Good question. The simple answer is that it depends on the discipline and/or the institutional requirements-some may allow this, others may not. You will have to adhere to specific format requirements. For scientific disciplines, original research is most often required. The dissertation often takes the form of a major research paper containing a literature review and the results of an experiment (or experiments) or a theoretical contribution. In the humanities, the dissertation is often a manuscript that is suitable for publication as a book. In any case, your dissertation chair and committee will determine the specific requirements. In general, you will not be permitted to choose something different.

A dissertation must contribute something completely new and undiscovered (or original knowledge) to a particular field or subject. Writing a completely new book may be accepted but a textbook for an established subject, I think, is not acceptable as a dissertation. 

Can a Textbook writing/development acceptable as dissertation to cap the doctoral program?

"Doctoral thesis by research" required a researcher to conduct his / her research for knowledge contribution i.e. can't "reinvent the wheel" as there will be a panel of professors of authority / subject matters experts to examine the thesis.  Typical textbook writing is generally different from a doctoral thesis writing in terms of objective, format & contents.  Even though some theses being published as special textbooks are only happening when the researcher had graduated from his / her doctorate program.  In case your textbook content is similar / equivalent to a doctorate standard of thesis writing, then why not you enroll into a doctoral program first so that you can get your doctorate as well as getting your thesis published as a special textbook?

How about in doctoral program for education? Is it possible for a development of a textbook as a doctoral dissertation?

Harold: Still, your dissertation must contribute something new or original to your field (education). You can write the book later. But of course, you can ask your Dissertation Committee if they will be allowing a "textbook development" as a dissertation, or better, check your Institution's policies and guidelines on dissertation writing. 

No. Not at all. Of course, your research work/new innovations can be a part of book/book chapter.

The answer is 'no'. A dissertation is a research work that must be carried out in the student's area of specialization. Even if it is in education, it has to focus on your specific area of study such as educational management, curriculum studies, Early child/primary education etc. It must also be guided by specialists in that area to ensure originality and contribution to knowledge. The format in which it is presented may vary between institutions but a textbook can never take the place of a PhD dissertation no matter the subject. 

Simply answer the university you are studying in. In Iraqi universities, for example, an answer will be No.