Exhibit 5.1

345 Park Avenue New York, NY 10154-1895

Direct 212.407.4935 Main 212.407.4000 Fax 212.407.4990

January 15, 2021

Titan Pharmaceuticals, Inc.
400 Oyster Point Blvd., Suite 505
South San Francisco, CA

Ladies and Gentlemen:

We have acted as counsel to Titan Pharmaceuticals, Inc., a Delaware corporation (the “Company”), in connection with the offering by the Company of 2,275,000 shares of the Company’s common stock, $0.001 par value per share (the “Shares”), pursuant to the Registration Statement on Form S-3 (File No. 333-230742) (the “Registration Statement”) filed with the Securities and Exchange Commission (the “Commission”) under the Securities Act of 1933, as amended (the “Act”), the prospectus dated April 24, 2019 contained in the Registration Statement (the “Base Prospectus”); and the prospectus supplement dated January 15, 2021 filed with the Commission pursuant to Rule 424(b) of the Rules and Regulations of the Act (the “Prospectus Supplement” and, together with the Base Prospectus, the “Prospectus”). The Shares were issued pursuant to a Securities Purchase Agreement dated January 15, 2021 by and among the Company and the purchasers named therein (the “Purchase Agreement”). The Shares are to be sold by the Company as described in the Registration Statement and the Prospectus.

In connection with this opinion, we have examined and relied upon the Registration Statement, the Prospectus and the Purchase Agreement. We have also examined originals or copies, certified or otherwise identified to our satisfaction, of the Company’s certificate of incorporation and bylaws, and such corporate records of the Company and other certificates and documents of officials of the Company, public officials and others as we have deemed appropriate for purposes of this letter. We have assumed the genuineness of all signatures, the authenticity of all documents submitted to us as originals, and the conformity to authentic original documents of all copies submitted to us as conformed and certified or reproduced copies.

Based upon the foregoing and subject to the assumptions, exceptions, qualifications and limitations set forth hereinafter, we are of the opinion that the Shares have been duly authorized for issuance and, when issued and paid for in accordance with the terms and conditions of the Purchase Agreement, the Registration Statement and the Prospectus, will be validly issued, fully paid and nonassessable.

In rendering the foregoing opinion, we have assumed that: (i) the Company will issue and deliver the Shares in the manner contemplated by the Registration Statement and the Prospectus; and (ii) the Shares will be issued in compliance with applicable federal and state securities laws.

We are opining solely on all applicable statutory provisions of Delaware corporate law, including the rules and regulations underlying those provisions, all applicable provisions of the Constitution of the State of Delaware and all applicable judicial and regulatory determinations.

We hereby consent to the filing of this opinion with the Commission as an exhibit to the Current Report on Form 8-K to be filed by the Company in connection with the issuance and sale of the Shares in accordance with the requirements of Item 601(b)(5) of Regulation S−K under the Act and to the reference to our firm therein and in the Prospectus under the caption “Legal Matters.” In giving such consent, we do not thereby admit that this firm is within the category of persons whose consent is required under Section 7 of the Act or the rules and regulations of the Commission under such Section.

Very truly yours,

/s/ Loeb & Loeb LLP

Loeb & Loeb LLP