A Clinical Study to Evaluate the Bioavailability Between Two Products Containing Paliperidone 100 mg in the Form of a Prolonged Release Suspension for Injection in Patients With Schizophrenia Who Are Already Stabilized in This Treatment

Inclusion Criteria: * The patient is suffering from Schizophrenia. * The patient age is \> 18 years and \< 65 years old (inclusive). * The patient has a body weight not less than 50 Kg and according to the BMI range (18.5 - 35 Kg/m2), (inclusive) * The patient has received at least 3 doses of Paliperidone 100 mg Prolonged Release Suspension for Injection within the last 3 months. * The patient is under fasting conditions (food and drinks) for at least 8 hours on the day of screening. * The patient is available to volunteer for the entire study duration and is willing to adhere to all protocol requirements. * The findings of the patient are within the range of clinical acceptability in medical history, physical examination, vital signs, ECG, and laboratory results. * The legally acceptable representative signed the informed consent form and the patient is able to communicate with the investigator and comprehend study-related procedures. * The patient agrees to use a condom if he is engaged in sexual activity with a woman of childbearing potential. A condom is required along with another medically acceptable contraceptive method. Medically acceptable methods of contraception include non-hormonal intrauterine device or double barrier method (condom with foam or vaginal spermicidal suppository, diaphragm with spermicide). * Female patients may be included but must comply with the following in order to be included: * Women having the potential to become pregnant can be enrolled only if willing to use a clinically acceptable (i.e. intrauterine device or hormonal contraceptives for at least three months) or a double barrier contraceptive measure (i.e. condom and spermicidal gel or diaphragm and spermicidal gel for at least 14 days) prior to the start of the study and through the study and for 30 days after completion of the study, or * Surgically sterilized for at least 6 months or * Menopausal women, for at least 1 year Exclusion Criteria: * The patient is pregnant or nursing (lactating) women, where pregnancy is defined as the state of the female after conception and until the termination of gestation, confirmed by a positive urine or serum pregnancy test. * The patient has any significant or organ abnormality as determined by the principal investigator/sub-investigator. * The patient has skin abnormalities/irritations at the potential injection site (right or left deltoid) as determined by the Principal Investigator/clinical Sub-Investigator. * The patient has a medical or surgical condition that might interfere with the absorption, metabolism, or excretion of paliperidone. * The patient has known allergy to the Paliperidone Palmitate or to any ingredient in the preparation. * The patient has a history of hypersensitivity to heparin. * The patient intended to significantly change the smoking habits during the trial (i.e. planned cessation or start of smoking career). * The patient will consume alcohol or caffeine or related xanthine containing foods or beverages for 48 hours prior to each dosing. * The patient will consume grapefruit or pomelo-containing beverages and foods within 7 days prior to each dosing. * The patient has a history of or current compulsive abuse of alcohol (more than 10 drinks weekly) or regular exposure to other substance of abuse. * The patient is on a special diet (for example the patient is a vegetarian), or dieting (on a weight lowering plan) during the month before the study. * The patient participated in a comparative bioavailability/ bioequivalence study within the last 90 days before first dose of period I. * The patient participated in a clinical study within the last 90 days before first dose of period I. * The patient donated blood or any of its constituents (1 unit or 350 ml) within the last 90 days before first dose of period I. * The patient has positive testing for HIV I \& II and/or Hepatitis B and/or Hepatitis C using ELISA method. * The patient has positive test for illicit drugs or alcohol before any dose. * The patient is suffering from severe hepatic impairment. * The patient is suffering from renal impairment * Presence or history of clinically significant cardiovascular disease (especially known history of QT prolongation, congenital long QT syndrome, recent acute myocardial infarction, cardiac arrhythmias, or with uncompensated heart failure). * The patient is receiving medicinal products known to prolong the QT interval, e.g. class 1 Antiarrhythmics (e.g., quinidine, disopyramide, procainamide) and class III antiarrhythmics (e.g. amiodarone, sotalol), antihistamines, antipsychotics known to prolong QT interval, and antimalarials (e.g. mefloquine, quinine), tricyclic antidepressants (eg amitriptyline), tetracyclic antidepressants (eg maprotiline). * The patient is receiving centrally acting medicinal products e.g. anxiolytics, risperidone, opiates, etc. or alcohol * The patient is receiving drugs that induce orthostatic hypotension (e,g other antipsychotics, tricyclic). * The patient is receiving medicinal products known to lower the seizure threshold (e.g. phenothiazines or butyrophenones, tricyclics or SSRIs, tramadol, mefloquine, etc.) * The patient is receiving carbamazepine (causes decrease in mean steady state Cmax and AUC of Paliperidone) * The patient has current thoughts of suicide or violent tendencies at screening.