UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549



FORM 10-K/A



(Amendment No. 1)



| | x | ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
| | - | ------------------------------------------------------------------------------------



For the fiscal year ended
December 31, 2019



| |  ̈ | TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
| | - | ----------------------------------------------------------------------------------------



For the transition period from            to

Commission file number 001-38709



Osmotica Pharmaceuticals plc

(Exact name of registrant as specified in
its charter)










|Ireland                         | Not Applicable     
|------------------------------- | -------------------
|(State or other jurisdiction of | (I.R.S. Employer   
|incorporation or organization)  | Identification No.)



400 Crossing Boulevard

Bridgewater, NJ 08807

(Address of principal executive offices)

(Zip Code)



(908) 809-1300

(Registrant’s telephone number, including
area code)



Securities registered pursuant to Section
12(b) of the Act:



|Title of each class                            | Trading
Symbol(s) | Name of each exchange on which registered
|---------------------------------------------- | ----------------- | -----------------------------------------
|Ordinary shares, $0.01 nominal value per share | OSMT              | Nasdaq Global Select Market              



Securities registered pursuant to Section
12(g) of the Act: None



Indicate by check mark if the Registrant
is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes  ̈ No x



Indicate by check mark if the Registrant
is not required to file reports pursuant to Section 13 or 15(d) of the Act. Yes  ̈ No x



Indicate by check mark whether the Registrant
(1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding
12 months (or for such shorter period that the Registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days. Yes x No  ̈



Indicate by check mark whether the registrant
has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405
of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).
Yes x No  ̈



Indicate by check mark whether the registrant
is a large accelerated filer, an accelerated filer, a non-accelerated filer, smaller reporting company, or an emerging growth company.
See definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company”
and “emerging growth company” in Rule 12b-2 of the Exchange Act.



|Large accelerated filer  ̈ | Accelerated filer  ̈ | Non-accelerated filer x | Smaller reporting company x
        Emerging growth company x
|------------------------- | ------------------- | ----------------------- | -------------------------------------------------------------



If an emerging growth company, indicate
by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial
accounting standards provided pursuant to Section 13(a) of the Exchange Act. x



Indicate by check mark whether the Registrant
is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes  ̈
No x



The aggregate market value of the voting
shares held by non-affiliates of the Registrant on June  28, 2019, based upon the closing price of $3.80 of the Registrant’s
ordinary shares as reported on the Nasdaq Global Select Market, was approximately $30.3 million.



Indicate the number of shares outstanding of each of the issuer’s
classes of common stock, as of the latest practicable date.



|Class                                          |  | Outstanding at March 17, 2020
|---------------------------------------------- |  | -----------------------------
|Ordinary shares, $0.01 nominal value per share |  | 58,898,708 shares            



DOCUMENTS INCORPORATED BY REFERENCE



Portions of the registrant’s definitive Proxy Statement for the 2020 Annual Meeting of Shareholders have been filed with the Securities and Exchange Commission
pursuant to Regulation 14A and are incorporated by reference in Part III Items 10-14 of this Annual Report on Form 10-K.


















EXPLANATORY NOTE



This Amendment No. 1 (the “Amendment”) to the Annual
Report on Form 10-K of Osmotica Pharmaceuticals plc (the “Company”) for the fiscal year ended December 31, 2019, originally
filed with the Securities and Exchange Commission (the “SEC”) on March 19, 2020 (the “Original Filing”),
is being filed solely to include revised Exhibits 31.1 and 31.2, which include certain statements required by Item 601(b)(31) of
Regulation S-K inadvertently omitted by the Company when originally filed. This Amendment contains only the cover page, this explanatory
note, the exhibit index, the signature page and the revised exhibits. Because no financial statements are included with this Amendment,
paragraph 3 of the certifications in Exhibits 31.1 and 31.2 has been omitted.



Except for the foregoing, this Amendment does not alter or update
any information contained in the Original Filing. The Original Filing continues to speak as of the date of the Original Filing,
and the Company has not updated the disclosures contained therein to reflect any events that have occurred as of a date subsequent
to the date of the Original Filing. Accordingly, this Amendment should be read in conjunction with the Original Filing and the
Company’s filings made with the SEC subsequent to the Original Filing













ITEM 15. EXHIBITS AND FINANCIAL STATEMENT SCHEDULES



(a) The following documents
are filed as a part of this Amendment.



(3) The following exhibits:



|Exhibit No. | Description
|----------- | -----------



|31.1 | Principal Executive Officer Certification Pursuant to Securities Exchange Act Rules13a-14 and 15d-14 as Adopted Pursuant to
Section 302 of the Sarbanes-Oxley Act of 2002
|---- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------



|31.2 | Principal Financial Officer Certification Pursuant to Securities Exchange Act Rules13a-14 and 15d-14 as Adopted Pursuant to
Section 302 of the Sarbanes-Oxley Act of 2002
|---- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------


















SIGNATURES



Pursuant to the requirements of the Securities Exchange Act
of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.



|                           | Osmotica Pharmaceuticals plc
|-------------------------- | ----------------------------
|                           |                             
|Dated:  September 11, 2020 | By:                         
|                           |                             
|                           |