Get a list of all your inactive ingredients and figure out which ones that will be disolved into available solvents. Similarly, figure out solubility properties for MPH. You can either wash the other crap away from the MPH, or wash the MPH from the other crap, if that makes sense to you. For example, you might be able to rinse your 'gummy' residue with cold, dry ether or another solvent that will not dissolve MPH. Next time you can probably just clean your pills with methanol or IPA.
Methylphenidate hydrochloride USP is a white, odorless, fine crystalline powder. Its solutions are acid to litmus. It is freely soluble in water and in methanol, soluble in alcohol, and slightly soluble in
chloroform and in acetone. Its molecular weight is 269.77.
Metrans XR also contains the following excipients: Butylated hydroxytoluene, carnauba wax, cellulose acetate, hypromellose, isopropyl alcohol, lactose, phosphoric acid, poloxamer, polyethylene glycol, polyethylene oxides, povidone, propylene glycol, sodium chloride, stearic acid, succinic acid, synthetic iron oxides, titanium dioxide and triacetin.