Can unevenness on the tablet affect its absorption?

A significant effect of irregularities on the surface of the tablet on the process of absorption of the drug is unlikely, although, of course, it can occur. In this case, the quality defect of the medicinal product should be reported to the pharmacy. In addition, if the drug was purchased from a pharmacy and the serialization requirements were met by the pharmacy (QR code verification, withdrawal from the PLMVS system had the correct status), the risk of buying a fake drug is practically zero. I will address more broadly the concerns about the absorption of the medicinal substance. I have no information in the question about what medicine the question concerns. I was also unable to verify the product based on the appearance of the tablet. Nevertheless, it is clear from the description that it is an opioid analgesic. In the case of these drugs, the prolonged-release systems are most often in the form of a polymer matrix that swells when it comes into contact with body fluids, which increases the time it takes to release the drug from the tablet, thus achieving a prolonged release effect. Small irregularities on the tablet should therefore not significantly affect the drug release profile, as the durability of the matrix responsible for the gradual release of the drug is of the greatest importance here. Of course, complete damage to the tablet by crushing/breaking it will change the release profile of the drug. I enclose a study on prolonged-release systems used in analgesics: https://www.akademiamedycyny.pl/wp-content/uploads/2016/05/201101_Farmacja_006.pdf