For tablets to be absorbed, the drug must dissolve after being swallowed. Drugs with low solubility sometimes require the inert ingredients in tablets to help the drug dissolve after being swallowed. This study uses itraconazole as an example drug with low solubility. Itraconazole tablets with different inert ingredients and manufacturing will be administered to healthy volunteers to see if the different inert ingredients and manufacturing impact drug absorption.

Inclusion Criteria:

• Subject is healthy, as determined by screening evaluation that is not greater than 30 days before the first drug study visit
• Subject is male or female between 18 and 65 years of age inclusive.
• Subject is an acceptable candidate for venipuncture.
• Subject is willing to stop all non-routine OTC medications, as well as vitamins, dietary supplements, and herbals, for 24 hours prior to study drug administration and during pharmacokinetic study visits.
• Subject is willing, for each of the four drug study periods, to stop consuming grapefruit, grapefruit products, star fruit, star fruit products, Seville oranges, and St. John's wort from 72-hour before study drug administration until the period's last blood sample
• Subject is willing to not smoke (or use e-cigarettes) during study visits.

Exclusion Criteria:

• Subject has a significant medical disease (including cardiovascular, pulmonary, hematologic, endocrine, immunologic, neurologic, gastrointestinal or psychiatric).
• Subject shows evidence of congestive heart failure or history of congestive heart failure.
• Subject exhibits electrocardiogram (12 lead) with clinically significant abnormalities (e.g. QTcF >450 msec).
• Subject has a history of alcohol or drug abuse, which in the opinion of the investigator, could jeopardize the subject's health or would compromise the subject's ability to participate in this trial.
• Subject is pregnant, breast feeding, or trying to become pregnant.
• Female subject of childbearing potential is unwilling or unable to use a medically acceptable method of contraception throughout the entire study period and for one week after the study is completed. Medically acceptable methods of contraception that may be used by the subject and/or her partner are: oral birth control pill, condom with spermicide, diaphragm with spermicide, IUD, vaginal spermicidal suppository, surgical sterilization of patient or their partner(s), abstinence, or hormonal-based patches, ring, injections, and implants.
• Subject routinely uses (i.e. daily or weekly) prescription medication except hormonal birth control medication, routinely uses (i.e. daily or weekly) OTC medication, or routinely uses (i.e. daily or weekly) St. John's Wort. OTC medications do not include vitamins, dietary supplements, or herbals.
• Subject routinely uses (i.e. daily or weekly) acid blockers, antacids, anti-diarrhea, stimulants, appetite suppressants, or anti-nausea medication or other drugs that modulate GI functio
• Subject is currently taking itraconazole or medication known to interact with itraconazole.
• Subject is allergic to itraconazole.
• Subject has liver impairment as assessed by alanine aminotransferase (ALT), aspartate aminotransferase (AST), or total bilirubin levels greater than the upper limit of normal (ULN).
• Subject has renal impairment as assessed by creatinine clearance lower than 50mL/min/1.73m2, using the CKD-EPI formula.
• Subject is not willing or able to be adherent to study protocol (e.g. study visits).
• Subject has a condition in which in the opinion of the PI or medical physician would increase risk to the subject or interfere with the integrity of the study.
• Subject has received an investigational product within 30 days prior to study drug administration, plans to receive an investigational product during their study participation period, or plans to donate blood to any other clinical trial during their study participation period.
• Subject has provided plasma donation within 1 month of screening or any blood donation/loss more than 500 mL within 8 weeks prior to study drug administration.

Adverse event data were collected from the time enrollment (signed consent) to the last study visit (72-hr blood draw time point).