LYNN – At least one major drugstore chain will open store-based clinics in Massachusetts following state approval of the stop-and-go mini medical facilities.CVS Caremark spokeswoman Carolyn Castel said the firm will open 25 to 30 “MinuteClinics” in Massachusetts this year and open up to 120 over the next few years.”We expect to begin announcing locations within the next several weeks. Locations would be in all parts of Massachusetts, although I can’t confirm specific locations now,” Castel said.Caremark representatives told state health officials prior to their vote Wednesday approving the clinics that the clinics would be staffed by board-certified family nurse practitioners and physician assistants trained to diagnose, treat and write prescriptions for common illnesses, such as Strep throat and ear, eye, sinus and bronchial infections.There are hundreds of retail-based health clinics nationwide and supporters say they will expand access to health care and help ease conditions at crowded emergency rooms.Critics say the clinics could pose a conflict of interest, putting profits ahead of patients’ health.Lynn Community Health Center Director Robert Dempkowski is concerned that people with ongoing health needs might seek sporadic care at a retail clinic rather than from a primary care physician.”Is this real primary care with continuity? This is a little bit equivalent to a place that just does oil changes rather than full service. It’s quick, episodic care,” he said.MinuteClinic Chief Executive Michael Howe told the state Public Health Council Wednesday that MinuteClinics are approved by The Joint Commission, a national health care licensing body.”MinuteClinic nurse practitioners make it a point to stress the importance of a regular medical exam with every patient they see. If a patient doesn’t have a primary care physician, MinuteClinic will provide a list of physicians in the area who are accepting new patients,” Howe said.