Here is a comparison study of risperidone used as an injectable and oral form. Injectables had no use than the orals.

Team@CMHF

Many patients with schizophrenia do not adhere to treatment. Supervised long-acting injections may, therefore, improve treatment success.

A long-acting injectable preparation of risperidone, a second-generation antipsychotic drug, has been available for some years, but randomized trials in patients with stable schizophrenia have shown no advantage over oral treatment.

Now, long-acting risperidone has been compared with oral treatment for patients with unstable schizophrenia.
The long-acting risperidone group had adverse events at the injection site and more extra pyramidal symptoms.

For patients with unstable schizophrenia, long-acting injectable risperidone was no better than oral treatment and caused more adverse effects.

Ref: http://cimsasia.com/India/pub/topic/Medical%20Progress/2011-07/Long-acting%20risperidone%20in%20unstable%20schizophrenia?token=rnp4v0BfyQa5o3iSS1Uv5Ry6TWCP4H8SXzFN8QDJQWsdRem7xvQDxUqlpXN%2bbqvA6iUzZvQ6IIr2oOjhiWgAI%2bL14uZmqjWGMLppaiqv2h5ZuXNr9yeVsEjmZuCg0dxAR10JwzC5Y6bhk60KJ%2fpUn6sUF1gujSV55zwWNIaR%2b1NkyCqW6O1ShF3lBeNXR%2frl9x0NL6birAyMxQ%2fvO5i0xDdzRHJUdCMr8JAlDcSztMI%3d