July 3 (Reuters) - U.S. drug contract manufacturer Catalent Inc said on Tuesday it will buy Juniper Pharmaceuticals Inc for $11.50 per share in cash.

The offer price represents a premium of about 32 percent to Juniper Pharmaceuticals' closing price of $8.70 on Monday and values the company at about $127.7 million, according to Thomson Reuters calculations.

Catalent has a market value of about $5.58 billion, according to Thomson Reuters data.

Juniper Pharmaceuticals shares are up more than 22 percent since January, when the company said it was exploring strategic alternatives.

The deal includes Juniper Pharmaceuticals' U.K. business, Juniper Pharma Services, and is expected to close in the first quarter of 2019, Catalent said in a statement.

Catalent said it would continue to support Juniper's Crinone franchise, a progesterone gel which is its single largest revenue source and marketed by Merck KGaA outside of the United States.

Juniper Pharmaceuticals separately said its board had unanimously approved the deal which represents a total equity value of about $139.6 million on a fully-diluted basis. (Reporting by Philip George in Bengaluru; Editing by Sunil Nair)