A Study on 2 Different Combination Tablets of Nirmatrelvir Plus Ritonavir to Compare Them With Marketed Paxlovid in Healthy Participants

Medicines that may have different names or be made in different ways but have the same effect on the body are called bioequivalent. The purpose of this study is to learn about the bioequivalence of nirmatrelvir plus ritonavir after taking 2 different combination tablet forms by mouth. These combination tablets are compared to the tablet formulation that is already in the market. This study will be done under fasted conditions in healthy adult participants. This study is seeking participants who are: * Male and non-pregnant female participants aged 18 years and above. * with a body weight of more than 50 kilograms and Body Mass Index (BMI) between 16 to 32 kilograms per meter squared. * are healthy as confirmed by medical history, physical examination, laboratory tests. The study will also look at the safety and tolerability of nirmatrelvir plus ritonavir combination tablet and marketed tablet formulations in healthy adult participants. The study will consist of 4 treatments: Treatment A: Single oral dose of nirmatrelvir plus ritonavir 150 (1 × 150)/100 milligrams marketed tablets under fasted conditions (Reference 1) Treatment B (low dose strength): Single oral dose of nirmatrelvir plus ritonavir 150/100 milligrams (2 × \[75/50 milligrams\]) combination tablets under fasted conditions (Test 1) Treatment C: Single oral dose of nirmatrelvir/ritonavir 300 (2 × 150)/100 milligrams marketed tablets under fasted conditions (Reference 2) Treatment D (high dose strength): Single oral dose of nirmatrelvir/ritonavir 300/100 milligrams (2 × \[150/50 milligrams\]) combination tablets under fasted conditions (Test 2) All treatments will be given under fasted conditions. Fasted condition means the participants would not have had anything to eat before taking the medicines. Around 28 participants will be enrolled in the study. Healthy participants will be tested to see if they can be in the study within 28 days before receiving the study medicine. Selected participants wil