The promoters of OneSource Specialty Pharma Limited, a TPG Growth-backed specialty pharma contract development and manufacturing organisation (CDMO), are in discussions with a clutch of investors including White Oak Capital Management Consultants LLP, Swiss fund HBM Healthcare Investments AG (SWX:HBMN), Tybourne Capital Management Limited and 360 One Wam Limited (NSEI:360ONE), to raise about $200 million (INR 16,700 million), said sources.