Dissolution Testing and 
Acceptance Criteria for 
Immediate-Release Solid Oral 
Dosage Form Drug Products 
Containing High Solubility 
Drug Substances 
 
Guidance for Industry 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
U.S. Department of Health and Human Services 
Food and Drug Administration 
Center for Drug Evaluation and Research (CDER) 
 
August 2018 
Biopharmaceutics 
1074043 FNL 
08/09/18   
Dissolution Testing and 
Acceptance Criteria for 
Immediate-Release Solid Oral 
Dosage Form Drug Products 
Containing High Solubility 
Drug Substances 
 
 
Guidance for Industry
 
Additional copies are available from: 
Office of Communications, Division of Drug Information  
Center for Drug Evaluation and Research 
Food and Drug Administration 
10001 New Hampshire Ave., Hillandale Bldg., 4th Floor  
Silver Spring, MD 20993-0002  
Phone: 855-543-3784 or 301-796-3400; Fax: 301-431-6353 
Email: druginfo@fda.hhs.gov  
http://www.fda.gov/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/default.htm 
 
 
 
 
 
 
 
 
 
 
U.S. Department of Health and Human Services 
Food and Drug Administration 
Center for Drug Evaluation and Research (CDER) 
 
August 2018 
Biopharmaceutics 
 
 
 
  Contains Nonbinding Recommendations 
 
TABLE OF CONTENTS 
 
 
 
I.  INTRODUCTION............................................................................................................. 1 
II.  BACKGROUND ............................................................................................................... 2 
III.   ELIGIBLE DRUG PRODUCTS ..................................................................................... 2 
A.  Dosage Form ................................................................................................................................... 3 
B.  Solubility ......................................................................................................................................... 3 
C.  Therapeutic Index .......................................................................................................................... 3 
D.  Time to Maximum Plasma Concentration................................................................................... 4 
E.  Manufacturing and Testing History ............................................................................................. 4 
F.  Excipients ........................................................................................................................................ 4 
IV.   STANDARD DISSOLUTION TESTING CONDITIONS ............................................ 4 
A.  Basket Method (USP apparatus 1) ............................................................................................... 5 
B.  Paddle Method (USP apparatus 2) ............................................................................................... 5 
V.   DISSOLUTION ACCEPTANCE CRITERIA ............................................................... 5 
VI.  POSTAPPROVAL CONSIDERATIONS.................................................................................... 5 
i 
 
  Contains Nonbinding Recommendations 
 
Dissolution Testing and Acceptance Criteria for Immediate-Release 
Solid Oral Dosage Form Drug Products Containing  
High Solubility Drug Substances 
Guidance for Industry1 
 
 
This guidance represents the current thinking of the Food and Drug Administration (FDA or Agency) on 
this topic.  It does not establish any rights for any person and is not binding on FDA or the public.  You 
can use an alternative approach if it satisfies the requirements of the applicable statutes and regulations.  
To discuss an alternative approach, contact the FDA office responsible for this guidance as listed on the 
title page.   
 
 
 
I.  INTRODUCTION  
 
This guidance is developed to provide manufacturers with recommendations for submission of 
new drug applications (NDAs), investigational new drug applications (INDs), or abbreviated 
new drug applications (ANDAs), as appropriate, for orally administered immediate-release (IR) 
drug products that contain highly soluble drug substances.2  The guidance is intended to describe 
when a standard release test and criteria may be used in lieu of extensive method development 
and acceptance criteria-setting exercises.  This guidance finalizes the guidance for industry on 
Dissolution Testing and Specification Criteria for Immediate-Release Solid Oral Dosage Forms 
Containing Biopharmaceutics Classification System Class 1 and 3 Drugs (August 2015).3  The 
revised title of this guidance better reflects its focus on the solubility of the drug substance in the 
drug product.  Therefore, a direct reference to biopharmaceutics classification system (BCS) 
class 1 and class 3 is not necessary because permeability requirements are not within the focus of 
this guidance.  The recommendations in this guidance clarify the recommendations in the 
guidance for industry on Dissolution Testing of Immediate Release Solid Oral Dosage Forms 
(August 1997) for high solubility drug substances in IR drug products4 that meet the conditions 
described in section III in this guidance.  For drug substances that do not meet the conditions in 
this guidance, sponsors/applicants should follow the recommendations provided in the August 
1997 guidance mentioned above. 
 
                                                 
1 This guidance has been prepared by the Office of Pharmaceutical Quality in the Center for Drug Evaluation and 
Research (CDER) at the Food and Drug Administration. 
2 Drug substance is an active ingredient that is intended to furnish pharmacological activity or other direct effect in 
the diagnosis, cure, mitigation, treatment, or prevention of disease or to affect the structure or any function of the 
human body, but does not include intermediates used in the synthesis of such ingredient.  21 CFR 314.3(b). 
3 We update guidances periodically.  To make sure you have the most recent version of a guidance, check the FDA 
Drugs guidance web page at 
http://www.fda.gov/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/default.htm. 
4 Drug product is a finished dosage form, e.g., tablet, capsule, or solution, that contains a drug substance, generally, 
but not necessarily, in association with one or more other ingredients.  21 CFR 314.3(b). 
 
  1 
  Contains Nonbinding Recommendations 
 
In general, FDAs guidance documents do not establish legally enforceable responsibilities.  
Instead, guidances describe the Agencys current thinking on a topic and should be viewed only 
as recommendations, unless specific regulatory or statutory requirements are cited.  The use of 
the word should in Agency guidances means that something is suggested or recommended, but 
not required.  
 
II.  BACKGROUND 
 
Drug absorption from a solid dosage form after oral administration depends on the release of the 
drug substance from the drug product, the dissolution or solubilization of the drug substance 
under physiological conditions, and the permeation across the gastrointestinal membrane.5,6  
NDAs and ANDAs submitted to FDA contain bioavailability (BA) or bioequivalence (BE) data 
and in vitro dissolution data that, together with chemistry, manufacturing, and controls (CMC) 
data, characterize the quality and performance of the drug product.  In vitro dissolution data are 
generally obtained from: (1) batches used in pivotal clinical and/or BA/BE studies, (2) batches 
used as stability registration batches, and (3) batches used in other human studies conducted 
during product development.  In general, knowledge about the solubility, permeability, 
dissolution, and pharmacokinetics of a drug substance and drug product are considered when 
defining dissolution acceptance criteria as part of the drug approval process.  
 
Immediate-release solid oral dosage form drug products containing high solubility drug 
substances are considered to be relatively low risk regarding the impact of dissolution on in vivo 
performance, provided the in vitro performance meets or exceeds the recommendations 
discussed herein. 
 
This guidance establishes standard dissolution methodology and acceptance criteria that are 
appropriate for highly soluble drug substances that are formulated in IR dosage forms.  The 
availability of these standards will facilitate the rapid development of dissolution methodology 
and related acceptance criteria with no requirement to show discriminatory ability of the 
dissolution method for these products during drug product development.  In addition, these 
standards will facilitate FDAs evaluation of the data submitted in the application. 
 
III.   ELIGIBLE DRUG PRODUCTS 
 
In addition to being an IR dosage form, the drug product should meet all of the following 
conditions in order for the dissolution standards in this guidance to apply.  The FDAs 
Biopharmaceutics Classification System (BCS) guidance should be followed to establish that the 
drug product contains highly soluble drug substance.7  Sponsors/applicants may contact FDA for 
                                                 
5 Amidon GL, Lennernas H, Shah VP, and Crison JR, 1995, A Theoretical Basis for a Biopharmaceutic Drug 
Classification:  The Correlation of In Vitro Drug Product Dissolution and In Vivo Bioavailability, Pharm Res, 
12(3):413-420. 
6 Amidon GL, Lennernas H, Shah VP, and Crison JR, 2014, A Theoretical Basis for a Biopharmaceutic Drug 
Classification: The Correlation of In Vitro Drug Product Dissolution and In Vivo Bioavailability, Pharm Res 12, 
413-420, 1995-Backstory of BCS, The AAPS Journal, 16(5):894-898. 
7 See guidance for industry Waiver of In Vivo Bioavailability and Bioequivalence Studies for Immediate-Release 
Solid Oral Dosage Forms Based on a Biopharmaceutics Classification System. 
 
  2 
  Contains Nonbinding Recommendations 
assistance in applying the BCS guidance or in determining whether a particular drug product 
meets any of the particular conditions listed below.8,9 
A.  Dosage Form 
This guidance applies to solid orally-administered IR drug products, such as tablets and capsules, 
that are meant to be swallowed.  This guidance does not apply to orally disintegrating tablets 
(ODT).10  However, if absorption from the oral cavity can be ruled out for the ODT, then the 
dissolution of the ODT may fall under this guidance.  This guidance also does not apply to 
sublingual dosage forms which can be ODTs as well, as the scientific principles upon which this 
guidance is premised do not apply to the sublingual route of delivery, since sublingual dosage 
forms are intended for absorption in the oral cavity.  This guidance may apply to chewable 
tablets11 if the dissolution studies are conducted on the intact tablets and the product meets the 
conditions described in this guidance. 
B.  Solubility 
To be considered a highly soluble drug product, the drug substance should be considered highly 
soluble with the highest drug products strength12 soluble in 250 mL or less of aqueous media 
over the pH range of 1 to 6.8 at 37C  1C.  In other words, the highest strength divided by 250 
should be less than or equal to the lowest solubility observed over the entire pH range of 1 - 6.8.  
For drug products where the highest single dose administered is higher than the highest strength, 
additional information may be necessary.  The drug substance should be chemically stable at 
least up to the last dissolution time point in the specified dissolution media for the drug product, 
plus the interval of the longest analysis time including sample preparation and chromatography 
run times.  Additional details regarding solubility testing methods can be found in the BCS 
guidance. 
C.  Therapeutic Index 
This guidance does not apply to narrow therapeutic index (NTI) drug products because of the 
critical relationship between the bioavailable dose and clinical performance.  NTI drug products 
pose higher therapeutic risks owing to their associated smaller differences between 
8 For drug products to which the criteria in this guidance apply, the current methods listed in the FDAs Dissolution 
Methods Database will be replaced by the dissolution methods recommended in this guidance, on a case-by-case 
basis, upon submission of supplements in the corresponding NDA or ANDA submission.  For products where the 
dissolution method described in a United States Pharmacopeia (USP) drug product monograph differs from the 
recommendations of this guidance, ANDA applicants may propose to use the approaches in this guidance as an 
updated method and seek revision of the relevant monograph. 
9 When the submission is for an NDA, contact the specific drug products review division with questions.  When the 
submission is for an ANDA, submit a Controlled Correspondence via email to GenericDrugs@fda.hhs.gov.  For the 
definition of a controlled correspondence as well as the process to submit a controlled correspondence, see the 
guidance for industry Controlled Correspondence Related to Generic Drug Development. 
10 See guidance for industry Orally Disintegrating Tablets. 
11 See draft guidance for industry Quality Attribute Considerations for Chewable Tablets.  When final, this guidance 
will represent the FDAs current thinking on this topic. 
12 For ANDAs, the highest strength for which approval is sought. 
3  Contains Nonbinding Recommendations 
 
effective/ineffective and/or toxic/safe doses.  The streamlined approach described in the 
guidance might not be able to detect the batch-to-batch difference(s) that might impact NTI 
performance with respect to safety or efficacy.13 
 
D.  Time to Maximum Plasma Concentration 
 
If the time to maximum plasma concentration is critical to the intended use, this guidance does 
not apply.  For example, labeling claims of early or rapid onset of action (e.g., rapid analgesia, 
rescue medications) exclude the drug product from adoption of the dissolution standard proposed 
herein. 
 
E.  Manufacturing and Testing History 
 
Manufacturing and testing history, including stability testing throughout its shelf-life, should 
demonstrate that the drug product will meet the acceptance criteria in this guidance when using 
the standard dissolution testing conditions described herein.  
 
F.  Excipients 
 
Excipients chosen for drug product formulation should be consistent with the design of IR drug 
products.  Excipients should be included in quantities that are consistent with the excipients 
labeled function and the target population.  Excessive quantities of excipients, such as certain 
sweeteners and surfactants that can impact the drug absorption, may be problematic.  For 
example, mannitol induces a dose proportional decrease in small intestinal transit time.14  When 
this is a factor, we encourage sponsors/applicants to contact FDA9 for guidance on a specific 
drug product.   
 
IV.   STANDARD DISSOLUTION TESTING CONDITIONS 
 
If a drug product meets the eligibility requirements described in section III for a standard 
dissolution method and acceptance criterion, one of the following methods may be used.15  
Information on apparatus and number of units to test can be found in the USP General Chapter 
<711> Dissolution.  The apparatus should be calibrated before use.16 
 
   
                                                 
13 The current approach to establish bioequivalence of NTI drugs is described here: Yu LX, Jiang W, Zhang X, 
Lionberger R, Makhlouf F, Schuirmann DJ, Muldowney L, Chen M L, Davit B, Conner D, Woodcock J, 2015, 
Novel Bioequivalence Approach for Narrow Therapeutic Index Drugs, Clinical Pharmacology & Therapeutics, 
97(3):286-291.  
14 Adkin, D.A., Davis, S.S., Sparrow, R.A., Huckle, P.D., Phillips, A.J., Wilding, I.R., 1995, The effect of different 
concentrations of mannitol in solution on small intestinal transitimplications for drug absorption, Pharm. Res., 12: 
393396. 
15 Shah V, Gurbarg M, Noory A, Dighe S, Skelly J, 1992, Influence of Higher Rates of Agitation on Release 
Patterns of Immediate-Release Drug Products, J Pharm Sci, 81(6): 500-503. 
16 See guidance for industry The Use of Mechanical Calibration of Dissolution Apparatus 1 and 2  Current Good 
Manufacturing Practice (CGMP). 
  4 
  Contains Nonbinding Recommendations 
 
A.  Basket Method (USP apparatus 1) 
 
  Stirring rate = 100 RPM 
  500 mL of 0.1N HCl in aqueous medium 
  No surfactant in medium 
  370.5C 
 
B.  Paddle Method (USP apparatus 2) 
 
  Stirring rate = 50 RPM 
  500 mL of 0.1N HCl in aqueous medium 
  No surfactant in medium 
  370.5C 
 
Although the hydrodynamics of the gastrointestinal tract are complicated and cannot be 
reproduced by the USP basket or paddle apparatus, a rotation speed of 100 RPM has been found 
to be discriminatory for the basket method.  For the paddle method, 50 RPM (or 75 RPM with 
appropriate justification) can be discriminating while minimizing coning effects seen with lower 
stirring rates.15  For the paddle method (USP apparatus 2), it is acceptable to add a few turns of a 
wire helix to ensure that capsule dosage forms are fully immersed in the dissolution bath.  The 
acid conditions of the media reflect the conditions of the stomach whose volume is estimated at 
250 mL when a glass of water is co-ingested with the oral dosage form.  This volume is too low 
to use with the current basket and paddle apparatus; however, 500 mL of medium is commonly 
used and is an appropriate volume of medium for a highly soluble, rapidly dissolving drug 
substance.  The 500 mL dissolution medium should be an appropriate volume to provide sink 
conditions for dissolution of the high soluble drug.  Proper justification should be provided if 900 
mL volume of the medium is used.  Besides the recommended 0.1N HCl in aqueous medium, 
other dissolution media within the physiological pH range may be acceptable if appropriate 
justification is provided. 
 
V.   DISSOLUTION ACCEPTANCE CRITERIA 
 
The drug product dissolution acceptance criterion is based on the high solubility of the drug 
substance.  If an alternate acceptance criterion is proposed, the sponsor/applicant should provide 
additional data to support the proposed acceptance criterion.  Additional supportive information 
could include appropriate in silico modeling in addition to dissolution performance data.  For 
immediate release solid oral drug products containing a high solubility drug substance (as 
defined herein), the dissolution criterion is Q=80% in 30 minutes. 
 
VI.  POSTAPPROVAL CONSIDERATIONS 
 
In regard to post-approval changes, with respect to the dissolution documentation that is needed 
to support the proposed change(s), the recommendations provided in the SUPAC-IR Guidance17 
should be followed. 
                                                 
17 See guidance for industry Immediate Release Solid Oral Dosage Forms: Scale-Up and Postapproval Changes: 
Chemistry, Manufacturing, and Controls, In Vitro Dissolution Testing, and In Vivo Bioequivalence Documentation. 
  5