schizophrenia or schizoaffective disorder.

Methods

This single-centre, open-label pilot study was approved by the University of Alberta Review Ethics Board and the Canadian regulatory authority. For inclusion, participants had to meet the following criteria: 1) outpatient, aged 18 to 65 years; 2) DSM-IV diagnosis of schizophrenia or schizoaffective disorder; 3) stable for at least 10 days on monotherapy with once-daily risperidone 2 mg to 4 mg; 4) signed informed consent; 5) ability to comply with visit schedule; 6) physically healthy; and 7) if female, not pregnant and using appropriate measures of birth control while in the study (9). …